Field-deployable resonant sensor

Abstract

A resonant sensor for detecting environmental health risks is disclosed. The adhesive may include at least one mesoscale or microscale resonator embedded within a material that constitutes at least a portion of the adhesive. The at least one mesoscale or microscale resonator may be formed from a composite material. Further, the at least one mesoscale or microscale resonator may include a plurality of first carbon particles and may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level of the first carbon particles within the at least one mesoscale or microscale resonator.

Description

[Technical Field]

[0001] Related Applications This patent application is an international application claiming priority to U.S. Patent Application No. 18 / 369,418, entitled "FIELD DEPLOYABLE RESONANT SENSORS," filed September 18, 2023. This patent application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 408,372, entitled "RESONANT SENSORS FOR ENVIRONMENTAL HEALTH RISK DETECTION," filed September 20, 2022, and U.S. Provisional Patent Application No. 63 / 463,495, entitled "HAND-THROWN, LAUNCHED AND / OR UNMANNED DEPLOYABLE SENSOR," filed May 2, 2023, all of which are assigned to the assignee of the present application, and the disclosures of all prior applications are deemed part of and incorporated by reference into this patent application.

[0002] Patent application 18 / 369,418 is a continuation-in-part of U.S. patent application Ser. No. 17 / 940,256, entitled "SENSORS INCORPORATED INTO AIRBORNE VEHICLE COMPONENTS TO DETECT PHYSICAL CHARACTERISTIC CHANGES," filed on September 8, 2022, and assigned to the assignee of the present application, the disclosures of all prior applications being deemed part of this patent application and incorporated by reference into this patent application.

[0003] U.S. Patent Application No. 17 / 940,256 is a subsidiary of U.S. Provisional Patent Application No. 63 / 242,270, filed September 9, 2021, entitled "SENSORS INCORPORATED INTO SEMI-RIGID STRUCTURAL MEMBERS TO DETECT PHYSICAL CHARACTERISTIC CHANGES," U.S. Provisional Patent Application No. 63 / 247,680, filed September 23, 2021, entitled "SENSORS INCORPORATED INTO SEMI-RIGID STRUCTURAL MEMBERS TO DETECT PHYSICAL CHARACTERISTIC CHANGES," and U.S. Provisional Patent Application No. 63 / 247,680, filed November 5, 2021, entitled "SENSORS INCORPORATED IN VEHICLE COMPONENTS TO DETECT PHYSICAL CHARACTERISTIC CHANGES." This application claims priority to U.S. Provisional Patent Application No. 63 / 276,274, entitled "SENSORS INCORPORATED INTO AIRBORNE VEHICLE COMPONENTS TO DETECT PHYSICAL CHARACTERISTIC CHANGES," filed on November 22, 2021, and U.S. Provisional Patent Application No. 63 / 281,846, entitled "SENSORS INCORPORATED INTO AIRBORNE VEHICLE COMPONENTS TO DETECT PHYSICAL CHARACTERISTIC CHANGES," filed on November 22, 2021, all of which are assigned to the assignee of the present application, and the disclosures of all prior applications are deemed part of, and incorporated by reference into, this patent application.

[0004] U.S. Patent Application No. 17 / 940,256 is a continuation-in-part of, and claims the benefit of priority to, U.S. Patent Application No. 17 / 227,249, entitled "TUNED RADIO FREQUENCY (RF) RESONANT MATERIALS AND MATERIAL CONFIGURATIONS FOR SENSING IN A VEHICLE," filed April 9, 2021, which in turn is a continuation-in-part of, and claims the benefit of priority to, U.S. Provisional Patent Application No. 63 / 008,262, entitled "RESONANCE SENSING IN TIRES," filed April 10, 2020, and U.S. Provisional Patent Application No. 63 / 008,262, entitled "RESONANCE SENSING IN ELASTOMER-CONTAINING MATERIALS," filed June 9, 2020. This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 036,796, entitled "METHOD OF USE IN A MICROPHOTOMETRIC ELECTRON SYSTEM AND METHODS ...

[0005] U.S. Patent Application No. 17 / 227,249 is a continuation-in-part of, and claims the benefit of priority to, U.S. Patent Application No. 16 / 829,355, entitled "TIRES CONTAINING RESONATING CARBON-BASED MICROSTRUCTURES," filed March 25, 2020, which in turn is a continuation-in-part of, and claims the benefit of priority to, U.S. Provisional Patent Application No. 62 / 985,550, entitled "RESONANT SERIAL NUMBER IN VEHICLE TIRES," filed March 5, 2020; U.S. Provisional Patent Application No. 62 / 979,215, entitled "WASTE ENERGY HARVESTING AND POWERING IN VEHICLES," filed February 20, 2020; and U.S. Provisional Patent Application No. 62 / 979,215, entitled "TUNING RESONANT MATERIALS FOR VEHICLE TIRES," filed March 27, 2019. This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 824,440, entitled "METHOD FOR IMPROVING HYBRID SENSING," all of which are assigned to the assignee of the present application, and the disclosures of all such applications are considered part of, and incorporated by reference into, this patent application.

[0006] U.S. Patent Application No. 17 / 940,256 is a continuation-in-part of, and claims the benefit of priority to, U.S. Patent Application No. 17 / 340,493, entitled "SENSORS INCORPORATED INTO ELASTOMERIC MATERIALS TO DETECT ENVIRONMENTALLY-CAUSED PHYSICAL CHARACTERISTIC CHANGES," filed June 7, 2021. U.S. Patent Application No. 17 / 340,493 is a continuation-in-part of, and claims the benefit of priority to, U.S. Provisional Patent Application No. 63 / 036,118, entitled "CARBON-CONTAINING STICTION SENSORS," filed June 8, 2020, and U.S. Provisional Patent Application No. 63 / 036,118, entitled "SENSORS FOR ELASTOMER PROPERTY CHANGE," filed October 20, 2020. This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 094,223, entitled "RESONANCE SENSING IN ELASTOMER-CONTAINING PRODUCTS," filed on June 9, 2020, and U.S. Provisional Patent Application No. 63 / 036,796, entitled "RESONANCE SENSING IN ELASTOMER-CONTAINING PRODUCTS," filed on June 9, 2020, all of which are assigned to the assignee of the present application, and the disclosures of all prior applications are considered part of, and incorporated by reference into, this patent application.

[0007] U.S. Patent Application No. 17 / 340,493 is also a continuation-in-part of, and claims the benefit of priority to, U.S. Patent Application No. 16 / 829,355, entitled "TIRES CONTAINING RESONATING CARBON-BASED MICROSTRUCTURES," filed March 25, 2020, which in turn claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 824,440, entitled "TUNING RESONANT MATERIALS FOR VEHICLE SENSING," filed March 27, 2019, all of which are assigned to the assignee of the present application, and the disclosures of all prior applications are considered part of, and incorporated by reference into, this patent application.

[0008] FIELD OF THE DISCLOSURE This disclosure relates generally to sensors, and more particularly to incorporating macroscale and mesoscale resonant structures in or on structural members. [Background technology]

[0009] Advances in sensors have created opportunities for further technology integration. This is especially true as vehicles transition to fully autonomous driving and navigation, where technology (as opposed to trained, competent humans) must constantly monitor the performance and reliability of vehicle components to continuously ensure the safety and comfort of vehicle occupants. Traditional systems, such as tire pressure monitoring systems (TPMS) or other electronic or mechanical sensors, may not be able to provide the high fidelity required for high-performance (e.g., racing) or fully autonomous applications. Such applications may present unique challenges, such as the rapid wear of vehicle components (e.g., tires) encountered in demanding driving, the fluctuating vehicle drag profile depending on its environment, or the absence of a human driver available to check vehicle status during vehicle operation. Summary of the Invention [Problem to be solved by the invention]

[0010] Recent advances in sensors enable the detection of health-related environmental conditions (e.g., presence of toxins, presence of radioactivity, etc.). However, further improvements in sensor technology and the development of new modes are desirable. [Means for solving the problem]

[0011] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. It is not intended to identify key features or important features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0012] One innovative aspect of the subject matter described in this disclosure can be implemented as an electromagnetic state sensing device (EMSSD) including split-ring resonators (split-ring resonators) configured to be embedded within a material. Each split-ring resonator can be formed from a three-dimensional (3D) monolithic carbon growth and can respond to an electromagnetic stimulus signal emitted from a user device (e.g., a smartphone, a radio frequency identification (RFID) reader, or a near field communication (NFC) device) and can generate an electromagnetic return signal in response to the electromagnetic stimulus signal. The electromagnetic return signal can indicate the state of the material at a location proximate to the respective split-ring resonator. The split-ring resonator can resonate at a first frequency in response to the electromagnetic stimulus signal when the material is in a first state, and can resonate at a second frequency in response to the electromagnetic stimulus signal when the material is in a second state. The natural resonant frequency of the 3D monolithic carbon growth can be based on the physical properties of the material, such as the permittivity and / or permeability. Thus, the degree of shift in the natural resonant frequency of the first split ring resonator and the second split ring resonator in response to an electromagnetic stimulus signal may indicate the amount of deformation of the material.

[0013] In various embodiments, each split ring resonator may indicate a first state of the material by generating a first electromagnetic return signal in response to the electromagnetic stimulus signal and a second electromagnetic return signal in response to the electromagnetic ping to indicate a second state of the material, and further, the first electromagnetic return signal may have a first frequency and the second electromagnetic return signal may have a second frequency different from the first frequency.

[0014] The state of the material can include deformation of the material. In some aspects, the split ring resonator can indicate deformation of the material by generating a first electromagnetic return signal in response to an electromagnetic stimulus signal and can indicate a lack of deformation of the material by generating a second electromagnetic return signal in response to an electromagnetic ping.

[0015] In some embodiments, at least one split ring resonator includes a resonating portion that can resonate at a first frequency in response to an electromagnetic stimulus signal when the material state is above a threshold and at a second frequency in response to the electromagnetic stimulus signal when the material state is below the threshold. Each of the split ring resonators can include a first split-ring resonator (split ring resonator) containing first carbon particles, where the first carbon particles can uniquely resonate in response to the electromagnetic stimulus signal based on a concentration level of the first carbon particles in the first split ring resonator. Some of the split ring resonators can include a second split ring resonator adjacent to the first split ring resonator containing second carbon particles, where the second carbon particles can uniquely resonate in response to the electromagnetic stimulus signal based at least in part on a concentration level of the second carbon particles in the second split ring resonator.

[0016] Each of the first and second carbon particles may be chemically bonded to the material. In some embodiments, the first carbon particles may include first ferromagnets forming a first porous structure, and the second carbon particles may include second ferromagnets forming a second porous structure. Thus, the amplitude of resonance of the first split ring resonator or the second split ring resonator may indicate the degree of wear of the material. Furthermore, the first split ring resonator may resonate at a first frequency in response to an electromagnetic ping, and the second split ring resonator may resonate at a second frequency in response to the electromagnetic ping, the first frequency being different from the second frequency. Each of the first and second split ring resonators may have a respective attenuation point associated with its frequency response to the electromagnetic ping.

[0017] In some embodiments, the split ring resonators are placed within the structural members of the EVTOL. Furthermore, techniques are disclosed that demonstrate how resonant sensors play an important role in the safety and maneuverability of EVTOL vehicles, as well as the safety and maneuverability of other types of air vehicles.

[0018] In one embodiment, the component may include at least one split-ring resonator (SRR) embedded within a material of the vehicle component and / or the at least one SRR is formed from a three-dimensional (3D) monolithic carbon growth. Further, the at least one SRR may be configured to have a resonant frequency shift in response to at least one of a reversible deformation, stress, or strain of the material.

[0019] In various embodiments, the material may be a non-elastomeric material, a semi-rigid material, and / or a foam-based material. In one embodiment, the foam-based material may amplify the resonant frequency shift. Furthermore, the foam-based material combined with at least one SRR may produce an ensemble frequency effect based on the combination of the resonant frequency shift of the at least one SRR and the frequency response of the foam-based material.

[0020] The vehicle component may be a land vehicle or an air vehicle. Further, the air vehicle may be one of a vertical take-off and landing (VTOL) aircraft, an electric vertical take-off and landing (eVTOL) aircraft, a drone, a passenger drone, a civil aircraft, a military aircraft, or a rocket.

[0021] Furthermore, in some embodiments, the resonant frequency shift can be at a first frequency in response to the electromagnetic ping when the material is in a first state and at a second frequency in response to the electromagnetic ping when the material is in a second state. The resonant frequency shift can be based at least in part on one or more physical properties of the material. Furthermore, the first frequency of the resonant frequency shift can indicate a first state of the material by generating a first electromagnetic return signal in response to the electromagnetic ping, and the second frequency of the resonant frequency shift can indicate a second state of the material by generating a second electromagnetic return signal in response to the electromagnetic ping. The first frequency can be different from the second frequency.

[0022] The resonant frequency shift may be responsive to a reversible deformation of the material. Additionally, the at least one SRR may be configured to indicate a first state of reversible deformation of the material by generating a first electromagnetic return signal in response to the electromagnetic ping and to indicate a second state of reversible deformation of the material by generating a second electromagnetic return signal in response to the electromagnetic ping. Further, the at least one SRR may include a resonating portion, and / or the resonating portion may be configured to resonate at a first frequency in response to the electromagnetic ping when the state of the material is above a threshold and to resonate at a second frequency in response to the electromagnetic ping when the state of the material is below the threshold.

[0023] In various embodiments, the resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or both of the permittivity and magnetic permeability of the material. Additionally, at least one SRR may include a plurality of first carbon particles, which may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on the concentration level of the first carbon particles in the at least one SRR. Additionally, a second SRR may be configured to be embedded within the material of the vehicle component, and / or the second SRR may include a plurality of second carbon particles, which may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on the concentration level of the second carbon particles in the second SRR. Each of the first and second carbon particles may be chemically bonded to the material. Additionally, the first carbon particles may include first ferromagnets that form the first porous structure, and the second carbon particles may include second ferromagnets that form the second porous structure. Furthermore, the amplitude of each resonance of the at least one SRR may indicate the degree of wear of the material, and each SRR of the at least one SRR has an attenuation point. An attenuation point of each SRR of the at least one SRR may be associated with a frequency response to an electromagnetic ping.

[0024] In various embodiments, the adhesive can include at least one mesoscale or microscale resonator embedded within a material that constitutes at least a portion of the adhesive, the at least one mesoscale or microscale resonator being formed from a composite material. Further, the at least one mesoscale or microscale resonator can include a plurality of first carbon particles and be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level of the first carbon particles within the at least one mesoscale or microscale resonator.

[0025] In one embodiment, the at least one mesoscale or microscale resonator may include at least one split ring resonator (SRR). The resonance may be an electromagnetic return signal indicative of a state of the at least one mesoscale or microscale resonator. Furthermore, the state of the at least one mesoscale or microscale resonator may be indicative of at least one of exposure to an analyte, exposure to a biomaterial, or exposure to radiation. The state of the at least one mesoscale or microscale resonator may be correlated to indicate a maximum value of at least one of exposure to an analyte, exposure to a biomaterial, or exposure to radiation. Furthermore, the state may include absorption or adsorption to the material. The adhesive may be configured to resonate at a first frequency in response to an electromagnetic ping when the material is in a first state and to resonate at a second frequency in response to the electromagnetic ping when the material is in a second state. The adhesive may be configured to indicate a degree of adsorption to the material by generating a first electromagnetic return signal in response to the electromagnetic ping and to indicate a lack of adsorption to the material by generating a second electromagnetic return signal in response to the electromagnetic ping.

[0026] In one embodiment, a first set of one or more SRRs may include a plurality of first carbon particles, and the plurality of first carbon particles may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a sensed concentration level of a first analyte. A second set of one or more SRRSs may include a plurality of second carbon particles, and the plurality of second carbon particles may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level of a second analyte. Additionally, each of the first carbon particles and the second carbon particles may be chemically bonded to a material. The first carbon particles may include a first strong aggregate that forms a first porous structure. The second carbon particles may include a second strong aggregate that forms a second porous structure.

[0027] In one embodiment, at least three instances of the adhesive may be used to triangulate the position of the adhesive. The adhesive may be configured to be applied to one of a vertical take-off and landing (VTOL) aircraft, an electric vertical take-off and landing (eVTOL) aircraft, a drone, a passenger drone, a commercial aircraft, a military aircraft, a vehicle, a robot, a body, a box, a personal electronic device, a toolbox, a consumer electronics product, or a rocket. Further, the composite material may include 3D monolithic carbon growth.

[0028] In one embodiment, the tuning resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or more physical properties of the material. The resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or both of the permittivity and permeability of the material. Further, the electromagnetic return signal may have a first frequency and the second electromagnetic return signal may have a second frequency different from the first frequency.

[0029] In one embodiment, the device can include a protective layer over the material. The at least one mesoscale or microscale resonator can include an array of two or more split-ring resonators. Further, each split-ring resonator in the array can be configured to sense at least one of a specific predetermined analyte, a biological agent, a radioisotope, or a specific predetermined volatile substance.

[0030] In various embodiments, the device may include a housing with one of a magnetically permeable skin or holes on an exterior surface of the housing, and at least one sensor embedded within the housing, the at least one sensor configured to respond to a gas or a volatile substance.

[0031] In one embodiment, the at least one sensor may include at least one split ring resonator (SRR). The at least one SRR may be formed from a composite material. The composite material may include a 3D monolithic carbon growth. Additionally, a resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or both of a permittivity and a magnetic permeability of the composite material.

[0032] In one embodiment, the device may be configured to be thrown or fired by hand. Additionally, the housing may be capable of withstanding impact forces. Additionally, the device may be deployed in an enclosed space. The at least one sensor may be configured to detect a specific predetermined compound. The gas or volatile substance may include one of an environmental gas, a flammable gas, a hazardous gas, an illegal gas, a biogas, a vapor, radiation, or an aerosol.

[0033] In one embodiment, the device may be configured to be launched by a launcher and / or may be configured to be deployed using a remotely controlled vehicle or aircraft, or using an autonomous unmanned vehicle or aircraft.

[0034] In one embodiment, at least one SRR comprises a plurality of first carbon particles, and the plurality of first carbon particles may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level of the first carbon particles in the at least one sensor. Additionally, a first set of at least one SRR may comprise a plurality of first carbon particles, and the plurality of first carbon particles may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a sensed concentration level of a first analyte. Furthermore, a second set of at least one SRR may comprise a plurality of second carbon particles, and the plurality of second carbon particles may be configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level of a second analyte. Each of the first and second carbon particles may be chemically bonded to the housing. The first carbon particles may comprise a first ferroelectric mass forming a first porous structure. Furthermore, the second carbon particles may comprise a second ferroelectric mass forming a second porous structure.

[0035] In one embodiment, the tuned resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or more physical properties of the housing. The resonant frequency of the 3D monolithic carbon growth may be based at least in part on one or both of the permittivity and permeability of the housing. The at least one sensor may include an array of split ring resonators, each split ring resonator of the array configured to detect at least one of a specific predetermined analyte, a biological agent, a radioisotope, or a specific predetermined volatile substance. Further, the device may be configured to provide environmental conditions within the enclosed space prior to responders entering.

[0036] The details of one or more embodiments of the inventive subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions of the following figures may not be drawn to scale. [Brief explanation of the drawings]

[0037] [Figure 1]According to one embodiment, an in-situ vehicle control system is presented that includes various sensors formed from carbon-containing composite materials that are tuned to exhibit a desired radio frequency (RF) signal resonance and response when a ping sound is emitted. [Figure 2] 1 illustrates a signal processing system for analyzing emitted and / or returned RF signals that are frequency shifted and / or attenuated by a sensor formed from a carbon-containing RF-tuned resonant material, according to one embodiment. [Figure 3] 1 illustrates a signature class classification system, according to one embodiment. [Figure 4] 1 illustrates a series of tire condition parameters sensed from changes in RF resonance of various layers of carbon-containing RF-tuned resonant material, according to one embodiment. [Figure 5] FIG. 1 shows a schematic diagram of an apparatus used to tune multiple plies of a tire by selecting carbon-containing RF-tuned resonant materials from separate, independent reactors for incorporation into the body of a single tire assembly, according to one embodiment. [Figure 6] 1 illustrates a set of exemplary condition signatures that may be emitted from a new tire formed with a layer of carbon-containing RF-tuned resonant material, according to one embodiment. [Figure 7] 1 illustrates a set of exemplary condition signatures that may be emitted from a new tire formed with a layer of carbon-containing RF-tuned resonant material, according to one embodiment. [Figure 8] FIG. 1 shows a schematic top view of an exemplary split-ring resonator (split-ring resonator) arrangement including two concentric split-ring resonators, according to one embodiment. [Figure 9] FIG. 1 shows a schematic diagram illustrating a complete tire diagnostic system and apparatus for impedance-based spectroscopy tire wear sensing, according to one embodiment. [Figure 10] 1 illustrates a schematic diagram of tire information being transferred via telemetry to a navigation system as well as to equipment for manufacturing printed carbon-based materials, according to one embodiment. [Figure 11]1 illustrates a schematic diagram of tire information being transferred via telemetry to a navigation system as well as to equipment for manufacturing printed carbon-based materials, according to one embodiment. [Figure 12] 1 shows a schematic diagram of a resonant serial number based digital encoding of a vehicle tire by tire tread layer and / or tire body ply print encoding, according to one embodiment. [Figure 13] 1 illustrates the resonance mechanisms that contribute to the ensemble phenomenon resulting from different resonator types in close proximity, according to one embodiment. [Figure 14] 1 is an exemplary temperature sensor including one or more of the split ring resonators of the present disclosure, according to one embodiment. [Figure 15] 1 is a graph of measured resonant signature signal strength (decibels, dB) versus tire tread layer loss height (millimeters, mm) according to one embodiment. [Figure 16] 1 is a graph of measured resonant signature signal strength (in decibels, dB) versus natural resonant frequency of a split ring resonator illustrating a resonant response shift proportional to tire ply deformation, according to one embodiment. [Figure 17] 1 is a graph of signal strength versus chirp signal frequency for a split ring resonator that may resonate in response to an encoded serial number, according to one embodiment. [Figure 18A] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18B] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18C] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18D]1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18E] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18F] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18G] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18H] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18I] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18J] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18K] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18L] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18M] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18N] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18O] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18P] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18Q] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18R] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18S] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18T] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18U] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18V] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18W] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18X] 1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 18Y]1 illustrates a carbon-based material used as a forming material for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. [Figure 19A1] 1 provides a depiction of a split-ring resonator or multiple split-ring resonators placed in concrete before the concrete is poured into a given structural form, according to one embodiment. [Figure 19A2] 1 provides a depiction of a split-ring resonator or multiple split-ring resonators placed in concrete before the concrete is poured into a given structural form, according to one embodiment. [Figure 19B1] 1 shows a depiction of a pillar including a split ring resonator or multiple split ring resonators and an equation for measuring changes in a structural member, according to one embodiment. [Figure 19B2] 1 shows a depiction of a pillar including a split ring resonator or multiple split ring resonators and an equation for measuring changes in a structural member, according to one embodiment. [Figure 20] 20 illustrates the use of split ring resonators externally on structural members of various shapes that have already been used, and provides examples of possible factors and equations that may be important in determining the size, orientation, location, and application of one or more split ring resonators on a structural member, according to one embodiment. [Figure 21] 1 is a flowchart illustrating a process by which a split-ring resonator is implemented for a given application, according to one embodiment. [Figure 22A1] It is presented to illustrate the use of a split ring resonator or multiple split ring resonators in a roadside barrier, according to one embodiment. [Figure 22A2] It is presented to illustrate the use of a split ring resonator or multiple split ring resonators in a roadside barrier, according to one embodiment. [Figure 22A3] It is presented to illustrate the use of a split ring resonator or multiple split ring resonators in a roadside barrier, according to one embodiment. [Figure 22B] 1 depicts roadside barriers used within a racetrack showing structural components that constitute roadside barriers on which one or more split-ring resonators may be placed, according to one embodiment. [Figure 23] 1 shows a depiction of a split-ring resonator placed on the surface of a concrete structure after the concrete has been poured into a given structural formwork, according to one embodiment. [Figure 24A] 1 illustrates a sensing stack including alternating layers of carbon-containing resin and carbon fiber in contact with each other, according to one embodiment. [Figure 24B1] 1 illustrates the frequency shift phenomenon as exhibited by a sensing stack including a carbon-containing RF tuned resonant material, according to one embodiment. [Figure 24B2] 1 illustrates the frequency shift phenomenon as exhibited by a sensing stack including a carbon-containing RF tuned resonant material, according to one embodiment. [Figure 24B3] 1 is a graph illustrating an idealized change in RF resonance as a function of deflection, according to one embodiment. [Figure 24B4] 10 is a graph illustrating the change in RF resonance for a four-layer and five-layer stack, according to one embodiment. [Figure 24C] 1 illustrates a surface sensor deployment in a vehicle area, according to one embodiment. [Figure 25A] 1 provides a depiction of the interaction between a vehicle and a split-ring resonator placed in and / or on the road asphalt, according to one embodiment. [Figure 25B] 1 provides a depiction of how a split ring resonator placed in or on a tire can be used to measure tire stiction, according to one embodiment. [Figure 26] 1 illustrates the placement of split-ring resonators in road asphalt and / or on the road surface, according to one embodiment. [Figure 27] 4 is a flowchart illustrating a process for determining tire stiction, according to one embodiment. [Figure 28]10 illustrates the correlation between measured frequency and tread thickness according to one embodiment. [Figure 29] 1 illustrates a section of a vehicle surface on which an array of individually configured split-ring resonators is disposed, according to one embodiment. [Figure 30] 1 illustrates the placement of split-ring resonators within a frequency bin, according to one embodiment. [Figure 31] 10 shows a chart of detection of time-based variation in deflection as indicated by time-based variation in resonant frequency, according to one embodiment. [Figure 32] 1 illustrates a signature class classification system for processing signals received from a sensor formed from a carbon-containing tuned resonant material, according to one embodiment. [Figure 33] 1 illustrates a depiction of a split ring resonator disposed in and / or on a drone and / or drone platform, according to one embodiment. [Figure 34] 1 shows a depiction of a split-ring resonator disposed in and / or on an air vehicle, according to one embodiment. [Figure 35] 1 illustrates a depiction of a landing position sensor as well as a split ring resonator disposed in and / or on an air vehicle, according to one embodiment. [Figure 36] 1A and 1B show two depictions of a split-ring resonator disposed in and / or on an aircraft, according to one embodiment. [Figure 37A] 1 shows a depiction of a split-ring resonator disposed in and / or on a rocket, according to one embodiment. [Figure 37B] 1 illustrates a depiction of a split ring resonator and landing position sensor located in and / or on a rocket and / or landing platform, according to one embodiment. [Figure 38A] 10 is a flowchart for reporting feedback from a split ring resonator according to one embodiment. [Figure 38B]1 is a flowchart for landing an air vehicle and / or drone using a split ring resonator, according to one embodiment. [Figure 39] 1 shows a depiction of a metamaterial within a dielectric matrix and associated circuitry, according to one embodiment. [Figure 40] 1 shows a depiction of a split-ring resonator embedded in an open-cell or closed-cell material, according to one embodiment. [Figure 41] 1 shows a depiction of a pressure sensor using open or closed cell material, according to one embodiment. [Figure 42] 10 illustrates a depiction of wind pressure sensing data using open or closed cell material, according to one embodiment. [Figure 43] 1 illustrates a depiction of paths and circuits for frequency selective conductivity, according to one embodiment. [Figure 44] 1 shows a depiction of a number of industries in which the use of split ring resonators is applicable, according to one embodiment. [Figure 45] 1 shows a depiction of one or more split ring resonators embedded in an adhesive sticker, according to one embodiment. [Figure 46] 1 shows a depiction of one or more split ring resonators embedded in an adhesive sticker, according to one embodiment. [Figure 47] 1 shows a depiction of one or more split-ring resonators embedded in an adhesive sticker with a protective film, according to one embodiment. [Figure 48] 1 shows a depiction of one or more split ring resonators embedded in an adhesive sticker roll, according to one embodiment. [Figure 49] 1 shows a depiction of one or more split-ring resonators embedded in an adhesive sticker for use in an automobile, according to one embodiment. [Figure 50] 1 shows a depiction of one or more split ring resonators embedded in an adhesive sticker for use in a robot, according to one embodiment. [Figure 51]1 shows a depiction of one or more split-ring resonators embedded in an adhesive sticker for use in an assembly line, according to one embodiment. [Figure 52] 1 shows a depiction of one or more split ring resonators embedded in an adhesive sticker for use on an object in motion with a sensing component, according to one embodiment. [Figure 53] 1 illustrates a deployable sensor including one or more split ring resonators, according to one embodiment. [Figure 54] 1 illustrates a deployable sensor including one or more split ring resonators, according to one embodiment. [Figure 55] 1 illustrates a deployable sensor including one or more split ring resonators on a deployable vehicle, according to one embodiment. [Figure 56] 1 shows a depiction of a deployable sensor including one or more split ring resonators on a remotely controlled vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0038] Like reference numbers and designations in the various drawings indicate like elements.

[0039] Various embodiments of the subject matter disclosed herein generally relate to the development of durable sensors made from carbon-based microstructures.

[0040] Carbon-based materials can be tuned during synthesis to achieve specific, desired radio frequency (RF) signal shift (referring to frequency shift) and signal attenuation (referring to signal magnitude reduction) behavior in response to an emitted RF signal. An instrument capable of emitting an RF signal can include, for example, a transceiver used to interrogate the current resonance of a sensor. Embodiments of the present disclosure require no moving parts. Target RF resonant frequency values ​​of the disclosed component carbon-based materials can be tuned within a reaction chamber or reactor to exhibit interactions that result in targeted performance characteristics. The characteristics can be for any application resonator formed from a specific carbon-based material that exhibits a specified radio frequency (RF) frequency shift and / or signal attenuation, e.g., 0.01 GHz to 100 GHz, that can be tuned depending on the desired application. Regarding tunability, carbon-based materials can grow spontaneously (e.g., self-nucleate) within a reactor from carbon-containing gas-phase species without the need for seed particles to generate complex 3D structures.

[0041] Environmental conditions surrounding the disclosed materials and systems can affect the behavior of the resonator's resonance, frequency shift, and / or signal attenuation.

[0042] The resonators of the present disclosure can be tuned to detect even minute or trace amounts of toxins and / or biological materials and / or radiation. Changes such as these can be detected by transmitting a "ping" of the sensor's current state (e.g., emitting an RF signal followed by observing and analyzing the RF signal) and processing the unique set of detected characteristics (e.g., a "signature"). Various mechanisms for calibrating the observed signal signature and processing the return signature are discussed. Structural members (e.g., rigid members, semi-rigid members, flexible members, sponge-like members, etc.) of mobile or in-motion platforms can incorporate tuned carbon with unique tuned carbon-based microstructures, which can be nanometer-sized, microscale-sized, or mesoscale particles, including structures featuring sizes up to several millimeters (mm).

[0043] As can be seen from the detailed description, the exemplary information presented is intended to illustrate various architectures (including optional ones) and applications. It is strongly noted that this information is set forth for illustrative purposes (to provide as complete a description as possible) and should not be construed as limiting in any way. Any of the following features may be optionally incorporated with or without the exclusion of other features described.

[0044] 1 is a schematic diagram of a vehicle condition sensing system 100 intended to be mounted on a vehicle, such as an automobile and / or truck. The vehicle condition sensing system 100 may include sensors, such as RF-tuned resonant components 108 (e.g., split-ring resonators, as shown in FIG. 8). Each of the RF-tuned resonant components 108 may be formed from a plurality of carbon-based microstructured materials, strong aggregates, weak aggregates, and / or the like, such as those disclosed by Stowell, et al. in U.S. Patent Application No. 16 / 785,020, entitled "3D Self-Assembled Multi-Modal Carbon-Based Particle," filed February 7, 2020 (collectively referred to as "carbon-based materials"), the disclosure of which is incorporated by reference for all purposes. The RF tuned resonant component 108 can be incorporated into any one or more of the belt sensor 104, hose sensor 105, tire sensor 106, and transceiver antenna 102 on a vehicle, such as a traditional driver-driven automobile, or a fully autonomous pod, or vehicle that can operate to move vehicle occupants without a human driver.

[0045] The RF tuned resonant component 108 can be configured to electronically and / or wirelessly communicate, such as by measuring a shift or attenuation of the signal frequency, with any one or more of the transceiver 114, the vehicle central processing unit 116, the vehicle sensor data receiving unit 118, the vehicle actuator control unit 120, and the actuators 122, which may include doors, windows, locks (collectively 124), engine control 126, navigation / heads-up display 128, suspension control 129, and airfoil trim 130. The RF tuned resonant component 108 can induce a shift in the observed frequency of the emitted RF signal via the emitted RF signal 110 and / or via the returned RF signal 112 using the transceiver 114 (referred to as a "frequency shift," which implies any change in frequency). References to a return RF signal 112 corresponding to an emitted RF signal 110 may refer to electronic detection of a frequency shift or attenuation of the emitted RF signal 110 (rather than an actual physical reflection or return of the signal from the sensor) relative to one or more of an RF tuned resonant component 108 integrated with any one or more of a belt sensor 104, a hose sensor 105, a tire sensor 106, a transceiver antenna 102 on the vehicle, and / or the like. The emitted RF signal 110 and the return RF signal 112 may be communicated to (and therefore evaluated by) any one or more of a vehicle central processing unit 116, a vehicle sensor data receiving unit 118, a vehicle actuator control unit 120, and / or an actuator 122. The vehicle condition detection system 100 may be implemented using any suitable combination of software and hardware.

[0046] Any one or more of the various depicted sensors of vehicle condition sensing system 100 can be formed from carbon-based microstructures that are tuned to achieve specific RF resonant behavior when "pinged" (meaning struck or otherwise contacted) by emitted RF signals. Vehicle condition sensing system 100 (or any aspect thereof) can be configured to be implemented in any conceivable vehicle application, area, or environment, such as during adverse weather conditions including sleet, hail, snow, ice, frost, mud, sand, debris, rough terrain, water, and / or the like.

[0047] RF tuned resonant components 108 can be located around and / or on the vehicle (e.g., in the passenger compartment, engine compartment, or trunk of the vehicle, or on the body). As shown in FIG. 1 , the RF tuned resonant components can include a belt sensor 104, a hose sensor 105, a tire sensor 106, and a transceiver antenna 102, any one or more of which may be implemented in newer vehicles during their manufacture, or (alternatively) may be retrofitted to existing vehicles regardless of the vehicle's age and / or condition. RF tuned resonant components 108 can be formed in part using readily available materials such as fiberglass (e.g., for airfoils) or rubber (e.g., for tires) or glass (e.g., for windshields). These conventional materials can be combined with carbon-based materials, growths, weak aggregates, strong aggregates, sheets, particles, and / or the like, which are self-nucleated in-flight from carbon-containing gas-phase species within a reaction chamber or reactor and (1) formulated to improve the mechanical (e.g., tensile, compressive, shear, strain, deformation, and / or the like) strength of the composite material in which they are incorporated, and / or (2) formulated to resonate at a specific frequency or set of frequencies (in the range of 10 GHz to 100 GHz). The variables governing the RF resonant properties and behavior of the material can be controlled independently of the variables responsible for controlling the material strength.

[0048] Radio frequency (RF)-based stimuli (such as those emitted by the transceiver 114 or those emitted by a resonator) can be used to emit RF signals to the RF-tuned resonant component 108, actuator 122 (and / or the like, such as sensors implemented within or on the RF-tuned resonant component 108), which can detect the resonant frequency or frequencies of those RF signals, as well as frequency shifts and patterns (which may be affected by internal or external conditions) observed in the attenuation of the emitted signals. For example, if an RF-tuned resonant component (such as the tire sensor 106) is specially prepared (referred to as being "tuned") to resonate at a frequency of approximately 3 GHz, the tire sensor 106, when stimulated by a 3 GHz RF signal, can resonate or vibrate by resonance (a harmonic phenomenon in which a previously passive string or vibrating body responds to an external vibration with harmonics that resemble the external vibration).

[0049] These resonant oscillations can occur at the stimulated frequency or as harmonics or side lobes derived from the fundamental 3 GHz tone. If a tuned resonant component (of the RF tuned resonant component 108) is tuned to resonate at 2 GHz, when the tuned resonant component is stimulated by a 2 GHz RF signal, the tuned resonant component will emit resonant oscillations as described above. These resonant oscillations can occur at the stimulated frequency or as harmonics or side lobes (in engineering, a local maximum in the far-field radiation pattern of an antenna or other radiation source that is not the main lobe) derived from the fundamental 2 GHz tone. Many additional tuned resonant components can be located proximate to the RF emitter. The RF emitter may be controlled to first emit a 2 GHz ping, then a 3 GHz ping, then a 4 GHz ping, and so on. This series of pings at different and increasing frequencies may be referred to as a "chirp."

[0050] Adjacent tire plies (such as those in contact with one another) within a tire body, as generally illustrated by Figures 5-7, can have different concentration levels or arrangements of carbon-based microstructures to define sensors incorporated within that (referred to individually) tire body ply and / or tread layer to resonate at different, distinct frequencies that are not harmonic with one another. That is, the non-harmonic plies can ensure that certain tire body plies and / or tread layers (or other surfaces or materials) are separately and easily discernibly sensed relative to others with the lowest risk of contamination due to harmonic induced (or otherwise related) signal interference.

[0051] The transceiver 114 (and / or a resonator, not shown in FIG. 1 ) can be configured to transmit the emitted RF signal 110 to any one or more of the RF tuned resonant components 108 and digitally determine the frequency shift and / or attenuation of the return RF signal 112 from any one or more of the RF tuned resonant components 108. Such “return” signals 112 can be processed into digital information that can be electronically communicated to the vehicle's central processing unit 116, which interacts with a vehicle sensor data receiving unit 118 and / or a vehicle actuator control unit 120, which in turn transmits vehicle performance-related signals based on the received sensor data. The return signal 112 can at least partially control an actuator 122. That is, the vehicle actuator control unit 120 may control the actuators 122 to operate any one or more of the doors, windows, locks 124, engine control 126, navigation / heads-up display 128, suspension control 129, and / or airfoil trim 130 according to feedback received from the vehicle sensor data receiving unit 118 regarding wear or degradation of vehicle components as indicated by RF tuned components in communication with the transceiver 114.

[0052] When monitoring the behavior of the return RF signal 111 (e.g., frequency shift and / or attenuation), detection of road debris and adverse weather conditions can, for example, cause the actuator 122 to trigger corresponding changes in the suspension control 129. Such changes can include, for example, loosening the suspension settings to accommodate driving over road debris, followed by tightening the suspension settings to accommodate increased vehicle responsiveness that may be required for driving in heavy rain (and therefore low traction) conditions. The variations in such control by the vehicle actuator control unit 120 are many, and any possible condition external to the vehicle can be detected by the transceiver (as indicated by frequency shift and / or attenuation of the emitted RF signal 110 and / or return RF signal 112).

[0053] Any of the RF-tuned resonant components 108 forming the described sensors can be tuned to resonate when stimulated at a particular frequency, where a defined shift in one or more frequencies (induced by the carbon-based microstructure) can form one or more signal signatures indicative of the material in which the sensor is incorporated or the state of that material.

[0054] The time variation or time deviation (TDEV) of the frequency shift (as shown in the signal signature) in the return RF signal 112 (which refers to the time stability of the phase x relative to the observation interval τ of the measured clock source, so the time deviation forms a standard deviation-type measurement indicative of the time instability of the signal source) can correspond to time-varying variations in the sensor's environment and / or time-varying variations in the sensor itself. Accordingly, a signal processing system (such as any one or more of the vehicle central processing unit 116, the vehicle sensor data receiving unit 118, and / or the vehicle actuator control unit 120) can be configured to analyze signals associated with the sensor (such as the emitted RF signal 110 and the return RF signal 112) according to TDEV principles. Results of such analysis (such as signature analysis) can be delivered to the vehicle central processing unit 116, which can in turn communicate commands to the vehicle actuator control unit 120 for appropriate responsive action. In some configurations, such responsive action by actuators 122 may include at least some input from a human driver, while in other configurations, vehicle state sensing system 100 may function in a completely self-contained manner, thereby enabling a vehicle so equipped to address component performance issues as they arise in a completely driverless setting. Additionally, vehicle central processing unit 116 may be in electronic communication with one or more upstream components 113 (e.g., computing equipment associated with racing applications housed within a stationary domain) and / or a racing mission control unit 119 responsible for capturing and / or processing all data related to RF tuned resonant component 108.

[0055] 2 illustrates a signal processing system 200 for analyzing transmitted and / or returned RF signals that are frequency shifted and / or attenuated by a sensor formed from a carbon-containing RF-tuned resonant material, according to one embodiment. Optionally, signal processing system 200 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that signal processing system 200 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0056] 2 illustrates a block diagram of a signal processing system 200 that may include surface sensors 260 and embedded sensors 270, any one or more of which may be in electronic communication with others regarding environmental changes 250 for a vehicle so equipped (referring to a vehicle equipped with surface sensors 260 and embedded sensors 270). Signal processing system 200 may also include a transceiver 214, a signature analysis module 254, and a vehicle central processing unit 216, any one or more of which may be in electronic communication with others.

[0057] In some implementations, the embedded sensor 270 (which may be embedded in a material such as a tire ply) may use and / or be powered by a built-in power telemetry source that includes a tribological energy generator (not shown in FIG. 2 ). These tribological energy generators may also be embedded in the material in which the sensor is encapsulated. Thus, the tribological energy generator may generate usable current and / or power by, for example, recovering electrostatic charge that builds up between the rotating tire or wheel and the pavement it contacts, to power a resonant circuit (described in further detail herein). The resonant circuit may then resonate and emit an RF signal at a known frequency. As a result, an externally mounted transceiver unit (such as one mounted in each wheel well of the vehicle) may emit the RF signal. In this configuration, the resonant circuit further propagates these RF signals, is powered by tribology, and is embedded in the tire body ply. Similarly, the frequency shift and / or attenuation of the intensity of the emitted signal may be received and analyzed by, for example, the signature analysis module 254 and / or the vehicle central processing unit 216 .

[0058] Embedded power telemetry (which refers to the collection of measurements or other data at a remote or inaccessible point and their automatic transmission to receiving equipment for monitoring) can be incorporated into vehicle tires. The embedded power telemetry referred to herein includes utilizing tribological charge generation within the tire, the storage of that charge, and the subsequent discharge of the stored charge into or through a resonant circuit, using "ringing" (which refers to oscillation of the resonant circuit responsive to further emission of an RF signal) that occurs during the discharge of the resonant circuit (which refers to an electrical circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together and used to generate an RF signal at a specific frequency or frequencies).

[0059] The ping stimulus can be provided in one of two possible configurations for the vehicle component wear detection system of the present disclosure, including reliance on a signal or "ping" generated by a stimulus source, such as a conventional transceiver, located generally outside the tire (or other vehicle component intended to be monitored for wear due to continued use), e.g., embedded in each wheel well of a vehicle so equipped; or the use of tribological energy generators within the tire (which also refers to being embedded in the tire ply, as well as sensors with carbon-based microstructures) that recover energy resulting from the otherwise wasted frictional energy between the rotating wheel and / or tire and the ground or pavement in contact therewith. Tribology, as generally understood and referred to herein, connotes the science and engineering study of interacting surfaces in relative motion. Such tribological energy generators can power in-tire resonating devices, which in turn self-broadcast tire characteristic telemetry.

[0060] Either of the two "ping" stimulus generators or providers discussed above can have complex resonant frequency (CRf) components in the range of approximately 10-99 GHz (e.g., due to the resonant frequencies of small-dimension structures such as graphene platelets), as well as lower frequency resonances in the KHz range due to the relatively larger-dimension discussed intra-tire resonances. In general, CRf can be considered to be equal to a function of the natural resonant frequency of the elastomer component, the natural resonant frequency of the carbon component, the ratio / assembly of the constituent components, and the geometry of the intra-tire resonator.

[0061] The signal processing system 200 functions to analyze a signal signature (defined by digitally observing the frequency shift and / or attenuation of any one or more of the emitted RF signal 210 and / or the return RF signal 212) when the sensor formed from the carbon-based microstructure is stimulated. As a result of stimulation with a chirp signal, the sensor becomes resonant at one of the chirp / ping frequencies and "responds" by resonating at or near its corresponding tuned frequency, shifting the emitted frequency, and / or attenuating the amplitude of the emitted signal. If an environmental change (such as wear of the tire body ply and / or tread layer) occurs while the chirp / ping is being emitted, the "return" signal can be monitored for variations in modulation either above or below the tuned frequency. Thus, the transceiver 214 can be configured to receive the return RF signal 212 representative of the surfaces emitting the pings, emitting pings on or against these surfaces, etc.

[0062] 1-18 is primarily directed to automotive applications of split-ring resonators, it should again be understood that such teachings may be applied to other scenarios and industries detailed herein as well, including concrete, materials science, aerospace, drones and air vehicles, mining materials, oil industry parts, etc. Thus, the teachings herein regarding automobiles (particularly tires) may also be applied to these other industry contexts, some of which are described in detail herein below.

[0063] The chirp / ping signals described above can be emitted by the transceiver 214 (e.g., by inaudible RF signals, pulses, vibrations, and / or similar transmissions). Also, a “return” signal can be received by the transceiver 214. As shown, the chirp signal can occur during a repeating sequence of chirps (e.g., emitted RF signal 210). For example, the chirp signal sequence may be formed from a pattern including a 1 GHz ping, then a 2 GHz ping, then a 3 GHz ping, and so on. The entire chirp signal sequence can be repeated continuously in its entirety. There can be a short period between each ping so that a return signal (return RF signal 212) from the resonant material can be received immediately after the ping ends. Alternatively, or in addition, the signal corresponding to the ping stimulus and the observed “response” signal can occur simultaneously and / or along the same general path or route. The signature analysis module can use digital signal processing techniques to distinguish the observed “response” signal from the ping signal. In situations where the returned response contains energy across many different frequencies (harmonics, side lobes, etc.), a notch filter can be used to filter the stimulus. The returned signal received by the transceiver can be transmitted to the signature analysis module 254, which in turn can transmit the processed signal to the vehicle central processing unit 216. The preceding discussion of Figure 2 includes a discussion of sensors formed from carbon-containing tuned resonant materials and may also reference sensing stacks as well.

[0064] The disclosed sensors may be incorporated into tire plies, including resin layers that may be layered between additional carbon fiber layers within the tire ply. Each carbon-containing resin layer may be separately formulated to resonate at a different intended or desired tuned frequency. The physical phenomenon of material resonance may be explained in terms of corresponding molecular composition. For example, a layer having a defined first structure, such as a first molecular structure, may resonate at a first frequency, while a layer having a different second molecular structure may resonate at a different second frequency.

[0065] A material contained within a layer with a particular molecular structure resonates at a first tuning frequency when the layer is in a low-energy state and at a different second frequency when the material within the layer is in an induced high-energy state. For example, a material within a layer exhibiting a particular molecular structure can be tuned to resonate at 3 GHz when the layer is in its natural, undeformed, low-energy state. In contrast, the same layer can resonate at 2.95 GHz when the layer is at least partially deformed from its natural, undeformed, low-energy state. As a result, this phenomenon can be tailored to address the need for high-fidelity and precision detection of even the slightest anomalies, such as those on a tire surface that contacts a road surface such as pavement and experiences severe wear at specific localized contact areas. Race cars racing on demanding race circuits (referring to highly technical, windy tracks characterized by sharp turns and rapid elevation changes) can benefit from such localized tire wear or degradation information to make informed tire replacement decisions, even under time-sensitive race-day conditions.

[0066] With reference to the above, the frequency shift phenomenon (such as the transition from a resonance at a frequency of 3 GHz to 2.95 GHz) can be illustrated and discussed with reference to Figures 24B1-24B2, described herein below.

[0067] Carbon-containing materials (such as those containing carbon-based microstructures) that are tuned to exhibit specific resonant frequencies when pinged by an RF signal can be tuned to exhibit specific resonant profiles by creating specific compounds that combine these materials to have specific electrical impedances. Similarly, different electrical impedances correspond to different frequency response profiles.

[0068] Impedance describes the difficulty that alternating current (AC) flows through an element. In the frequency domain, impedance is a complex number with a real and an imaginary component due to the structure behaving as an inductor. The imaginary component is the inductive reactance (the resistance of a circuit element to the flow of current due to its inductance or capacitance; the greater the reactance, the smaller the current for the same applied voltage). L which is based on the frequency f and inductance L of a particular structure in the following equation: X L =2πfL (Equation 1)

[0069] As the received frequency increases, the reactance also increases, so that at a certain frequency threshold, the measured strength (amplitude) of the transmitted signal can be attenuated. Inductance L is affected by the electrical impedance Z of the material, which is related to the material properties of magnetic permeability μ and permittivity ε by the following relationship:

number

[0070] Therefore, tuning the material properties affects the electrical impedance Z, which in turn affects the inductance L and therefore the reactance X. L changes to affect

[0071] Carbon-containing structures with different inductances, such as those disclosed by Anzelmo, et al. in U.S. Patent No. 10,428,197, entitled "Carbon and Elastomer Integration," issued October 1, 2019, which is incorporated herein by reference in its entirety, can exhibit different frequency responses (when used to create sensors in the aforementioned systems). That is, a carbon-containing structure with a higher inductance L (based on electrical impedance Z) will reach a certain reactance at a lower frequency than another carbon-containing structure with a lower inductance.

[0072] When formulating a compound to tune a particular electrical impedance, the material properties of magnetic permeability, permittivity, and conductivity can also be considered. Furthermore, if a first carbon-containing structure resonates at a first frequency, but the structure is subjected to a tension-inducing condition, such as when a second carbon-containing structure is slightly deformed (which slightly changes the physical properties of the structure), the structure is observed to resonate at a second frequency.

[0073] An exemplary carbon-containing structure (e.g., as shown in FIGS. 18A-18Y) may resonate at a first frequency f that can be related to an equivalent electrical circuit including a capacitor C1 and an inductor L1. The frequency f1 is given by:

number

[0074] When a carbon-containing structure is deformed, the inductance and / or capacitance of the structure may change. These changes can be correlated to an equivalent electrical circuit including capacitor C2 and inductor L2. The frequency f2 is given by:

number

[0075] 3 illustrates a signature class classification system 300 according to one embodiment. Optionally, the signature class classification system 300 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that the signature class classification system 300 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0076] The signature classification system 300 processes signals received from sensors formed from a carbon-containing tuned resonant material. The signature classification system 300 can be implemented in any physical environment or weather condition. FIG. 3 relates to incorporating a tuned resonant sensing material into an automotive component to classify signals (e.g., signatures) detected by and / or classified from and / or received from sensors installed in the vehicle. In operation 302, a ping signal at a selected ping frequency is transmitted. The ping signal generating mechanism and ping transmission mechanism can be implemented using any known technique. For example, a transmitter module can generate a selected frequency of 3 GHz and transmit the signal using one or multiple antennas. The design and location of the tuned antenna (such as mounted on and / or within any one or more of the wheel well or vehicle) can correspond to the geometry, material, and / or location of any tuned antenna such that the ping intensity is sufficient to induce resonance (RF) in the proximity sensor. Several tuned antennas are placed on or within the structural member in proximity to a corresponding sensor. In this way, the proximal surface sensor, when stimulated by a ping, can resonate and return with a signature. The signature is received (operation 304) and stored in a dataset, which may include the received signature 310. The sequence of transmitting pings followed by receiving the signature can be repeated in a loop.

[0077] The ping frequency may be changed during repeated passes through the loop (operation 308). Thus, when operation 304 is performed in a loop, operation 304 performs a first signature 3121, a second signature 3122, up to Nth signature 3123, and so on. NA signature 312 including the ping frequency may be stored. The number of iterations may be controlled by decision 306. When the "No" branch of decision 306 is taken (e.g., when there are no further pings to send), the received signature may be provided (at operation 314) to a digital signal processing module (e.g., an instance of the signature analysis module 254 shown in FIG. 2). The digital signal processing module classifies (at operation 316) the signature against a set of calibration points 318. The calibration points may be configured to correspond to specific ping frequencies. For example, the calibration points 318 may be any integer value "N" of calibration points (e.g., Nth calibration point 320). N up to 3 GHz), a first calibration point 3201 that can correspond to a first ping and first return signature near 3 GHz, a second calibration point 3202 that can correspond to a second ping and second return signature near 2 GHz, and so on.

[0078] In operation 320, the classified signals are sent to a vehicle central processing unit (e.g., vehicle central processing unit 116 of FIG. 1 ). The vehicle central processing unit 116 can relay the classified signals to an upstream repository that hosts a computerized database configured to host and / or execute machine learning algorithms. Thus, a vast amount of stimuli related to signals, classified signals, and signal responses can be captured for subsequent data aggregation and processing. The database may be computationally prepared, referred to as “training,” and provided with a given set of sensory measurements that can be correlated to conditions or diagnostics related to vehicle performance, such as tire degradation due to repeated use. During vehicle operation, if the measured deflection (e.g., air pressure) of a particular portion of the airfoil component differs from the measured deflection (e.g., air pressure) of a different portion of the airfoil component, a potential diagnosis could be that one tire is underinflated, causing uneven ground clearance for the vehicle, which could result in proportional unevenness in airflow over, over, and / or around the vehicle, as detected by deflections on the airfoil component. Other potential conditions or diagnoses can also be determined by the machine learning system. Condition and / or diagnostic and / or supporting data can be returned to the vehicle to complete the feedback loop. Instrumentation on the vehicle provides visualizations that can be performed (e.g., by the driver or engineer).

[0079] FIG. 4 illustrates a series of tire condition parameters sensed from changes in RF resonance of various layers of carbon-containing RF-tuned resonant material, according to one embodiment.

[0080] 4 illustrates a series of tire condition parameters 400 sensed from changes in RF resonance of various layers of a carbon-containing RF-tuned resonant material, according to one embodiment. Optionally, tire condition parameters 400 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that tire condition parameters 400 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0081] As shown, FIG. 4 illustrates various physical properties or aspects (tire condition parameters 400) associated with incorporating a tuned resonant sensing material into an automotive component (such as a tire). The drawings are presented herein with respect to addressing the deployment of survivable sensors in tires, including non-pneumatic and pneumatic tires. Tire configurations can correspond to radial tires, bias-ply tires, tubeless tires, solid tires, run-flat tires, and the like. These tires can be used on all types of vehicles and / or equipment and / or vehicle-related accessories. Such vehicles may include aircraft, all-terrain vehicles, automobiles, construction equipment, dump trucks, bulldozers, farm equipment, forklifts, golf carts, harvesters, lift trucks, mopeds, motorcycles, off-road vehicles, racing cars, lawn mowers, tractors, trailers, trucks, wheelchairs, and the like. These tires may also be used on non-motorized vehicles, equipment, and accessories, such as bicycles, tricycles, unicycles, lawn mowers, wheelchairs, carts, and the like, in addition to or instead of those presented.

[0082] The parameters shown in FIG. 4 are an example, and others may be present or otherwise tailored to target unique desired performance characteristics for many possible end-use scenarios, including a truck tire designed for extended life (possibly at the expense of road adhesion), or a soft racing tire designed for maximum road adhesion (possibly at the expense of road adhesion).

[0083] Various carbon structures can be used in different formulations with other non-carbon materials, incorporated into tires, and then subjected to mechanical analysis to determine their respective tire properties. Some of these properties can be determined empirically by direct testing, while others are determined based on measurements and extrapolation of data. For example, rolling uniformity can be determined by sensing changes in force as the tire rolls on a uniform surface such as a roller, while tread life is based on short-term abrasion tests, and the results of those short-term tests are extrapolated to arrive at a predicted tread life value.

[0084] Many more tire characteristics can be measured, but some of these measurement techniques can be physically destructive to the tire and therefore can be measured at desired points in the tire's life. In contrast, such destructive measurements can be performed throughout the tire's life using survivable sensors embedded in the tire. For example, RF-based response signal detection that pings sensors embedded in the tire can be used for such sensing. Moreover, each body ply and / or tread layer of the tire can include a durable (also referred to as "survivable") sensor tuned to resonate at a specific frequency, as described herein.

[0085] The plies used in a tire can be formulated to combine carbon-containing structures with other materials to achieve a specific material composition that exhibits desired performance characteristics (such as handling and lifespan). One natural resonant frequency (or multiple natural resonant frequencies) of a specific material composition can be subjected to spectral analysis to create a spectral profile for the specific material composition. This spectral profile can be used as a calibration baseline for that material. As the tire's body plies and / or tread layers undergo deformation, the spectral profile changes, and this change in spectral profile can be used as an additional calibration point (e.g., calibration point 318). Many such calibration points can be generated by testing, and these calibration points can then be used to measure deformation.

[0086] Analysis of the spectral response results in quantitative measurements of a number of tire parameters. Tire parameters that can be determined from the signature analysis include, for example, tread life 422, handling at first temperature 428, handling at second temperature 426, rolling economy at first temperature 430, rolling economy at second temperature 432, rolling uniformity 436, and braking uniformity 438.

[0087] The spectral response based on return ping signals received from sensors embedded in the material within the tire plies can represent the observed deformation. That is, a particular type of tire deformation corresponds to a specific type of unique response, and a mapping between these responses or response types can be made to degradation types. Furthermore, time-varying variations in the tire's spectral response as the tire deforms in situ can be used to determine many ambient conditions. In tires constructed using multiple plies, each body ply and / or tread layer can be formulated to exhibit a specific tuning frequency or a range of specific tuning frequencies. For example, FIG. 5 (shown below) illustrates a schematic diagram of a tire constructed from multiple plies, each ply having a different specific tuning frequency or range of specific tuning frequencies.

[0088] 5 illustrates a schematic diagram 500 of an apparatus used to tune multiple plies of a tire by selecting carbon-containing RF-tuned resonant materials from separate, independent reactors for incorporation into the body of a single tire assembly, according to one embodiment. Optionally, schematic diagram 500 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that schematic diagram 500 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0089] Schematic 500 can be implemented in any environment and can be used to fine-tune or tune multiple body plies and / or tread layers of a tire by selecting carbon-containing tuning resonant materials for incorporation into the tire assembly or structure. Figure 5 illustrates how different carbons can be mixed into tire composite formulations and integrated into multi-ply tires. The resulting multi-ply tires exhibit different resonant susceptibility and frequency shift characteristics.

[0090] Multiple reactors (e.g., reactor 5521, reactor 5522, reactor 5523, and reactor 5524) each produce (or otherwise transport or provide) a specific carbon additive / filter to a network that is tuned to produce a specific, defined spectral profile. The carbon additives (e.g., first tuned carbon 554, second tuned carbon 556, third tuned carbon 558, and fourth tuned carbon 560) can be mixed with other compositions 550 (carbon-based or non-carbon-based). Any known techniques can be used to mix, heat, pre-treat, post-treat, or otherwise combine the specific carbon additives with the other compositions. Agitators (e.g., agitator 5621, agitator 5622, agitator 5623, and agitator 5624) are presented to illustrate how different tuned carbons can be introduced into various components of a tire. Other techniques for tire assembly may include other construction techniques and / or other components that comprise the tire. Any known technique can be used for multi-ply tires. Additionally, the spectral profile of a particular body ply and / or tread layer (e.g., a group of body plies and / or tread layers 568, including body ply and / or tread layer 5681, body ply and / or tread layer 5682, body ply and / or tread layer 5683, and body ply and / or tread layer 5684) can be determined based on the characteristics of the particular body ply and / or tread layer formulation. For example, based on stimulus and response characteristics, a first body ply and / or tread layer formulation (e.g., body ply and / or tread layer formulation 5641) can exhibit a first spectral profile, while a second body ply and / or tread layer formulation (e.g., body ply and / or tread layer formulation 5642) can exhibit a second spectral profile.

[0091] The resulting various formulations (e.g., body ply and / or tread layer formulation 5641, body ply and / or tread layer formulation 5642, body ply and / or tread layer formulation 5643, and body ply and / or tread layer formulation 5644) are used in different body plies and / or tread layers formed in tire assembly 566, with each of these body plies and / or tread layers exhibiting a corresponding spectral profile.

[0092] 6 illustrates a set of exemplary condition signatures 600 that may be emitted from a new tire formed with a layer of carbon-containing RF-tuned resonant material, according to one embodiment. Optionally, the exemplary condition signatures 600 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that the exemplary condition signatures 600 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0093] FIG. 6 illustrates a second set of exemplary condition signatures 600 emanating from a tire formed with layers of carbon-containing tuned resonating material. The exemplary condition signatures 600, or any aspect thereof, can be emitted in any environment. FIG. 6 illustrates multiple body plies and / or tread layers (e.g., body ply and / or tread layer #1, body ply and / or tread layer #2, and body ply and / or tread layer #3) of a new tire. As used in this example and elsewhere with reference to any one or more of the presented embodiments, the term “ply” can refer to a ply or layer within the tire body, or alternatively, a tire tread layer that projects radially outwardly away from the tire body intended to contact hard pavement, or the ground for off-road tires. In one embodiment, a first body ply and / or tread layer can be compounded (meaning made by a specific compounding) with tuned carbon such that the first body ply and / or tread layer resonates at 1.0 GHz when stimulated with a 1.0 GHz ping stimulus (e.g., first ping 602). Similarly, the second body ply and / or tread layer is compounded with tuned carbon such that the second body ply and / or tread layer resonates at 2.0 GHz when stimulated with a 2.0 GHz ping stimulus (e.g., second ping 604). Additionally, the third body ply and / or tread layer is compounded with tuned carbon such that the third body ply and / or tread layer resonates at 3.0 GHz when stimulated with a 3.0 GHz ping stimulus (e.g., third ping 606). As shown by first response 608, second response 610, and third response 614, all three body plies and / or tread layers can respond at their respective tuned frequencies.

[0094] The transceiver antenna can be positioned within and / or on the wheel well of the corresponding tire (and / or in any location near the split ring resonator). A system that processes any response signal so generated can be configured to distinguish it from other potential responses originating from other surfaces, such as the remaining non-target tires of the vehicle. For example, even if a right front tire mounted on the right front wheel of a vehicle responds to a ping emitted from a transceiver antenna located in the vehicle's left front wheel well, the response signal from the right front tire will be significantly attenuated (and recognized as such) compared to the response signal from the vehicle's left front tire. In various embodiments, the positioning of the transceiver antenna can be within a few inches of the split ring resonator, or can be 5-10 meters (or even farther) as needed. Such positioning can be a function of the power of the emitter-receiver.

[0095] When the transceiver antenna is located within the wheel well of a corresponding tire, the response from the corresponding tire is attenuated to the ping stimulus. For example, the response from the corresponding tire may be attenuated by 9 decibels (-9 dB) or more to the ping stimulus, or by 18 decibels (-18 dB) or more to the ping stimulus, or by 36 decibels (-36 dB) or more to the ping stimulus, or by 72 decibels (-72 dB) or more to the ping stimulus. In some cases, the ping signal generator is designed to be combined with a transceiver antenna located within a wheel well such that the ping response of the corresponding tire is attenuated by a maximum of 75 dB (-75 dB) or less.

[0096] 7 illustrates a set of exemplary condition signatures 700 that may be emitted from a new tire formed with a layer of carbon-containing RF-tuned resonant material, according to one embodiment. Optionally, the exemplary condition signatures 700 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that the exemplary condition signatures 700 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0097] As shown, a third set of exemplary condition signatures 700 are emitted from a tire after wear of some carbon-containing tuned resonant material. Optionally, one or more variations of the exemplary condition signatures 700, or any aspect thereof, can be implemented in light of the architecture and functionality of the embodiments described herein. The exemplary condition signatures 700, or any aspect thereof, can be emitted in any environment.

[0098] In this example, the tire is worn. More specifically, the outermost body ply and / or tread layer is completely worn. As a result, a ping stimulus at 1.0 GHz resulted in no response from the outermost ply. This is shown in the chart as first response attenuation 702. As the tire tread continues to wear, the ping response from the next body ply and / or tread layer, the ping response from the next body ply and / or tread layer, and so on, attenuates, and this attenuation can be used to measure the total tread wear of the tire. Alternatively, the same tuning carbon can be used for all plies. Tire tread wear, as well as other indications, can be determined based on the signal signature returned from the tire.

[0099] 8 illustrates a top-down schematic diagram 800 of an exemplary split-ring resonator (split-ring resonator) arrangement including two concentric split-ring resonators, according to one embodiment. Optionally, top-down schematic diagram 800 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that top-down schematic diagram 800 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0100] As shown, FIG. 8 shows a top view of two layers, each hosting a split-ring resonator, forming an exemplary split-ring resonator arrangement including, for example, two concentric split-ring resonators. As used herein, a split-ring resonator consists of a pair of concentric rings arranged on a dielectric substrate, each ring having a slit (e.g., by a printed pattern). When an array of split-ring resonators is excited by a time-varying magnetic field, the structure behaves as an effective medium with a negative effective permeability within a narrow band around the resonance point of the split-ring resonators. Many geometries are possible, e.g., the dimensions and / or spacing between each split-ring resonator, including dimensions "a," "r," and / or "c," are selected to achieve a specific corresponding spectral response. For example, "a" may be approximately 1 mm, "r" may be 2 mm, and "c" may be approximately 0.6 mm. These dimensions may correspond to producing a desired and / or intended spectral response, for example, resulting in a relatively broad and / or wide signal response rather than a narrow and / or notched response, facilitating improved spectral analysis and increasing cost-effectiveness in using spectral analysis tools (e.g., spectrum analyzers). Additionally or alternatively, any dimension may be further adjusted to achieve a particular desired end result goal, such as for a race circuit application compared to an off-road application. In one embodiment, a particular geometry may include gaps between the concentric rings. Such gaps, combined with the inductance inherent in a pair of concentric rings, may create capacitance that changes the resonance of the ensemble.

[0101] Printable, sheet-oriented, cylindrical split ring resonator designs can be constructed from any conductive material, including metals, conductive nonmetals, dielectric materials, semiconductor materials, etc. In addition to tuning based on conductive material selection and / or processing, split ring resonators can be tuned by varying the geometry to tune the effective permittivity accordingly. The effective permittivity as a function of split ring resonator geometry is given by Equation 5:

number

[0102] In some situations, the value of a (e.g., the spacing between the cylinders of a cylindrical split-ring resonator) can be relatively small so that the concentric rings absorb EM radiation within a relatively narrow frequency range. In other situations, the value of a can be relatively large so that each of the concentric rings absorbs EM radiation at widely separated frequencies. In some situations, split-ring resonators of different sizes can be placed on different surfaces of the tire. In some situations, split-ring resonators of different sizes placed on different surfaces of the tire can be used to measure tire conditions (e.g., temperature, aging, wear, etc.).

[0103] In some embodiments, the material forming the split ring resonators is a composite material. Each split ring resonator can be configured to any particular desired tuned response to EM stimuli. At a minimum, the split ring resonators are designed to mimic the resonant response of atoms (but at much larger scales and lower frequencies), so the larger scale of the split ring resonators compared to atoms allows for more control over the resonant response. Furthermore, split ring resonators are much more responsive than ferromagnetic materials found in nature. The pronounced magnetic response of split ring resonators provides a significant advantage over heavier natural materials.

[0104] 9 shows a schematic diagram 900 illustrating a complete tire diagnostic system and apparatus for impedance-based spectroscopy tire wear sensing, according to one embodiment. Optionally, schematic diagram 900 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following diagram(s) and / or their description. However, it should be understood that schematic diagram 900 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0105] As shown, a schematic diagram 900 of a tire, such as a rubber pneumatic tire filled with air or nitrogen gas (N), can include conventional tire components including a body 920, an inner liner 912, a bead filler region 922, a bead 916, one or more belt plies 904, 906, 908, and 910, a tread 902, and impedance-based spectroscopy wear-sensing printed electronics 918 (alternatively, a sensor including carbon-based microstructures for monitoring frequency shift and attenuation of a signal by a resonator embedded within any one or more of the belt plies 904-910).

[0106] As shown herein, wireless strain sensors can be placed on the surface or on the side of (or embedded within) an innerliner to monitor tire condition for automotive safety (such as detecting damaged tires). Monitoring tire deformation or strain can (indirectly) provide information representative of the degree of friction between the tire and the road surface in contact, which can be used to optimize the vehicle's tire control system. Tire information can be wirelessly transmitted to a receiver positioned within the wheel well (and / or somewhere near the split-ring resonator) based on a resonant sensor platform. It should be understood that the receiver may be in any location that is potentially not opaque to high-frequency (wireless) signal transmission.

[0107] 10 illustrates a schematic diagram 1000 of tire information being transmitted via telemetry to a navigation system as well as to equipment for producing printed carbon-based materials, according to one embodiment. Optionally, schematic diagram 1000 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or description thereof. However, it should be understood that schematic diagram 1000 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0108] As shown, schematic diagram 1000 illustrates a system that provides tire-wear-related information that is transmitted via telemetry to a navigation system and equipment for manufacturing printed carbon-based materials. Because schematic diagram 1000 can function with any one or more of the systems, methods, and materials of the present disclosure, such as sensors including carbon-based microstructures, redundant descriptions of the same will be omitted. Impedance spectroscopy, also referred to as electrochemical impedance spectroscopy (EIS), refers to an impedance measurement transduction method that involves applying a sinusoidal electrochemical perturbation (potential or current) over a wide range of frequencies when measuring a sample, such as a sensor including carbon-based microstructures incorporated into one or more tire belt plies of a tire 1002. A printed carbon-based resonator 1004 can be incorporated into one or more tire components, such as the tire belt ply. Each of the printed carbon-based resonators 1004 may have the generally oval configuration shown, or some other shape or configuration that is tailored to achieve specific desired resonance characteristics suitable for efficiently and accurately detecting wear of vehicle components by monitoring frequency shift and / or damping (such as first response damping indicative of wear of a tire body ply and / or tread layer having a natural resonance frequency of approximately 1.0 GHz).

[0109] The roller assembly 1010, which can form the printed carbon-based resonator 1004, includes a reservoir 1012 (e.g., a vat) of carbon-based microstructures and / or microstructured materials (e.g., graphene), an anilox roller 1014 (which refers to a hard cylinder, typically constructed from a steel or aluminum core coated with an industrial ceramic (containing millions of very fine dimples on its surface), known as a cell), a printing cylinder 1016, and a pressed copper cylinder 1018. During operation, graphene extracted from the reservoir 1012 can be rolled, pressed, drawn, or otherwise fabricated into the printed carbon-based resonator 1004 by the rollers of the roller assembly 1010. Registration (referring to alignment) of the printed carbon-based resonator 1004 may not be necessary for the schematic 1000 to function.

[0110] As such, any combination of the aforementioned features can be used to fabricate a tire including a resonator (referring to an actual or "equivalent" tank), LC, and / or resonant circuit, where the carbon-containing microstructure itself can resonate in response to an RF signal emitted from a transceiver and / or energy provided by an advanced energy source, such that other sensors disposed within or on any one or more components of the tire, such as the tire tread, one or more plies, inner liner, etc., can exhibit frequency shift or signal attenuation characteristics or behaviors. The described resonators do not necessarily need to be embodied as actual electrical and / or integrated circuits (ICs). Because the described resonators can be easily realized as tuned carbon-containing microstructures, they avoid common degradation concerns that can arise when implementing conventional discrete circuits within degradable materials, such as tire tread layers. Such resonators may resonate in response to an externally supplied "ping" (such as provided by a transceiver located within the wheel well of the vehicle), or the resonators may respond to being charged by co-located (referring to within the same tire tread layer, but possibly at different locations within that tire tread layer), self-powered, self-pinging functionality facilitated by any variation or number of power or charge generators (e.g., thermoelectric generators, piezoelectric energy generators, triboelectric energy generators, etc.).

[0111] Any of the described resonators (and other resonators and / or resonant circuits) can emit and / or be configured to emit an oscillating RF signal (or other form of electromagnetic radiation, depending on the overall configuration) whenever the tire is rolling or otherwise deforming. When a vehicle tire undergoes wear due to use (such as on-road or off-road driving), the tire tread layer in contact with the pavement or ground (earth) can undergo deformation (such as from "crushing," which refers to at least partial flattening of sections of the vehicle tire tread layer exposed during rotation or rolling, and / or as observed from lateral motion, such as experienced during a turn) either instantaneously or over time, such that the frequency shift and / or attenuation behavior of the resulting signal can change in response to such "crushing," where the associated signal can oscillate over one or more known amplitude ranges. Additionally or alternatively, as the tire deforms, the observed signal may oscillate within a known frequency range corresponding to a particular resonator, thereby allowing for accurate and precise identification of the type of degradation occurring and allowing for tire tread condition to be observed while the vehicle is stationary, rather than requiring the driver, passengers, and / or other vehicle occupants to exit the vehicle. Such frequency-shifting oscillations may be observable as the frequency shifts back and forth between two or more frequencies within the known frequency range.

[0112] Wireless-enabled strain sensors (e.g., geometric measures of deformation representing relative displacement between particles within a body of material, which may be caused by external constraints or loads) positioned on the side of the innerliner can monitor tire condition for automotive safety (e.g., by detecting damaged tires). Additionally, monitoring tire deformation or strain can indirectly provide information related to the degree of friction between the tire and road surface, which can be used to optimize the vehicle's tire control system. Such tire information can be wirelessly transmitted to a receiver (and / or transceiver) positioned within the wheel hub based on a resonant sensor (e.g., impedance spectroscopy, IS, sensor) platform.

[0113] 11 illustrates a schematic diagram 1100 of tire information being transmitted via telemetry to a navigation system as well as to equipment for producing printed carbon-based materials, according to one embodiment. Optionally, schematic diagram 1100 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or description thereof. However, it should be understood that schematic diagram 1100 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0114] In one embodiment, diagram 1100 may relate to a resonant serial number-based digital encoding system for determining vehicle tire wear via ply print coding. The resonant serial number-based digital encoding system may be incorporated into and / or function in conjunction with any of the systems, methods, and sensors of the present disclosure. By providing a digital encoding of the tire via ply print coding, the resonant serial number-based digital encoding system provides cradle-to-grave tire tracking (and associated performance metrics) and usage profile without the need for traditional electronics that are subject to the everyday wear and tear on the tire.

[0115] Resonant serial number digital encoding of a tire by printing in the tire tread layer may, in some embodiments, facilitate tire tracking and use throughout without necessarily requiring the presence of electronics within the tire. For example, in addition to tire wear sensing achieved by impedance spectroscopy, additional resonators may be digitally encoded onto one or more printed patterns, such as a serial number used for telemetry tracking. As a result, vehicles so equipped can track tread wear, mileage (e.g., total mileage), and tire age without the need for radio frequency identification (RFID) technology.

[0116] In addition to tire wear sensing by impedance spectroscopy (IS) and / or electrochemical impedance spectroscopy (EIS), additional resonators can be digitally encoded onto the print pattern to provide a recognizable serial number for telemetry-based tire performance tracking. By sequentially printing onto the body ply and / or tread layer, tires incorporating the discussed printed carbon-based resonators can be given a unique serial number.

[0117] 12 illustrates a schematic diagram 1200 of a resonant serial number-based digital encoding of a vehicle tire by tire tread layer and / or tire body ply print encoding, according to one embodiment. Optionally, schematic diagram 1200 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or description thereof. However, it should be understood that schematic diagram 1200 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0118] As shown, it shows the serial number "6E" encoded within a specially prepared printed carbon resonator array, which is configured to resonate in accordance with a "ping" stimulus response diagram 1212, thereby allowing for easy and reliable identification of that particular body ply and / or tread layer of a vehicle tire so equipped.

[0119] 13 illustrates a resonant mechanism 1300 that contributes to an ensemble phenomenon resulting from different proximate resonator types, according to one embodiment. Optionally, resonant mechanism 1300 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that resonant mechanism 1300 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0120] In one embodiment, resonance mechanism 1300 may be used to illustrate the use of split ring resonators as resonating devices that contribute to ensemble phenomena resulting from different resonator types in close proximity. This diagram shows the inner surface 1301 of a tire, which has two split ring resonators (e.g., split ring resonator 1303A and split ring resonator 1303B), each forming a circuit arrangement 1305 that can be tuned to attenuate signals at a specific frequency and / or within a specific frequency range. In this embodiment, circuit arrangement 1305 is shown as a geometric pattern corresponding to a substantially circular split ring resonator, although alternative circuit arrangements can have different geometric patterns (e.g., cylindrical, elliptical, rectangular, oval, square, etc.), and as such, any conceivable geometric arrangement is possible. Geometric variations can be selected based on the effect of the geometric pattern on the resonant capabilities. In particular, as shown, the geometric pattern can include self-assembled carbon-based particles having various weak aggregation patterns (e.g., weak aggregation pattern 1306, weak aggregation pattern 1308, and weak aggregation pattern 1310), any one or more of which can constitute concentrated regions 1304 that can affect the resonant performance of a material in which the carbon-based microstructure is incorporated. A weak aggregation pattern and / or a series of weak aggregation patterns can also affect the resonant performance of a material in which the carbon-based microstructure is incorporated.

[0121] In various arrangements, the carbon-based microstructures may be formed at least in part by graphene. In this context, graphene may refer to an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice, with one atom forming each vertex. The collocation and / or juxtaposition of multiple such hexagonal lattices into more complex structures introduces additional resonance effects. For example, the juxtaposition 1302 of two sheets or platelets of graphene may resonate between themselves at a frequency that depends on the length, width, spacing, thickness, spacing geometry, and / or other physical properties of the sheets or platelets and / or their juxtaposition relative to one another.

[0122] Table 1 shows one possible code for damping resulting from ensemble effects. As shown in this table, each structure has a different resonant frequency range corresponding to its scale designation. [Table 1]

[0123] Any number of different split ring resonators can be printed on the surface of a tire. Additionally, any number of differently sized split ring resonators can be printed on either surface of a tire. Selection of the material and / or size and / or other structural or dimensional characteristics of a particular split ring resonator can be used to control the resonant frequency of the split rings of that particular resonator. A series of differently sized split ring resonators can be printed such that the pattern corresponds to a digitally encoded value. By stimulating a series of differently sized split ring resonators with electromagnetic signal communication, sweeping across a range, such as 8 GHz to 9 GHz, and measuring the decay response across the return range, a recognizable encoded serial number can be derived. Because many different encoding schemes are possible, the non-limiting examples in Table 2 are illustrative only. [Table 2]

[0124] 14 is an example temperature sensor 1400 including one or more of the split-ring resonators of the present disclosure, according to one embodiment. Optionally, the example temperature sensor 1400 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that the example temperature sensor 1400 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0125] In one embodiment, the exemplary temperature sensor 1400 may include a section 1402 of a tire body with multiple tire plies (e.g., as shown in FIG. 9 ). The exemplary temperature sensor 1400 may sense a temperature 1408 of the tire ply into which the exemplary temperature sensor 1400 is incorporated, for example. In one embodiment, the tire sensor may include a ceramic material 1404 (e.g., organized as a matrix) and one or more split ring resonators 1406, as shown in FIG. 8 and elsewhere in this disclosure. Each of the one or more split ring resonators 1406 may have a natural resonant frequency (e.g., as shown in FIG. 16 ), which may shift in response to one or more of a change in elastomeric properties or a change in temperature of the respective tire. A conductive layer 1410 may be dielectrically separated from each of the one or more split ring resonators 1406. In some embodiments, the example temperature sensor 1400 may be manufactured and shipped without being installed within a tire so that it can be later installed within a tire and / or tire ply.

[0126] In addition, or in an alternative embodiment, the exemplary temperature sensor 1400 may be incorporated into a system (not shown in FIG. 14 ) configured to sense strain in a tire of a vehicle (e.g., as shown in FIG. 16 ). The system may include an antenna (e.g., as discussed herein with respect to emitting and / or propagating electromagnetic signals) disposed on one or more of the vehicle or vehicle components. The antenna may be configured to output an electromagnetic ping sound. The system may also include a tire having a body (e.g., as shown in FIG. 9 ) formed from one or more tire plies. Any one or more of the tire plies may include split-ring resonators, for example, as described herein. In one embodiment, each split-ring resonator may have a natural resonant frequency configured to shift proportionally (e.g., as shown in FIG. 16 ) in response to changes in elastomeric properties, e.g., reversible deformation, stress, and / or strain, of the respective one or more tire plies.

[0127] In some implementations, the described systems may function to detect changes in physical properties of materials other than tires and / or components of vehicles (e.g., cars and trucks). For example, the system may detect changes in the surface temperature of airplane wings and / or other types of airfoils, such as those associated with spacecraft. The system may also obtain body temperature readings for individual patients without the use of traditional temperature sensors (e.g., via radiative heat transfer techniques), for example, by enabling one or more split-ring resonators 1406 to be removably adhered onto patients in a hospital. In any of these examples, as well as others, such systems may detect surface-related physical properties.

[0128] In one embodiment, the system may include a single antenna configured to output an electromagnetic ping sound and one or more flexible substrates. Each of the flexible substrates may include a first side including a plurality of split-ring resonators (split ring resonators) (e.g., one or more split ring resonators 1406, etc.) disposed on the flexible substrate. Each split ring resonator may have a natural resonant frequency that may shift proportionally (e.g., as shown in FIG. 16 ) in response to changes in the elastomeric properties of the respective one or more tire plies. The elastomeric properties may include one or more of reversible deformation, stress, strain, or temperature. In this manner, the system may generate an absorption profile (e.g., referring to a unique change in the absorption phenomenon of the electromagnetic ping sound output by the antenna). The system may include a second side positioned opposite the first side. The second side may be affixed to a surface. The single antenna may analyze data related to the absorption profile and output a topography of the physical property.

[0129] 15 is a graph 1500 of measured resonant signature signal strength (decibels, dB) versus tire tread layer loss height (millimeters, mm), according to one embodiment. Optionally, graph 1500 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that graph 1500 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0130] As shown herein, carbon-containing microstructures and / or microstructured materials can be incorporated into sensors, or in some configurations, into one or more entire tire tread layers at a given concentration level or at multiple different concentration levels (within each of one or more tire tread layers), to provide a unique degradation profile as shown. That is, a measured resonant signature (referring to a "signature" that identifies the particular tire tread layer in question) can be "pinged" by one or more RF signals as described herein, and can indicate attenuation of that emitted signal, as shown.

[0131] A new tire tread layer can be configured to exhibit a signal strength (measured in decibels, or dB) of approximately 0. The strength can vary proportionally to the degree of degradation of that tire tread layer. For example, a 2 mm height loss in a tire tread layer (assuming the tire tread layer is in contact with the pavement) can correspond to the measured resonant signature signal strength profile shown. A "ping" signal at 6.7 GHz can be measured at a similar strength level, such as approximately 9 dB or less.

[0132] Thus, unique concentration levels, chemistries, dispersions, distributions, and / or the like of carbon-containing microstructures can be embedded in a tire tread layer (or, in some cases, disposed on one or more surfaces thereof) to provide a unique and easily identifiable measured resonant signature signal strength, as shown. Thus, users of such systems can be instantly notified of the precise extent and location of tire tread wear occurring while driving, rather than being limited to observing the tire while the vehicle is stationary, a process that can be both time-consuming and labor-intensive.

[0133] 16 is a graph 1600 of measured resonant signature signal strength (in decibels, dB) versus natural resonant frequency of a split-ring resonator, illustrating a resonant response shift proportional to tire ply deformation, according to one embodiment. Optionally, graph 1600 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that graph 1600 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0134] In one embodiment, graph 1600 illustrates a measured resonant signature signal strength (in decibels, dB) versus a natural resonant frequency of split-ring resonator(s) (split-ring resonators) incorporated into a tire tread and / or tire ply (e.g., as discussed in this disclosure) according to one embodiment. As illustrated herein, carbon-containing and / or carbon-based microstructures and / or microstructured materials can be incorporated into a sensor, or, depending on the configuration, into one or more tire tread layers at a given concentration level or multiple different concentration levels (within each of one or more tire tread layers), to provide the unique degradation profile illustrated. That is, a measured resonant signature (referring to a "signature" identifying the particular tire tread layer in question) can exhibit a shift in its emitted signal when "pinged" by one or more RF signals, as described herein, that is representative of and / or proportional to the degree of reversible tire deformation, e.g., stress and / or strain (such as may be encountered in a drift scenario). In this way, the behavior of the split-ring resonator's "response" signal can be modeled as a function of tire deformation (such as strain) (related to drift), providing a complete picture of the tire's condition and performance. Real-world scenarios that cause loss of lateral tire stiction can include, for example, drifting and / or hydroplaning, which implies a phenomenon that occurs when a layer of water forms between a vehicle's wheels and the road surface, leading to a loss of traction and rendering the vehicle unable to respond to control inputs. If hydroplaning occurs simultaneously on all wheels in contact, the vehicle will effectively slide uncontrollably. Using the split-ring resonators and / or resonators of the present disclosure in combination with antennas and / or signal processing equipment can substantially eliminate reliance on conventional hydroplaning detection techniques, such as the use of vibration sensing units coupled to the tire's surface, which may deteriorate and become compromised over time. Furthermore, Figure 16 illustrates the spectral response (signal decibels) associated with lateral tire motion experienced during loss of stiction during drifting.In real-world scenarios, transient stiction losses, etc., may be audible by a high-pitched "screech" sound, as opposed to other sounds that are only audible during rapid forward turns. This type of periodic stiction loss (before the drifting vehicle regains stiction and / or traction) may manifest as periodic and / or periodic shifts in the natural resonant frequency of the corresponding split-ring resonator (not shown in FIG. 16). Furthermore, with respect to FIG. 16, a "screech" type situation may be visually depicted by slight periodic and / or periodic shifts in the frequency of the various troughs and / or peaks in the curve.

[0135] As can be seen, the real-time multi-modality resonator supports a method for measuring stiction using sensors containing a resonant material for detecting changes in elastomer properties. In one configuration, one or more sensors containing a resonant material for detecting changes in elastomer properties are positioned proximate to a transducer. A stimulus signal may be emitted to excite the one or more sensors containing a resonant material for detecting changes in elastomer properties. The emission includes electromagnetic energy over a known frequency range. A calibration signal is captured under known stiction conditions. After receiving a return signal that at least partially includes frequencies responsive to the stimulus signal, various signal processing techniques are applied to the return signal. For example, various signal processing techniques are applied to the return signal and compared with respect to the stimulus signal. Whenever the frequency and / or amplitude of the return signal differs from the calibration signal, a corresponding interfacial indirect permittivity is calculated (e.g., at the interface between the tire and the driving surface). The absolute and / or relative values ​​of the interfacial indirect permittivity are correlated to the stiction value (e.g., using a calibration table). Changes in the stiction value over time are correlated to road and / or tire conditions.

[0136] The static and / or dynamic values ​​comprising the calibration signals and / or calibration tables can be based at least in part on an analysis of the stimulus signal and / or an analysis of the environment proximate the transducer. Furthermore, the calibration signals and / or calibration tables can include permittivity calibration signals, permeability calibration signals, temperature calibration signals, vibration calibration signals, doping calibration signals, etc. In one embodiment, the calibration procedure can be performed under known and / or controlled environmental conditions, e.g., on dry pavement and during clear weather, to generate baseline data at various forward angular velocities (so that the test vehicle travels only forward, without skidding and / or sliding motion). This baseline data can serve as one or more calibration curves, from which deformation values ​​can then be compared and / or calculated. In this manner, a clear change in performance can be observed compared to an unstretched initial (baseline) calibration curve, as shown, for example, in FIG. 16 .

[0137] Whenever and wherever the return signal differs from the calibration signal, further analysis of the return signal relative to the stimulus signal can help identify which frequencies of the return signal differ from the calibration signal. These differences can be observed / measured as an attenuation of one or more frequencies relative to the calibration signal. Additionally, or alternatively, these differences can be observed / measured as a frequency shift of peaks relative to peaks of the calibration signal (such as shown in FIG. 16 for corresponding data scaled by 0.5%).

[0138] 17 is a graph 1700 of signal strength versus chirp signal frequency for a split-ring resonator that may resonate in response to an encoded serial number, according to one embodiment. Optionally, graph 1700 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that graph 1700 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0139] In one embodiment, graph 1700 illustrates the use of split-ring resonant structures configured to resonate in a manner corresponding to a coded serial number. A pattern of such split-ring resonant structures can be printed on a tire or other elastomer. As shown, the coded serial number "E1" is indicated by the presence of four differently sized split-ring resonators. Graph 1700 illustrates EM stimulation in the range of approximately 8 GHz to approximately 9 GHz, but response as attenuation in the range of approximately -8 dB to approximately -18 dB. By stimulating a series of differently sized split-ring resonators with electromagnetic signal communication across this range and measuring the returned S-parameters across this range, identification of the specific printed pattern is simple and reliable. Thus, if a unique pattern is printed on each successive tire, and if that pattern is associated with the coded serial number, then specific tire determination can be made based on the pattern's response to EM interrogation.

[0140] More specifically, if a unique pattern is printed on each successive tire and that pattern is associated with a coded serial number, then specific tire identification can be made based on S-parameters (e.g., S-parameter ratios corresponding to attenuation) measured in response to EM interrogation over a range of EM stimuli corresponding to the coding scheme. In the example of FIG. 17, the attenuation falls within a range of about −8 dB to about −18 dB, while in other measurements, the attenuation falls within a range of about −1 dB to about −9 dB. In other measurements, the attenuation falls within a range of about −10 dB to about −19 dB. In other measurements, the attenuation falls within a range of about −20 dB to about −35 dB. Empirical experiments have shown that attenuation is substantially independent of the number of resonators of different configurations positioned proximally on the tire surface. More specifically, some experiments have shown that attenuation can be particularly significant when the resonators are positioned proximally on the tire surface, which may be on the tread side of the steel belt (e.g., in a steel-belted radial tire).

[0141] The encoding and printing techniques described above can be used for tires and other elastomer-containing components. In some cases, printing the resonators is performed at relatively high temperatures and / or with chemicals (e.g., catalysts) to form chemical bonds between the carbon atoms of the resonators and the elastomer. Because the chemical bonds formed between the carbon atoms of the resonators and the elastomer contribute to the ensemble effect, a calibration curve can be created that takes into account the type and degree of such chemical bonds.

[0142] Elastomers may include any one or more types of rubber. For example, isoprene is a common rubber compound. Isoprene has its own C-C single bond and double bonds between other molecular elements within the ligand. The additional carbon-carbon double bonds formed by high-temperature printing of split-ring resonators have the effect of increasing electrical conductivity, which can be exploited to create larger, lower-frequency resonators. Additionally, or alternatively, weak aggregates can be tuned to specific sizes, resulting in overtones that contribute to ensemble effects, resulting in very high sensitivity for a given EM interrogation within the tuning range. In some cases, the material's response to EM interrogation is sufficiently distinct that the age of the elastomer or other aspects of its health can be determined (e.g., by comparison to one or more calibration curves).

[0143] More specifically, as elastomers age, molecular spacing changes, correspondingly reducing energy coupling and / or percolation, resulting in a shift in response frequency as conductive localities become more insulated from neighboring localities. In some cases, the attenuation and / or return signal strength at specific frequencies changes. These changes can be determined over time and used to generate calibration curves.

[0144] The tire design supports many possible locations for printing the split ring resonator. By way of example, the split ring resonator can be located on any interior surface of the tire, including but not limited to the cap ply, and / or on or near the steel belt (e.g., on the tread side of the steel belt), and / or on or near the radial ply, and / or on the sidewall, and / or on the bead chafer, and / or on the bead, etc.

[0145] The use of split ring resonator technology is not limited to tires. These technologies can be applied to any elastomer-containing component, such as belts and hoses. Furthermore, the use of split ring resonator technology is not limited to vehicles. That is, split ring resonator technology can also be applied to consumables, such as organic powertrain and / or drivetrain components, because such consumables exist in a wide range of power plants (e.g., in industrial mechanical systems). Some aspects of wear phenomena are the result of friction, heat, thermal cycling, and corrosion, any of which can cause and / or accelerate changes in the molecular structure of a material. Changes in the molecular structure of a material can be detected under EM interrogation. More specifically, by calculating the frequency shift, the response of a particular sample (e.g., the response of an aged sample) under a specific EM interrogation regime relative to a calibration curve, the age or health of the material, can be evaluated based on the magnitude of the frequency shift.

[0146] 18A-18Y illustrate carbon-based materials used as forming materials for fabricating any of the resonators (e.g., split-ring resonators) of the present disclosure, according to one embodiment. Optionally, FIGS. 18A-18Y may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their descriptions. However, it should be understood that FIGS. 18A-18Y may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0147] As shown, Figures 18A through 18Y illustrate carbon-based materials, growths, weak aggregates, strong aggregates, sheets, particles, and / or the like, such as those self-nucleated in-flight within a reaction chamber or reactor from carbon-containing gas phase species such as methane (CH4), as disclosed by Stowell, et al. in U.S. Patent Application No. 16 / 785,020, filed February 7, 2020, entitled "3D Self-Assembled Multi-Modal Carbon-Based Particle," the contents of which are hereby incorporated by reference for all purposes.

[0148] The carbon-based nanoparticles and aggregates described can be characterized by a high degree of "uniformity" (e.g., a high mass fraction of the desired carbon allotrope), a high degree of "order" (e.g., a low concentration of defects), and / or a high degree of "purity" (e.g., a low concentration of elemental impurities), in contrast to the less uniform, less ordered, and less pure particles achievable with conventional systems and methods.

[0149] The nanoparticles produced using the methods described herein can comprise multilayer spherical fullerenes (MWSFs) or combined MWSFs, and exhibit high uniformity (e.g., ratios of graphene to MWSFs between 20% and 80%), a high degree of order (e.g., I of 0.95 to 1.05), and a high degree of solubility (I of 0.95 to 1.05). D / I GThe nanoparticles produced using the methods described herein can have a high degree of purity (e.g., a Raman signature having a ratio of carbon to other elements (other than hydrogen) greater than 99.9%). The nanoparticles produced using the methods described herein comprise MWSFs or combined MWSFs, where the MWSFs do not include a core composed of impurity elements other than carbon. The particles produced using the methods described herein can be aggregates comprising the above nanoparticles having large diameters (e.g., greater than 10 μm).

[0150] While conventional methods have been used to produce particles containing highly ordered multilayered spherical fullerenes, they can lead to end products with various drawbacks. For example, high-temperature synthesis techniques result in particles containing a mixture of many carbon allotropes, resulting in low uniformity (e.g., less than 20% fullerenes relative to other carbon allotropes) and / or small particle sizes (e.g., less than 1 μm, or even less than 100 nm). Catalytic methods can also result in products containing catalytic elements, resulting in relatively low purity (less than 95% carbon relative to other elements). These undesirable properties often result in undesirable electrical properties (e.g., conductivity less than 1,000 S / m) in the resulting carbon particles.

[0151] The carbon nanoparticles and aggregates described herein can be characterized by Raman spectroscopy, which indicates a high degree of structural order and uniformity. The uniform, ordered, and / or pure carbon nanoparticles and aggregates described herein can be produced using improved thermal reactors and methods that are relatively fast and low cost, as described below.

[0152] The term "graphene," as commonly understood and as referred to herein, connotes a carbon allotrope in the form of a two-dimensional, atomic-scale, hexagonal lattice with one atom forming each vertex. The carbon atoms in graphene are arranged in a SP 2 Furthermore, graphene has a bond at approximately 1580 cm -1 G mode, approximately 1350cm -1The Raman spectrum has two main peaks: the D mode (when using a 532 nm excitation laser) at 1000 kHz and the D mode (when using a 532 nm excitation laser).

[0153] The term "fullerene," as commonly understood and as referred to herein, connotes a molecule of carbon in the form of a hollow sphere, ellipsoid, tube, or other shape. Spherical fullerenes may also be called buckminsterfullerenes or buckyballs. Cylindrical fullerenes are sometimes called carbon nanotubes. Fullerenes are structurally similar to graphite, consisting of stacked graphene sheets of linked six-membered rings. Fullerenes may also contain five-membered (or sometimes seven-membered) rings.

[0154] The term "multi-layer fullerene," as commonly understood and as referred to herein, connotes a fullerene having multiple concentric layers. For example, a multi-walled nanotube (MWNT) comprises multiple cylindrically rolled layers (concentric tubes) of graphene. A multi-walled spherical fullerene (MWSF) comprises multiple concentric spheres of fullerene.

[0155] The term "nanoparticle," as commonly understood and as referred to herein, connotes a particle having a size ranging from 1 nm to 989 nm. Nanoparticles can include one or more structural characteristics (e.g., crystalline structure, defect concentration, etc.) and one or more types of atoms. Nanoparticles can be any shape, including, but not limited to, spherical, ellipsoidal, dumbbell-shaped, cylindrical, elongated cylindrical, rectangular and / or prismatic, disk-shaped, wire-shaped, irregular, dense (e.g., less void), porous (e.g., more void), etc.

[0156] The term "aggregate," as commonly understood and as referred to herein, connotes a plurality of nanoparticles bound together by van der Waals forces, covalent bonds, ionic bonds, metallic bonds, or other physical or chemical interactions. The size of the aggregate can vary considerably but is generally greater than about 500 nm.

[0157] Carbon nanoparticles can include two (2) or more bonded multilayer spherical fullerenes (MWSFs) and a graphene layer coating the bonded MWSFs, and can be formed independently from a core composed of impurity elements other than carbon. As described herein, carbon nanoparticles can include two (2) or more bonded multilayer spherical fullerenes (MWSFs) and a graphene layer coating the bonded MWSFs. In such an arrangement, the MWSFs do not contain a void (referring to a space without carbon atoms larger than about 0.5 nm or larger than about 1 nm) in their center. The bonded MWSFs can be sp 2 -hybrid orbital carbon atoms (as opposed to conventional spheres of randomly ordered, non-uniform amorphous carbon particles, which may otherwise fail to achieve any one or more of the unexpectedly desirable properties disclosed herein).

[0158] The average diameter of the nanoparticles containing the conjugated MWSF is in the range of 5 to 500 nm, or 5 to 250 nm, or 5 to 100 nm, or 5 to 50 nm, or 10 to 500 nm, or 10 to 250 nm, or 10 to 100 nm, or 10 to 50 nm, or 40 to 500 nm, or 40 to 250 nm, or 40 to 100 nm, or 50 to 500 nm, or 50 to 250 nm, or 50 to 100 nm.

[0159] The carbon nanoparticles described herein form aggregates, where many nanoparticles join together to form larger units. The carbon aggregates can be multiple carbon nanoparticles. The overall diameter of the carbon aggregate can range from 10 to 500 μm, or 50 to 500 μm, or 100 to 500 μm, or 250 to 500 μm, or 10 to 250 μm, or 10 to 100 μm, or 10 to 50 μm. The aggregates can be formed from multiple carbon nanoparticles, as defined above. The aggregates can be highly uniform (e.g., graphene to MWSF ratios of 20% to 80%), highly ordered (e.g., I D / I G The Raman signature may include a combined MWSF, such as a Raman signature with a ratio of 0.95 to 1.05, and one that is highly pure (e.g., greater than 99.9% carbon).

[0160] Carbon nanoparticle aggregates, primarily those with diameters within the above range, particularly those greater than 10 μm, are generally easier to collect than particles smaller than 500 nm or aggregates. This ease of collection reduces the cost of the manufacturing equipment used to produce carbon nanoparticles and increases the yield of carbon nanoparticles. Particles greater than 10 μm in size also pose fewer safety concerns compared to the risks of handling small nanoparticles, such as the potential health and safety risks associated with inhaling small nanoparticles. Therefore, the reduced health and safety risks further reduce production costs.

[0161] The carbon nanoparticles disclosed herein may have a graphene to MWSF ratio of 10% to 90%, 10% to 80%, 10% to 60%, 10% to 40%, 10% to 20%, 20% to 40%, 20% to 90%, 40% to 90%, 60% to 90%, or 80% to 90%. The graphene to MWSF ratio of the carbon aggregates may be 10% to 90%, 10% to 80%, 10% to 60%, 10% to 40%, 10% to 20%, 20% to 40%, 20% to 90%, 40% to 90%, 60% to 90%, or 80% to 90%. The ratio of graphene in the carbon nanoparticles to the bonded MWSF is 10% to 90%, or 10% to 80%, or 10% to 60%, or 10% to 40%, or 10% to 20%, or 20% to 40%, or 20% to 90%, or 40% to 90%, or 60% to 90%, or 80% to 90%. The ratio of graphene in the carbon aggregates to the bonded MWSF is 10% to 90%, or 10% to 80%, or 10% to 60%, or 10% to 40%, or 10% to 20%, or 20% to 40%, or 20% to 90%, or 40% to 90%, or 60% to 90%, or 80% to 90%.

[0162] Raman spectroscopy can be used to characterize carbon allotropes to distinguish their molecular structures. For example, graphene can be characterized using Raman spectroscopy to determine information such as order / disorder, edges and grain boundaries, thickness, number of layers, doping, strain, and thermal conductivity. MWSFs have also been characterized using Raman spectroscopy to determine the degree of order in the MWSF.

[0163] Raman spectroscopy is used to characterize the structure of MWSFs or bonded MWSFs used with reference to those incorporated within various tire-related plies of a tire, as discussed herein. The dominant peaks in the Raman spectrum are the G mode and the D mode. The G mode is sp 2The D mode is due to vibrations of carbon atoms in the -orbital hybrid carbon network, and is associated with breathing of defective carbon hexagons. In some situations, defects may be present but not detectable in the Raman spectrum. For example, if the presented crystal structure is perpendicular to the basal plane, the D peak will increase. Alternatively, if a perfectly planar surface parallel to the basal plane is presented, the D peak will be zero.

[0164] When using 532 nm incident light, the Raman G mode is typically located at 1582 cm for planar graphite. -1 , but can be shifted down in the MWSF or combined MWSF (e.g., 1565 cm -1 or 1580cm -1 The D mode appears at approximately 1350 cm in the Raman spectrum of the MWSF or combined MWSFs. -1 The ratio of the intensity of the D-mode peak to the G-mode peak (e.g., I D / I G ) is related to the degree of order of the MWSF, and I D / I G A low I indicates a high degree of order. D / I G A value around or less than 1 indicates a relatively high degree of order, and I D / I G A value greater than 1.1 indicates a low degree of order.

[0165] As described herein, carbon nanoparticles or carbon aggregates containing MWSF or bound MWSF have a first Raman peak at about 1350 cm using incident light at 532 nm. -1 The second Raman peak is at approximately 1580 cm -1 The ratio of the intensity of the first Raman peak to the intensity of the second Raman peak (e.g., I D / I G) can be in the range of 0.95 to 1.05, or 0.9 to 1.1, or 0.8 to 1.2, or 0.9 to 1.2, or 0.8 to 1.1, or 0.5 to 1.5, or less than 1.5, or less than 1.2, or less than 1.1, or less than 1, or less than 0.95, or less than 0.9, or less than 0.8.

[0166] As defined above, the carbon aggregates comprising MWSF or bound MWSF have high purity. The carbon to metal ratio of the MWSF or bound MWSF carbon aggregates is greater than 99.99%, or greater than 99.95%, or greater than 99.9%, or greater than 99.8%, or greater than 99.5%, or greater than 99%. The carbon aggregates have a carbon to other element ratio of greater than 99.99%, or greater than 99.95%, or greater than 99.9%, or greater than 99.5%, or greater than 99%, or greater than 90%, or greater than 80%, or greater than 70%, or greater than 60%. In the carbon aggregate, the ratio of carbon to other elements (excluding hydrogen) is greater than 99.99%, or greater than 99.95%, or greater than 99.9%, or greater than 99.8%, or greater than 99.5%, or greater than 99%, or greater than 90%, or greater than 80%, or greater than 70%, or greater than 60%.

[0167] As defined above, carbon aggregates containing MWSF or combined MWSF have a high specific surface area. Carbon aggregates have a Brunauer, Emmett, and Teller (BET) specific surface area of ​​10 to 200 m 2 / g, or 10 to 100 m 2 / g, or 10-50m 2 / g, or 50-200m 2 / g, or 50-100m 2 / g, or 10 to 1000m 2 / g.

[0168] Carbon aggregates comprising MWSF or bonded MWSF, as defined above, have high electrical conductivity. Carbon aggregates comprising MWSF or bonded MWSF, as defined above, are compressed into pellets, and the conductivity of the pellets is greater than 500 S / m, or greater than 1,000 S / m, or greater than 2,000 S / m, or greater than 3,000 S / m, or greater than 4,000 S / m, or greater than 5,000 S / m, or greater than 10,000 S / m, or greater than 20,000 S / m, or greater than 30,000 S / m, or greater than 40,000 S / m, or greater than 50,000 S / m, or greater than 60,000 S / m, or greater than 70,000 S / m. 000 S / m, or between 500 S / m and 100,000 S / m, or between 500 S / m and 1,000 S / m, or between 500 S / m and 10,000 S / m, or between 500 S / m and 20,000 S / m, or between 500 S / m and 100,000 S / m, or between 1,000 S / m and 20,000 S / m, or between 10,000 S / m and 100,000 S / m, or between 10,000 S / m and 80,000 S / m, or between 500 S / m and 10,000 S / m. In some cases, the density of the pellets is about 1 g / cm 3 , or approximately 1.2 g / cm 3 , or about 1.5 g / cm 3 , or about 2 g / cm 3 , or approximately 2.2 g / cm 3 , or about 2.5 g / cm 3 , or about 3 g / cm 3 Additionally, tests were conducted in which compressed pellets of carbon aggregate material were formed at compressions of 2,000 psi and 12,000 psi with annealing temperatures of 800°C and 1,000°C. Higher compression and / or higher annealing temperatures generally resulted in pellets with higher electrical conductivity, including within the range of 12,410.0 S / m to 13,173.3 S / m.

[0169] The carbon nanoparticles and aggregates described herein can be produced using thermal reactors and methods. Further details regarding the thermal reactors and / or methods used can be found in U.S. Patent No. 9,862,602, entitled "CRACKING OF A PROCESS GAS," issued January 9, 2018, which is incorporated herein by reference in its entirety for all purposes. Additionally, thermal reactors can be used with carbon-containing and / or hydrocarbon precursors (referring to at least methane, ethane, propane, butane, and natural gas) to produce the carbon nanoparticles and carbon aggregates described herein.

[0170] The carbon nanoparticles and aggregates described herein are produced using a thermal reactor having a gas flow rate of 1 slm to 10 slm, or 0.1 slm to 20 slm, or 1 slm to 5 slm, or 5 slm to 10 slm, or greater than 1 slm, or greater than 5 slm. The carbon nanoparticles and aggregates described herein are produced using a thermal reactor having a gas resonance time of 0.1 seconds (s) to 30 s, or 0.1 s to 10 s, or 1 s to 10 s, or 1 s to 5 s, or 5 s to 10 s, or greater than 0.1 s, or greater than 1 s, or greater than 5 s, or less than 30 s.

[0171] The carbon nanoparticles and aggregates described herein can be produced using a thermal reactor having a production rate of 10 g / hr to 200 g / hr, or 30 g / hr to 200 g / hr, or 30 g / hr to 100 g / hr, or 30 g / hr to 60 g / hr, or 10 g / hr to 100 g / hr, or greater than 10 g / hr, or greater than 30 g / hr, or greater than 100 g / hr.

[0172] Thermal reactors (or other cracking devices) and thermal reactor processes (or other cracking processes) can be used to purify, pyrolyze, dissociate, or decompose raw process gases into their constituent parts to produce the carbon nanoparticles and carbon aggregates described herein, as well as other solid and / or gaseous products, such as hydrogen gas and / or less ordered hydrocarbon gases. The raw process gases are typically, for example, hydrogen gas (H 2 ), carbon dioxide (CO 2 ), C 1 ~C 10 The carbon nanoparticles and carbon aggregates may include, for example, multi-walled spherical fullerenes (MWSFs), bonded MWSFs, carbon nanospheres, graphene, graphite, highly ordered pyrolytic graphite, single-walled nanotubes, multi-walled nanotubes, other solid carbon products, and / or the carbon nanoparticles and carbon aggregates described herein.

[0173] The methods for producing carbon nanoparticles and carbon aggregates described herein can include pyrolysis methods, such as those using an elongated, longitudinal heating element optionally enclosed within an elongated casing, housing, or body of a pyrolyzer. The body can include one or more tubes or other suitable enclosures made of, for example, stainless steel, titanium, graphite, quartz, or the like. The pyrolyzer body is generally cylindrical, with a central, elongated, longitudinal axis oriented vertically, and a feedstock process gas inlet at or near the top of the body. The feedstock process gas can flow longitudinally downward through the body or a portion thereof. In a vertical configuration, both gas flow rate and gravity assist in the removal of solid products from the pyrolyzer body.

[0174] The heating elements may include any one or more of heat lamps, one or more resistive wires or filaments (or twisted wires), metal filaments, metal strips or rods, and / or other suitable thermal radical generators or elements capable of heating to a specific temperature (e.g., molecular decomposition temperature) sufficient to pyrolyze the molecules of the feed process gas. The heating elements may be disposed, located, or arranged within the body of the pyrolysis apparatus so as to extend centrally along its central longitudinal axis. In configurations with only one heating element, the heating element may be disposed on or concentrically disposed about the central longitudinal axis. Alternatively, in configurations with multiple heating elements, the heating elements may be disposed generally symmetrically, concentrically spaced, or offset in parallel positions near, around, and parallel to the central longitudinal axis.

[0175] Pyrolysis to produce the carbon nanoparticles and aggregates described herein can be accomplished by flowing a raw process gas over, in contact with, or near a heating element within a longitudinally elongated reaction zone generated by heat from a heating element and defined by and contained within the body of the pyrolysis apparatus, and heating the raw process gas to or at a specific molecular decomposition temperature.

[0176] The reaction zone can be considered to be the area surrounding the heating element and close enough to the heating element that the raw process gas receives sufficient heat to pyrolyze its molecules. Thus, the reaction zone is generally axially aligned or concentric with the central longitudinal axis of the body. Pyrolysis occurs under specific pressures. The raw process gas is circulated around or across the exterior of the reaction zone or heating chamber vessel, which cools and preheats the raw process gas before it enters the reaction zone.

[0177] The carbon nanoparticles and aggregates and / or hydrogen gas described herein are produced without the use of a catalyst, and therefore the process can be completely catalyst-free.

[0178] The disclosed methods and systems advantageously can be rapidly scaled up or down for different production levels as needed, such as providing a stand-alone hydrogen and / or carbon nanoparticle production station, hydrocarbon source, or fuel cell station, and being expandable to provide large capacity systems such as refineries and / or the like.

[0179] A pyrolysis apparatus for decomposing a feedstock process gas to produce the carbon nanoparticles and aggregates described herein includes a body, a feedstock process gas inlet, and an elongated heating element. The body has an interior volume about a longitudinal axis. The interior volume has a reaction zone concentric with the longitudinal axis. The feedstock process gas can flow into the interior volume through the feedstock process gas inlet during a pyrolysis operation. The elongated heating element can be disposed within the interior volume along the longitudinal axis and is surrounded by the reaction zone. During the pyrolysis operation, the elongated heating element is heated by electrical power to a molecular decomposition temperature to create the reaction zone, and the feedstock process gas is heated by heat from the elongated heating element, which pyrolyzes the molecules of the feedstock process gas into molecular constituents within the reaction zone.

[0180] The method for decomposing a raw process gas to produce carbon nanoparticles and aggregates described herein can include at least one of the following: (1) providing a pyrolysis apparatus having an interior volume having a longitudinal axis and an elongated heating element disposed within the interior volume along the longitudinal axis; (2) heating the elongated heating element with electrical power to a molecular decomposition temperature to create a longitudinally elongated reaction zone within the interior volume; (3) flowing the raw process gas into the interior volume and through the longitudinally elongated reaction zone (e.g., the raw process gas is heated by heat from the elongated heating element); and (4) pyrolyzing the raw process gas molecules within the longitudinally elongated reaction zone into their constituents (e.g., hydrogen gas and one or more solid products) as the raw process gas flows through the longitudinally elongated reaction zone.

[0181] The raw process gas used to produce the carbon nanoparticles and aggregates described herein can include hydrocarbon gases. Cracking results in the production of gaseous hydrogen (H 2 The carbon nanoparticles and aggregates may further include carbon nanoparticles and aggregates of various forms described herein. The carbon nanoparticles and aggregates may include two or more MWSFs and a graphene layer coating the MWSFs, and / or bonded MWSFs and a graphene layer coating the bonded MWSFs. The raw process gas is preheated (e.g., to 100°C to 500°C) by flowing the raw process gas through a gas preheating region between the heating chamber and the shell of the pyrolysis apparatus and then flowing the raw process gas into the interior volume. There, the nanoparticle-laden gas flows into the interior volume and mixes with the raw process gas through a longitudinally elongated reaction zone to form a coating of solid product (e.g., graphene layer) around the nanoparticles.

[0182] The carbon nanoparticles and aggregates comprising the multilayered spherical fullerenes (MWSFs) or bonded MWSFs described herein can be produced and collected without the need for any post-processing or manipulation. Alternatively, some post-processing can be performed on one or more of the MWSFs of the present disclosure. Some examples of post-processing relevant to the creation and use of resonant materials include mechanical treatments such as ball milling, pulverization, attrition milling, microfluidization, and other techniques that reduce particle size without damaging the MWSFs. Some further examples of post-processing include exfoliation processes (referring to the complete separation of layers of carbon-containing materials, such as the creation or extraction of graphene layers from graphite), which include shear mixing, chemical etching, oxidation (such as the Hummer process), thermal annealing, doping by adding elements (such as sulfur and / or nitrogen) during annealing, steam treatment, filtration, and freeze-drying. Some examples of post-processing include sintering processes, such as spark plasma sintering (SPS), direct current sintering, microwave sintering, and ultraviolet (UV) sintering, which can be performed at high pressures and temperatures in an inert gas. Multiple post-treatment methods can be used together or sequentially to produce functionalized carbon nanoparticles or aggregates containing multilayer spherical fullerenes (MWSFs) or bound MWSFs.

[0183] Materials can be mixed together in various combinations, amounts, and / or ratios. Different carbon nanoparticles and aggregates comprising MWSF or bonded MWSF described herein can be mixed together, if any, before one or more post-processing operations. For example, different carbon nanoparticles and aggregates comprising MWSF or bonded MWSF with different properties (e.g., different processing steps, different sizes, different compositions, different purity runs, etc.) can be mixed together. Carbon nanoparticles and aggregates comprising MWSF or bonded MWSF described herein can be mixed with graphene to vary the ratio of bonded MWSF to graphene in the mixture. Different carbon nanoparticles and aggregates comprising MWSF or bonded MWSF described herein can be mixed together after post-processing. Different carbon nanoparticles and aggregates comprising MWSF or bonded MWSF with different properties and / or different post-processing methods (different sizes, different compositions, different functionality, different surface properties, different surface areas, etc.) can be mixed together in any amount, ratio, and / or combination.

[0184] After the carbon nanoparticles and aggregates described herein are produced and collected, they are processed by mechanical comminution, grinding, and / or exfoliation. Processing (by mechanical comminution, grinding, exfoliation, etc.) can reduce the average particle size. Processing (by mechanical comminution, grinding, exfoliation, etc.) increases the average surface area of ​​the particles. Processing by mechanical comminution, grinding, and / or exfoliation shears off portions of the carbon layers, producing sheets of graphite that are mixed with the carbon nanoparticles.

[0185] Mechanical comminution or grinding can be accomplished using a ball mill, planetary mill, rod mill, shear mixer, high-shear granulator, autogenous mill, or other type of mechanical process used to break solid materials into smaller pieces by pulverizing, crushing, or cutting. Mechanical comminution, grinding, and / or scraping can be done wet or dry. Mechanical comminution can be accomplished by grinding for a period, idling for a period, and then repeating several cycles of grinding and idling. The grinding period can be 1 minute (min) to 20 min, or 1 min to 10 min, or 3 min to 8 min, or about 3 min, or about 8 min. The idling period can be 1 min to 10 min, or about 5 min, or about 6 min. The number of grinding and idling cycles can be 1 min to 100 min, or 5 min to 100 min, or 10 min to 100 min, or 5 min to 10 min, or 5 min to 20 min. The total time for grinding and idling is 10 minutes to 1,200 minutes, or 10 minutes to 600 minutes, or 10 minutes to 240 minutes, or 10 minutes to 120 minutes, or 100 minutes to 90 minutes, or 10 minutes to 60 minutes, or about 90 minutes.

[0186] The comminution step in a cycle is accomplished by rotating the mill in one direction (e.g., clockwise) for the first cycle and then rotating the mill in the opposite direction (e.g., counterclockwise) for the next cycle. Mechanical comminution or grinding is accomplished using a ball mill, with the comminution step being accomplished using a rotation speed of 100-1000 rpm, or 100-500 rpm, or about 400 rpm. Mechanical comminution or grinding is accomplished using a ball mill with grinding media having a diameter of 0.1 mm to 20 mm, or 0.1 mm to 10 mm, or 1 mm to 10 mm, or about 0.1 mm, or about 1 mm, or about 10 mm. Mechanical comminution or grinding is accomplished using a ball mill with grinding media composed of metals such as steel, oxides such as zirconium oxide (zirconia), yttria-stabilized zirconium oxide, silica, alumina, magnesium oxide, or other hard materials such as silicon carbide or tungsten carbide.

[0187] After the carbon nanoparticles and aggregates described herein are produced and collected, they can be processed using elevated temperatures, such as thermal annealing or sintering. The elevated temperature processing can be performed in an inert environment, such as nitrogen or argon. The elevated temperature processing can be performed at atmospheric pressure, under vacuum, or at reduced pressure. The elevated temperature processing can be performed at temperatures between 500°C and 2,500°C, or between 500°C and 1,500°C, or between 800°C and 1,500°C, or between 800°C and 1,200°C, or between 800°C and 1,000°C, or between 2,000°C and 2,400°C, or about 8,00°C, or about 1,000°C, or about 1,500°C, or about 2,000°C, or about 2,400°C.

[0188] After the carbon nanoparticles and aggregates described herein are produced and collected, the unique properties of the carbon nanoparticles and aggregates are incorporated into other material mixtures by adding additional elements or compounds to the carbon nanoparticles during post-processing operations.

[0189] Either before or after post-processing, the carbon nanoparticles and aggregates described herein can be added to solids, liquids, or slurries of other elements or compounds to form additional material mixtures that incorporate the unique properties of the carbon nanoparticles and aggregates. The carbon nanoparticles and aggregates described herein can be mixed with other solid particles, polymers, or other materials.

[0190] Either before or after post-processing, the carbon nanoparticles and aggregates described herein find use in a variety of applications beyond those related to the creation and use of resonant materials, including, but not limited to, transportation applications (auto and truck tires, couplings, mounts, elastomeric "o" rings, hoses, sealants, grommets, etc.) and industrial applications (rubber additives, polymeric functionalization additives, epoxy additives, etc.).

[0191] Figures 18A and 18B show transmission electron microscope (TEM) images of as-synthesized carbon nanoparticles. The carbon nanoparticles in Figure 18A (at a first magnification) and Figure 18B (at a second magnification) comprise bonded multilayer spherical fullerenes (MWSFs) with graphene layers, which coat the bonded MWSFs. In this example, the ratio of MWSFs to graphene allotropes is approximately 80% due to the relatively short resonance time. The MWSFs in Figure 18B are approximately 5 nm to 10 nm in diameter, which can be 5 nm to 500 nm using the conditions described above. The average diameter of the entire MWSF ranges from 5 nm to 500 nm, or 5 nm to 250 nm, or 5 nm to 100 nm, or 5 nm to 50 nm, or 10 nm to 500 nm, or 10 nm to 250 nm, or 10 nm to 100 nm, or 10 nm to 50 nm, or 40 nm to 500 nm, or 40 nm to 250 nm, or 40 nm to 100 nm, or 50 nm to 500 nm, or 50 nm to 250 nm, or 50 nm to 100 nm. Because no catalyst was used in this process, there are no central seeds containing contaminants. In this example, the aggregate particles produced had particle sizes of approximately 10 μm to 100 μm, or approximately 10 μm to 500 μm.

[0192] Figure 18C shows the Raman spectrum of the as-synthesized aggregates of this example taken with incident light at 532 nm. D / I G is approximately 0.99-1.03, indicating that the assembly is composed of highly ordered carbon allotropes.

[0193] Figures 18D and 18E show exemplary TEM images of carbon nanoparticles after size reduction by ball milling. Ball milling was performed in cycles of counterclockwise milling for 3 minutes (min), followed by idling for 6 minutes, followed by clockwise milling for 3 minutes, followed by idling for 6 minutes. The milling was performed at 400 rpm. The milling media was zirconia, and the size ranged from 0.1 mm to 10 mm. The total size reduction process time was 60 to 120 minutes. After size reduction, the aggregate particles produced in this example had a particle size of approximately 1 μm to 5 μm. The reduced carbon nanoparticles were bonded MWSFs with graphene layers, which coated the bonded MWSFs.

[0194] Figure 18F shows the Raman spectra from these aggregates after size reduction taken with incident light at 532 nm. In this example, the I D / I G The particle size after size reduction is about 40 m 2 / g~50m 2 / g Brunauer, Emmett and Teller (BET) specific surface area.

[0195] The purity of the aggregates produced in this sample was measured using mass spectrometry and X-ray fluorescence (XRF) spectroscopy. The ratio of carbon to other elements, excluding hydrogen, measured in 16 different batches ranged from 99.86% to 99.98%, with an average of 99.94% carbon.

[0196] In this example, carbon nanoparticles were produced using a thermal hot wire processing system. The precursor material was methane, flowing at 1 slm to 5 slm. With these flow rates and tool geometry, the resonant time of the gas in the reaction chamber was approximately 20 to 30 seconds, resulting in a carbon particle production rate of approximately 20 g / hr.

[0197] Further details regarding such processing systems can be found in the aforementioned U.S. Pat. No. 9,862,602, entitled "CRACKING OF A PROCESS GAS," which is hereby incorporated by reference for all purposes. [Example]

[0198] Figures 18G, 18H, and 18I show TEM images of the as-synthesized carbon nanoparticles of this example. The carbon nanoparticles comprise bonded multilayer spherical fullerenes (MWSFs) with graphene layers, which coat the bonded MWSFs. The ratio of multilayer fullerenes to graphene allotropes in this example is approximately 30% due to the relatively long resonance time, which allows for thicker or more graphene layers to coat the MWSFs. Because no catalyst was used in this process, there are no central seeds containing contaminants. In this example, the as-synthesized aggregate particles produced had particle sizes ranging from approximately 10 μm to 500 μm. Figure 18J shows the Raman spectrum from the aggregate of this example. The Raman signature of the as-synthesized particles in this example indicates thick graphene layers coating the MWSFs in the as-synthesized material. Furthermore, the as-synthesized particles have a diameter of approximately 90 μm. 2 / g~100m 2 / g Brunauer, Emmett and Teller (BET) specific surface area. [Example]

[0199] Figures 18K and 18L show TEM images of the carbon nanoparticles of this example. Specifically, these images show the carbon nanoparticles after size reduction by grinding in a ball mill. The size reduction process conditions were the same as those described above in connection with Figures 18G-18J. After size reduction, the particle size of the aggregate particles produced in this example was approximately 1 μm-5 μm. The TEM images show that the bound MWSF embedded in the graphene coating can be observed after size reduction. Figure 18M shows a Raman spectrum from the aggregate of this example after size reduction taken with incident light at 532 nm. The I for the aggregate particles in this example after size reduction D / I G is approximately 1, indicating that the bound MWSF, which was embedded in the graphene coating during synthesis, becomes detectable by Raman after size reduction and is well-ordered. 2 / g~100m 2 / g Brunauer, Emmett and Teller (BET) specific surface area. [Example]

[0200] Figure 18N is a scanning electron microscope (SEM) image of a carbon aggregate showing graphite and graphene allotropes at a first magnification. Figure 18O is an SEM image of a carbon aggregate showing graphite and graphene allotropes at a second magnification. Layered graphene is clearly visible within the wrinkles of the carbon. The 3D structure of the carbon allotropes is also visible.

[0201] The particle size distribution of the carbon particles of Figures 18N and 18O is shown in Figure 18P. The cumulative particle size distribution 1806 based on mass is plotted on the y-axis (Q 3 (x) [%]). The histogram of the mass particle size distribution 1808 corresponds to the axis on the right side of the graph (dQ 3 (x) [%]). The median particle size is approximately 33 μm. The 10th percentile particle size is approximately 9 μm, and the 90th percentile particle size is approximately 103 μm. The particle mass density is approximately 10 g / L. [Example]

[0202] The size distribution of carbon particles captured from the multi-stage reactor is shown in Figure 18Q. The cumulative particle size distribution 1814 based on mass is plotted on the y-axis (Q 3 (x) [%]). The histogram of the mass particle size distribution 1816 corresponds to the axis on the right side of the graph (dQ 3 The median particle size of the particles trapped is approximately 11 μm. The 10th percentile particle size is approximately 3.5 μm, and the 90th percentile particle size is approximately 21 μm. The graph in Figure 18Q also shows the y-axis (Q 0 18 shows the cumulative particle size distribution 1818 based on the number corresponding to the particle size distribution (x [%]). The median particle size based on the number is about 0.1 μm to about 0.2 μm.

[0203] Returning to the discussion of Figure 18P, the graph also shows the results of a second set of examples. Specifically, in these examples, particles were size reduced by mechanical comminution and then a cyclone separator was used to process the size-reduced particles. The cumulative particle size distribution 1810 based on the mass of the size-reduced carbon particles captured in this example is shown on the y-axis (Q 3 (x) [%]). The histogram of the particle size distribution 1812 based on mass corresponds to the axis on the right side of the graph (dQ 3 (x) [%]). In this example, the median particle size of the size-reduced carbon particles captured is approximately 6 μm. The 10th percentile particle size is between 1 μm and 2 μm, and the 90th percentile particle size is between 10 μm and 20 μm.

[0204] Further details regarding the manufacture and use of cyclone separators can be found in U.S. Patent Application No. 15 / 725,928, filed October 5, 2017, entitled "MICROWAVE REACTOR SYSTEM WITH GAS-SOLIDS SEPARATION," which is incorporated herein by reference in its entirety for all purposes.

[0205] In some cases, carbon particles and aggregates, including graphite, graphene, and amorphous carbon, can be produced using a microwave plasma reactor system with precursor materials, including methane, isopropyl alcohol (IPA), ethanol, or condensed hydrocarbons (e.g., hexane). In other examples, the carbon-containing precursor is optionally mixed with a feed gas (e.g., argon). The particles produced in this example include graphite, graphene, and amorphous carbon, and do not include seed particles. The ratio of carbon to other elements (other than hydrogen) in the particles in this example was greater than or equal to about 99.5%.

[0206] In one specific example, hydrocarbons were the input material of a microwave plasma reactor, and the separated output of the reactor included hydrogen gas and carbon particles, including graphite, graphene, and amorphous carbon. The carbon particles were separated from the hydrogen gas in a multi-stage gas-solid separation system. The solids loading of the separated output from the reactor was between 0.001 g / L and 2.5 g / L. [Example]

[0207] Figures 18R, 18S, and 18T are TEM images of as-synthesized carbon nanoparticles. These images show examples of graphite, graphene, and amorphous carbon allotropes. Layers of graphene and other carbon materials can be clearly seen in the images.

[0208] The size distribution of the trapped carbon particles is shown in Figure 18U. The cumulative size distribution 1820 based on mass is plotted on the y-axis (Q 3 (x) [%]). The histogram of the mass particle size distribution 1822 corresponds to the axis on the right side of the graph (dQ 3 (x) [%]). In this example, the median particle size captured by the cyclone separator was approximately 14 μm. The 10th percentile particle size was approximately 5 μm, and the 90th percentile particle size was approximately 28 μm. The graph in FIG. 18U also shows the particle size distribution on the y-axis (Q 018 shows the cumulative particle size distribution 1824 based on the number corresponding to the particle size distribution (x [%]). In this example, the median particle size based on the number was about 0.1 μm to about 0.2 μm.

[0209] Figures 18V, 18W, 18X, and 18Y are images showing three-dimensional carbon-containing structures grown on other three-dimensional structures. Figure 18V is a three-dimensional carbon structure grown on carbon fiber at 100X magnification, while Figure 18W is a three-dimensional carbon structure grown on carbon fiber at 200X magnification. Figure 18X is a three-dimensional carbon structure grown on carbon fiber at 1601X magnification. Three-dimensional carbon grown on the fiber surface is shown. Figure 18Y is a three-dimensional carbon structure grown on carbon fiber at 10,000X magnification. This image shows growth not only on the basal plane, but also on the edge planes.

[0210] More specifically, Figures 18V-18Y show exemplary SEM images of 3D carbon material grown on fibers using not only plasma energy from a microwave plasma reactor but also thermal energy from a thermal reactor. Figure 18V shows an SEM image of fiber 1831 and fiber 1832 intersecting, with 3D carbon material 1830 grown on the surfaces of these fibers. Figure 18W is a higher magnification image (scale bar is 300 μm compared to 500 μm in Figure 18V) showing 3D carbon material 1830 on fiber 1832. Figure 18X is an even more enlarged view (scale bar is 40 μm) showing 3D carbon material 1830 on fiber surface 1835, where the 3D nature of 3D carbon material 1830 can be clearly seen. Figure 18Y shows a close-up view of the carbon alone (scale bar is 500 nm), showing the interconnections between the basal surface 1832 of the fiber and the edge surfaces 1834 of the numerous sub-particles of 3D carbon material grown on this fiber. Figures 18V-18Y demonstrate the ability to grow 3D carbon on 3D fibrous structures, such as 3D carbon grown on 3D carbon fibers.

[0211] Growth of 3D carbon on fibers can be achieved by introducing multiple fibers into a microwave plasma reactor and etching the fibers using the plasma within the reactor. The etching creates nucleation sites, which initiate the growth of 3D carbon structures as carbon particles and subparticles are created by hydrocarbon dissociation within the reactor. Direct growth of 3D carbon structures on these fibers, which are essentially three-dimensional, results in highly integrated 3D structures containing pores through which the resin can penetrate. This 3D reinforcing matrix for resin composites (containing 3D carbon structures integrated with high-aspect ratio reinforcing fibers) results in improved material properties, such as tensile strength and shear, compared to composites containing conventional fibers with smooth surfaces, which typically delaminate from the resin matrix at these smooth surfaces.

[0212] Carbon materials, such as any one or more of the 3D carbon materials described herein, can have one or more exposed surfaces prepared for functionalization, such as to promote adhesion and / or add elements such as oxygen, nitrogen, carbon, silicon, or curing agents. Functionalization refers to the addition of functional groups to a compound through chemical synthesis. In materials science, functionalization can be used to achieve desired surface properties; for example, functional groups can be used to covalently attach functional molecules to the surface of a chemical device. Carbon materials can be functionalized in situ, i.e., in the same reactor where the carbon material is produced. Carbon materials can also be functionalized during post-processing. For example, the surface of fullerenes or graphene can be functionalized with oxygen- or nitrogen-containing species that form bonds with the polymer of a resin matrix, thus improving adhesion and providing strong bonds to increase the strength of the composite.

[0213] A functionalization surface treatment can be performed on any one or more of the carbon-based materials of the present disclosure (e.g., CNTs, CNO, graphene, 3D carbon materials such as 3D graphene) utilizing a plasma reactor (e.g., microwave plasma reactor) described herein. Such treatments can include in situ surface treatments during fabrication of the carbon material, which can be combined with a binder or polymer in a composite, or post-fabrication surface treatments of the carbon material while it is still in the reactor.

[0214] Some of the aforementioned embodiments include a resonator containing a plurality of three-dimensional (3D) strong assemblies formed from a carbon-containing material embedded within one or more plies of a tire. However, some embodiments include a resonator printed or otherwise disposed on an interior surface of the tire (e.g., an inner liner of the tire).

[0215] FIG. 19A1 provides a representation 19A100 of a split-ring resonator or multiple split-ring resonators placed in concrete before the concrete is poured into a given structural form, according to one embodiment. Optionally, representation 19A100 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 19A100 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0216] As shown in Figure 19A1, split ring resonators can be incorporated into a concrete pour 1902. A split ring resonator or split ring resonators 1904 can be mixed into the concrete 1906 while in the mixing vessel, or a split ring resonator or split ring resonators can be mixed into the concrete while the concrete is in the pouring process.

[0217] A split ring resonator or split ring resonators 1904 can be trapped in the concrete pour 1902. The split ring resonators can be trapped in the formwork in any orientation, but may be deposited near the bottom of the structural element. For example, any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is substantially vertical, or any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is substantially horizontal, or any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is at an angle between the vertical and horizontal directions.

[0218] In certain situations, the split-ring resonator is trapped within the formwork at a location relatively proximal to the formwork boundary. In other cases, the split-ring resonator enters the formwork at a location relatively distal to the formwork boundary. This is due to the natural tendency (e.g., fluid dynamics) of foreign objects (e.g., split-ring resonators) to be randomly located within the concrete pour 1902. The technique for pinging the split-ring resonator with a signal and receiving a return signal is operational regardless of the split-ring resonator's location within the formwork. More specifically, because the signal-to-noise ratio is very wide (see the 18 dB separation shown in FIG. 17), being able to receive and process the return signal from any given split-ring resonator at any particular location can facilitate comparison to a calibration signal. This technique can be applied to a variety of structures. One such example can be seen in FIG. 19A1, which shows a vertically oriented concrete structural member.

[0219] While the above examples relate to vertically oriented concrete structural members, the techniques disclosed herein also apply to forming horizontally oriented concrete structural members (or concrete structural members at any angle).

[0220] FIG. 19A2 provides a representation 19A200 of a split-ring resonator or multiple split-ring resonators placed in concrete before the concrete is poured into a given structural form, according to one embodiment. Optionally, representation 19A200 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 19A200 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0221] In one embodiment, Figure 19A2 shows a split ring resonator or multiple split ring resonators 1904 that can be incorporated onto the concrete pour 1902 as it is poured into the slab 1910. The split ring resonator or multiple split ring resonators 1904 can be mixed into the concrete 1906 while it is in the mixing vessel, or the split ring resonator or multiple split ring resonators 1904 can be mixed into the concrete 1906 while the concrete is partway through the pouring process.

[0222] The split ring resonator or resonators 1904 can be captured within the concrete pour 1902 and within the formwork in any orientation. For example, any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is substantially vertical, or any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is substantially horizontal, or any given split ring resonator can be oriented such that the normal vector from the plane of the split ring resonator is at an angle between the vertical and horizontal directions. The split ring resonator or resonators 1904 may, in one embodiment, be distributed closer to the wall of the horizontally oriented concrete structural member 1914. In certain embodiments, the split ring resonator or resonators 1904 may be positioned within the formwork in a position relatively close to the top surface of the horizontally oriented concrete structural member 1914. In certain other embodiments, the split ring resonator or resonators 1904 may be relatively close to the bottom surface of the horizontally oriented concrete structural member 1914. Nevertheless, the split ring resonator or resonators 1904 may be oriented to, integrated with, and / or affixed to a rebar (or other supporting structure within the concrete member) such that the position of the split ring resonator or resonators 1904 may be maintained during concrete pouring 1902 into the concrete member.

[0223] In various embodiments, FIGS. 19A1 and 19A2 illustrate an embodiment of a split-ring resonator or multiple split-ring resonators placed in concrete before the concrete is poured into a given structural form (e.g., a vertically oriented concrete structural member, a horizontally oriented concrete structural member). Furthermore, FIGS. 19A1 and 19A2 are presented to illustrate how, in one embodiment, a split-ring resonator (e.g., a ring or cylindrical one) or multiple split-ring resonators 1904 (e.g., ring or cylindrical, or a combination thereof) can be incorporated into the concrete mix before pouring the concrete into the form. The form can be of any shape. Strictly by way of example, as shown in FIG. 19A1 , the form can be configured to receive the pouring of a vertically oriented concrete structural member 1912 (e.g., the illustrated column or wall 1908). Additionally or alternatively, as shown in FIG. 19A2, the form can be configured to receive the pouring of horizontally oriented concrete structural members 1914 (eg, the illustrated slab 1910).

[0224] The technique for pinging the split ring resonator with a signal and receiving a return signal may remain operational regardless of the split ring resonator's location within the formwork (e.g., on the top, bottom, in the concrete, etc.). More specifically, because the signal-to-noise ratio is very wide (see the 18 dB separation shown in FIG. 17), being able to receive and process the return signal from any given split ring resonator in any particular location may facilitate comparison with an earlier captured calibration signal.

[0225] In one embodiment, the aforementioned calibration signal may be captured after pouring and curing. Such calibration signal may be stored in a database and / or any system that retains designated information. At a later time, the structural member may be interrogated for a ping signal, and the return signal at that time may be compared to the corresponding calibration signal. In one embodiment, a difference between the later captured signal and the calibration signal may indicate a change in compression between the time the calibration signal was captured and the time the interrogation is performed.

[0226] A similar approach can be applied in the presence of multiple split-ring resonators distributed throughout a structural member. Specifically, a ping signal is sent into a region of the structural member where many split-ring resonators are present in substantially the same location, and a calibration signal is returned and can be stored in a database or any other system capable of storing information. At some later point in time, the structural member can be interrogated again with a ping signal, and the returned signal at that time can be compared with the corresponding calibration signal. If a difference between the two signals is determined, this phenomenon can indicate a change in the structure and / or its constituent materials. There are many possible techniques for analyzing changes in response (e.g., due to compression or bending), some of which are shown and described in connection with FIG. 19B1.

[0227] FIG. 19B1 shows a representation 19B00 of a post including a split-ring resonator or multiple split-ring resonators and an equation for measuring changes in a structural member, according to one embodiment. Optionally, representation 19B00 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 19B00 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply to the following description as well.

[0228] As shown, depiction 19B00 illustrates various equations for measuring changes within a cured column including a split ring resonator or multiple split ring resonators 1904 and a structural member. Additionally, a change 1916 in compression of the material surrounding the split ring resonator 1904 initiates a change 1922 in response from the split ring resonator (as shown in FIG. 19B2). Furthermore, FIG. 19B1 illustrates an example of Equation 6 for measuring the degree of compression (as a function of change in compression) within a structural member. Additionally, while Equation 6 is illustrated with respect to compression, Equation 7 (hereinafter) is illustrated with respect to change in response, and it should be understood that any change in torsion, hygroscopicity (humidity), bending, response, material properties, etc., can be the basis for determining and / or measuring changes in the split ring resonator(s).

[0229] In one embodiment, a use model may support the structural assessment of infrastructure concrete foundations (e.g., apartment buildings, condominiums, homes, hotels). Additionally, a use model may support the structural assessment of building infrastructure in general, including monitoring steel beams, columns / pillars, and other aspects of structural health monitoring. Continuous or periodic monitoring of material integrity over time can indicate whether the materials forming a structure have changed, for example, due to aging, excessive or related stress, and / or physical damage. In some cases, it may be possible to prevent imminent material failure and avert catastrophic events. In some situations, multiple structural members may be combined into a load-bearing structure, and the entire load-bearing structure needs to be monitored over time. Calibration and periodic monitoring may be accomplished, for example, in two steps. In the first step, a technician operates a signal generator (or similar tool) and tunes the signal generator to a selected frequency to emit a signal proximate to a split-ring resonator within the structural member. The return signal and / or its characteristics (e.g., damping, single frequency resonance, multiple frequency resonance, etc.) from the split ring resonator is captured. The technician stores the return signal and / or its characteristics as a calibration point associated with that location and that ping at that given time. The return signal and / or its characteristics are later used as a calibration signature corresponding to the time at which the material is considered to have a baseline state of structural integrity.

[0230] In a second step, performed at some later time after the first step, the technician may repeat the pinging and signature capture process to collect current data returned by the split ring resonators within the structural member. A comparison between the calibration signature and the current data may indicate a change in material integrity. In one embodiment, the change in response 1918 may only indicate a change in compression. A range of changes in compression over time may be considered normal and may occur during normal use (e.g., when a structure flexes under stress due to tectonic activity such as an earthquake). In addition to the aforementioned techniques for measuring changes in compression, further techniques are presented herein relating to measuring changes in bending.

[0231] FIG. 19B2 shows a representation 19B02 of a post including a split-ring resonator or multiple split-ring resonators and an equation for measuring changes in a structural member, according to one embodiment. Optionally, representation 19B02 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 19B02 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply to the following description as well.

[0232] In one embodiment, depiction 19B02 shows a cured slab including a split ring resonator or multiple split ring resonators 1904 and exemplary Equation 7 for measuring the degree of bending in the structural member (as a function of change in stiffness). Additionally, changes in bending 1920 in the material surrounding the split ring resonator 1904 cause changes in response 1922 from the split ring resonator, resulting in a signal response that differs from that originally determined. This information is considered essential for monitoring the integrity of the material in that application.

[0233] In a given case, as described above, a split ring resonator or multiple split ring resonators 1904 are implemented within a concrete foundation to enable monitoring of the material. This may be accomplished, by way of example, in two steps. In the first step, a technician operates a signal generator (or similar tool) and tunes the signal generator to a selected frequency, causing the signal generator to emit a signal proximate to the split ring resonators within the structural member. A return signal and / or its characteristics (e.g., attenuation, single frequency resonance, multiple frequency resonance, etc.) from the split ring resonator are captured. The technician stores the return signal and / or its characteristics as a calibration point associated with that location and the ping at that given time. The return signal and / or its characteristics are later used as a calibration signature corresponding to a point in time at which the material is considered to have a baseline state of structural integrity.

[0234] When implementing one or more split-ring resonators within a member, precise orientation and positioning may not be controllable during pouring, but the two-step procedure described above can still be used. This is because when pinging multiple split-ring resonators, the ensemble effect signal (return from the multiple split-ring resonators) can be used as a calibration. In a second step, performed at some later time after the first step, the technician again repeats the pinging and signature capture process to collect current data returned by the split-ring resonators within the structural member. A comparison between the calibration signature and the current data may indicate a change in material integrity. On the other hand, a change in response 1918 may merely indicate a change in compression. A certain range of change in compression over time may be considered normal and may occur during normal use (e.g., when a structure bends under stress due to tectonic movements such as an earthquake). In addition to the aforementioned techniques for measuring changes in compression, further techniques are presented herein for measuring changes in bending.

[0235] If a structural member is already in a given use, a split ring resonator or multiple split ring resonators 1904 can still be implemented on the structural member, regardless of its physical properties (e.g., shape, size, location), examples of which are shown and described in connection with FIG.

[0236] 20 illustrates the use 2000 of split-ring resonators externally on structural members of various shapes, already in use, according to one embodiment. Optionally, use 2000 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that use 2000 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0237] In one embodiment, Figure 20 also illustrates examples of possible factors and equations that may be important in determining the size, orientation, location, and application of one or more split ring resonators on a structural member. Additionally, Figure 20 illustrates the use of split ring resonators applied externally to structural members of various shapes. Figure 20 illustrates examples of possible factors and equations that may be important in determining the size, orientation, location, and application of one or more split ring resonators on a structural member.

[0238] 20 shows a horizontal member 2002 to which a split ring resonator 1904 can be attached (e.g., using ultrasonic welding) and used for a given application (e.g., axle components, tie rod components, push rods, rebar, etc.) In addition to horizontal elongated members, split ring resonators may also be attached to curved members 2004 (e.g., bucket handles, suspension components, sections of springs, rebar, etc.).

[0239] In one particular case, a split-ring resonator 1904 or multiple spaced-apart split-ring resonators can be applied to rebar using any known technique, and the rebar may then be placed into a form. When concrete or other construction composition is poured into the form, the juxtaposition of the split-ring resonators on the rebar and within the form remains substantially the same as when the split-ring resonators were applied to the rebar and placed within the form. In this manner, the split-ring resonators can be positioned to be substantially aligned in a horizontally oriented plane (i.e., in the "X" direction), or substantially aligned in a vertically oriented plane (i.e., in the "Y" direction), or substantially aligned in a depth-oriented plane (i.e., in the "Z" direction).

[0240] Additionally or alternatively, split ring resonators may be attached to a flat structural member 2006 (e.g., a car hood). In this given application, the split ring resonators may be used to measure the bending of the car hood dynamically and at any instant in time. This method offers many advantages over using a wind tunnel to measure the bending of the car hood, since in the case of a wind tunnel, the vehicle is stationary, whereas in the contemplated use model, the vehicle is actually moving, and an actual real-time response can be calculated. Thus, one or more split ring resonators 1904 provide immediate feedback during actual driving conditions.

[0241] The determined size of the split-ring resonator(s) per structural member can depend not only on the size of the member but also on the application. This is shown in Equation 8. Specifically, split-ring resonators of different sizes will resonate at correspondingly different frequencies. The different sizes can be taken into account during initial calibration testing.

[0242] In certain situations (e.g., when applying split-ring resonators to straight horizontal members, or when applying split-ring resonators to curved members, or when applying split-ring resonators to flat members), the optimal position (Equation 10) and / or orientation (Equation 9) can be determined or inferred from analysis of a finite element model (e.g., using CAD software such as SOLIDWORKS, AGROS2D, CALCILIX, etc.). More specifically, the finite element analysis results in bending, compression, and expansion vectors depending on the application and desired properties of interest. Based on the results from the finite element analysis, a particular structural member can be configured with split-ring resonators in the corresponding position (Equation 10) and / or orientation (Equation 9).

[0243] 21 is a flowchart 2100 illustrating a process by which a split-ring resonator may be implemented for a given application, according to one embodiment. Optionally, flowchart 2100 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that flowchart 2100 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0244] As shown, the first step in the process is to determine whether the scenario allows for either internal or external placement of split ring resonators (step 2102). For internal applications of one or more split ring resonators (step 2104), a mix-in technique must be determined (step 2106). In one embodiment, one or more split ring resonators may be combined with an aggregate mixture or cement. The aggregate mixture or cement may then be poured into a structure or foundation, with the split ring resonators randomly dispersed throughout the mixture to ultimately form the component (step 2110).

[0245] Once the foundation or structure has cured, the split ring resonators can be calibrated and an initial state or calibration signature can be collected (step 2114). To achieve the calibration signature, a unique signal can be used to ping the response from the split ring resonators. Based on the properties of the medium in which the split ring resonators are immersed, a response can be generated as a function of the medium's parameters (e.g., compaction, density, frequency, etc.). This initial reading when the structure is in some initial state can become the calibration signature and reference parameters for future comparison. Of course, it should be understood that the initial reading can be reset (and / or recalibrated) at a later point in time (e.g., after cement pouring, seismic retrofitting, etc.).

[0246] For external applications (e.g., by ultrasonic welding), one or more split-ring resonators are integrated onto a component in a manner that does not compromise the accuracy of the split-ring resonators. The orientation, position, and application of the split-ring resonators can be used to collect correct data from the split-ring resonators (step 2108) (e.g., installing the split-ring resonators on an automobile axle). The orientation of the split-ring resonators relative to the axle can be used to achieve normal, horizontal, or angled vectors from the plane of the split-ring resonators, allowing for steerable return of the calibration signature or calibration points without compromising the signal-to-noise ratio. The location of the split-ring resonators on the axle can be positioned within the zones of failure and partial reversal stress for proper monitoring of the axle's integrity. Ultrasonic welding of the split-ring resonators to the axle (step 2112) can be used to ensure the accuracy of the split-ring resonator's calibration signature and calibration points. Sonic welding allows dissimilar materials to be joined without using solder or other materials to form a weld that may attenuate or alter the response of the split ring resonator, although it should be understood that any type of adhesive may be used in place of a weld.

[0247] As shown in the flowchart, both the external and internal processes converge on a test event (step 2116). During the test event, a stimulus is applied (step 2118) and a response is measured (step 2120). The test event is used to collect calibration points and compare them to the calibration signature (step 2122). The test is performed after a given time has passed, strictly for example, after a stress event occurs on the structure or component, or after a test is required due to routine maintenance or visual observation of the component or structure. This test returns calibration points that may be similar in nature to the calibration signature obtained later when the structure or component may differ in structural integrity. Obtaining the required calibration may be accomplished using a two-step technique. In the first step (step 2120), a technician operates a signal generator (or similar tool) and tunes the signal generator to a selected frequency to emit a signal proximate to the split-ring resonator within the structural member. The return signal and / or its characteristics (e.g., damping, single frequency resonance, multiple frequency resonance, etc.) from the split ring resonator is captured. The technician stores the return signal and / or its characteristics as a calibration point associated with that location and that ping at that given time. The return signal and / or its characteristics are later used as a calibration signature corresponding to the time at which the material is considered to have a baseline state of structural integrity.

[0248] In a second step (step 2122), performed at some later time after the first step, the technician repeats the pinging and signature capture process to collect current data returned by the split-ring resonators within the structural member. A comparison between the calibration signature and the current data may indicate a change in material integrity. On the other hand, a change in response 1918 may merely indicate a change in compression. A range of changes in compression over time may be considered normal and may occur during normal use (e.g., when a structure bends under stress due to tectonic activity such as an earthquake). In addition to the techniques described above for measuring changes in compression, further techniques are presented herein for measuring changes in bending. Regardless of the shape of the member, the required information can be gathered using the techniques described above, or any related techniques disclosed herein.

[0249] The calibration points are then compared to the calibration signature. If the difference between the two signals is outside the acceptable error threshold or tolerance (the "Yes" option of decision 2124), the "Yes" branch of decision 2124 is taken and a report is generated (step 2126). Furthermore, Figures 22A1-22A3 show other embodiments that apply the foregoing.

[0250] 22A1 through 22A3 are presented to illustrate the use of a split-ring resonator or multiple split-ring resonators in a roadside barrier, according to one embodiment. Optionally, FIGS. 22A1 through 22A3 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that FIGS. 22A1 through 22A3 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0251] As shown, FIG. 22A1 illustrates a roadway 2202 that includes a concrete barrier 2206 and / or a metal barrier 2204, or possibly both, using a split-ring resonator or multiple split-ring resonators. The roadside barrier is intended to mitigate the severity of a potential vehicle accident (e.g., going over a cliff, driving into a body of water, etc.) by allowing the shape of the barrier body to deform, absorbing the force from an oncoming vehicle and stopping the vehicle from continuing down its path. After this is achieved, the barrier's material integrity may change and, in some cases, it may need to be replaced due to material deformation. Even if the outer physical aspects of the barrier appear unchanged, the barrier may need to be replaced because it may have weakened due to deformation within the material as a result of the impact.

[0252] To determine when and how often a given barrier may need to be replaced, split-ring resonators may be placed within the concrete barrier, as shown in FIG. 22A2 (e.g., one example of the technique shown in FIG. 19A). Once the foundation or structure has cured, the split-ring resonators can be calibrated, and an initial state or calibration signature can be collected, for example, by a two-step technique. In the first step, a technician operates a signal generator (or similar tool) and tunes the signal generator to a selected frequency to emit a signal proximate to the split-ring resonators within the concrete barrier. The return signal and / or its characteristics (e.g., attenuation, single-frequency resonance, multiple-frequency resonance, etc.) from the split-ring resonator are captured. The technician stores the return signal and / or its characteristics as a calibration point associated with that location and the ping at that given time. The return signal and / or its characteristics are later used as a calibration signature corresponding to the point in time at which the material is considered to have a baseline state of structural integrity.

[0253] The same can be applied to the metal barrier depicted in FIG. 22A3. The split ring resonators may also be attached by an applied technique (e.g., ultrasonic welding) in step 2112. Once attached to the metal barrier, the split ring resonators can be calibrated and an initial state or calibration signature can be collected using the previous two-step technique. Similarly, racetrack barriers can also use multiple split ring resonators to monitor the integrity of the barrier, as shown in FIG. 22B.

[0254] It should be understood, of course, that split ring resonators can be embedded in other materials (other than the concrete barrier of FIG. 22A2 and / or the metal barrier of FIG. 22A3) including, but not limited to, aviation-related embodiments (e.g., wings, landing gear, airplane components, etc.), nautical-related embodiments (e.g., sails, masts, buoys, structural steel, etc.), utility-related embodiments (e.g., power line structures, transmission lines, piping, etc.), construction-related embodiments (e.g., beams, concrete pylons, etc.), biomedical-related embodiments (e.g., prosthetics, implants, orthotics, etc.), professional sporting goods-related embodiments (e.g., helmets, protective padding, hand tools, footwear, etc.), forging or smelting-related embodiments (e.g., metals, composites, alloys, etc.), power generation-related embodiments, and the like. Examples of embodiments may include solar arrays, hydroelectric dams, wind turbines, natural gas containment and transportation, automotive safety and / or performance embodiments (e.g., engine performance, suspension, chassis and body integrity, etc.), manufacturing related embodiments (e.g., assembly, 3D printing, component integration, testing, etc.), agriculture related embodiments (e.g., growth rate, temperature control, moisture saturation, UV light exposure, etc.), and / or space travel related embodiments (e.g., airlock performance, propellant receptacle integrity, measuring launch effect tolerances, in-flight capsule / vehicle distortion, etc.). In short, the use of split ring resonators to determine deformation of an affixed or incorporated material may be relevant to any application in which the split ring resonator is embedded and / or can be affixed, and the substrate to which the split ring resonator is affixed or embedded is of a sufficiently permanent state that any substrate deformation is an indication of material fatigue.

[0255] To take one specific example, in marine applications, drilling rigs are often exposed to high temperatures and corrosive environments. Conditions such as these often lead to drill pipe failure, primarily due to metal fatigue. In one embodiment, embedding a split-ring resonator within the drill pipe itself allows for detection of metal fatigue before it leads to drill pipe failure (and the inherent challenges that result from such failure). Consistent with the description herein, the split-ring resonator embedded in the drill pipe may first be calibrated, and an initial state or calibration signature may be collected (consistent with the two-step technique). A signal generator (or similar tool) may emit a signal next to the split-ring resonator within the drill pipe, with the signal generator tuned to a selected frequency. Return signals and / or their characteristics may be captured and stored as a calibration signature for the material's current state. Thereafter (consistent with step 2116), a stimulus may be applied (per step 2118), the response may be measured (per step 2120), and compared to the calibration signature (per step 2122). It should be understood that the stimulus may be applied at any time period (e.g., every minute, daily, weekly, monthly, etc.) predetermined by the user. In this manner, deformations in the drill pipe (which may be indicative of fatigue cracks, crack propagation, etc.) may be measured and detected before they actually cause drill pipe failure.

[0256] FIG. 22B depicts a roadside barrier 22B00 used within a racetrack, showing the structural components that make up the roadside barrier, in which one or more split-ring resonators may be disposed, according to one embodiment. Optionally, roadside barrier 22B00 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or the description thereof. However, it should be understood that roadside barrier 22B00 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0257] In one embodiment, roadside barrier 22B00 may include a steel and foam energy-reducing barrier. As shown, the race track is flanked by foam absorbers (including internal split-ring resonators 2208). Steel and foam energy-reducing barriers may be used within certain high-speed sections of the track and may function to not only reduce the severity of an accident by absorbing kinetic energy during a collision, but also to isolate spectators from potential danger in the event of a car collision and / or prevent hazards from flying toward spectators. If the barrier contacts one or more cars, the absorbed energy is transferred along the side of the wall, reducing damage to the cars and preventing injury to spectators.

[0258] Additionally, an array of split ring resonators 2212 can be positioned either on and / or within the putter steel barrier 2210 to determine the integrity of the barrier, such as after one or more impacts, or to obtain the information necessary to determine the integrity of the barrier over a period of time. In an exemplary case, the array of split ring resonators 2212 can be positioned within the front and rear of the putter steel barrier and / or embedded on or within either a foam absorber and / or a cement wall.

[0259] In one specific embodiment, the array of split ring resonators 2212, once placed (e.g., after being placed within a foam absorber containing internal split ring resonators 2208, and / or after being placed outside or within a putter steel barrier 2210, and / or after being placed outside or within a foam absorber), can be calibrated by the two-step technique detailed herein.

[0260] In a first step, a technician operates a signal generator (or similar tool) and tunes it to a selected frequency, which emits a signal proximate to a split ring resonator within the foam absorber containing the internal or external split ring resonator 2008 and / or external or internal to the putter steel barrier 2210. The return signal and / or its characteristics (e.g., attenuation, single frequency resonance, multiple frequency resonance, etc.) from the split ring resonator are captured. The technician stores the return signal and / or its characteristics as a calibration point associated with that location and that ping at that given time. The return signal and / or its characteristics are later used as a calibration signature corresponding to the point in time at which the material is considered to have a baseline state of structural integrity.

[0261] In a second step, performed at some later time after the first step, the technician repeats the pinging and signature capture process to collect current data returned by the split-ring resonators within the structural member. A comparison between the calibration signature and the current data may indicate a change in material integrity. On the other hand, a change in response 1918 may merely indicate a change in compression. A certain range of changes in compression over time may be considered normal and may occur during normal use (e.g., when a structure flexes under stress due to tectonic activity such as an earthquake). In addition to the aforementioned techniques for measuring changes in compression, further techniques are presented herein for measuring changes in bending. After analyzing the collected data, a report can be generated from which a decision can be made to replace the barrier.

[0262] 23 shows a representation 2300 of a split-ring resonator disposed on the surface of a concrete structure after the concrete has been poured into a given structural form, according to one embodiment. Optionally, representation 2300 may be implemented in the context of any one or more of the embodiments described in any of the previous and / or subsequent figure(s) and / or their description. However, it should be understood that representation 2300 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0263] As shown, depiction 2300 includes split ring resonators (e.g., split ring resonator 19041, split ring resonator 19042, split ring resonator 19043) that are placed on the surface of a concrete structure (e.g., column or wall 1908) after the concrete has been poured into a given structural form. Placement of such split ring resonators (e.g., the illustrated surface-applied split ring resonator 2302) can be done as a "retrofit," possibly after a period of time has passed since pouring and curing, and possibly after a building has been constructed using the column and / or wall. The construction, placement, and means of affixing the surface-applied split ring resonators 2302 to a structure can be accomplished using any known techniques. For example, such surface-coated split ring resonators 2302 can be printed or silkscreened onto a substrate in a roll, and the roll of substrate, or portions thereof, can be coated onto the surface of a post or wall, optionally using an adhesive. In some cases, the substrate is lifted off, leaving the surface-coated split ring resonators 2302 affixed to the surface of the post or wall. In some cases, the surface-coated split ring resonators 2302 can be printed directly onto rebar. In some cases, the surface-coated split ring resonators 2302 can be printed onto a substrate using an inkjet or bubble jet printer. In some cases, the surface-coated split ring resonators 2302 can be printed onto a substrate using an offset or printing process (e.g., multicolor offset printing). In some cases, the surface-coated split ring resonators 2302 can be printed onto a substrate using gravure printing techniques.

[0264] The calibration and test module 2301 can be located proximate to any location where there is a split ring resonator 2302 coated on a surface. One or more calibration signatures based on a particular combination of the presence of the emitted RF signal 210 and the presence of the corresponding return RF signal 212 can be communicated over the network to the upstream components 113. By way of example, strictly relevant to this and other embodiments, the upstream components may include, but are not limited to, modules that perform continuous inspection and analysis of structures, modules that couple to perform the function of an early warning system, modules that comply with governance, and / or modules that comply with any regulatory reporting requirements.

[0265] Any of the aforementioned techniques for fabricating and using split ring resonators can be combined. For example, surface-coated split ring resonators can be retrofitted onto the surface of a roadside barrier and / or its components. Additionally, for example, upstream components may include racetrack safety monitoring units. Furthermore, split ring resonators of a first geometric shape (e.g., concentric rings) of split ring resonators can be combined (e.g., closely juxtaposed) with split ring resonators of a second geometric shape (e.g., concentric cylinders). Specifically, in yet another embodiment, a roadside barrier made of steel and / or other barrier components made of steel of another conductive material can function as a conductive layer that is dielectrically separated (e.g., by an adhesive) from any one or more split ring resonators disposed on the surface of the roadside barrier.

[0266] As previously mentioned, various methods have been disclosed for incorporating or otherwise embedding split ring resonators within a substrate (e.g., a cement pour, etc.) that forms the intended structural member. Also as previously mentioned, various methods have been disclosed for affixing split ring resonators onto the surface of a structural member (e.g., a tie rod in a steering mechanism in an automobile, etc.). Additionally, as also described herein, it is contemplated to use an RF "horn" to emit a specific signal and measure the response of the embedded split ring resonator.

[0267] Some methods include placing the split-ring resonator on a (possibly printed) "ground plane" to form an assembly and then painting it onto the surface of a structural member, which can greatly increase the sensitivity of the split-ring resonator over a wide range of EM.

[0268] The above-described method supports static nondestructive testing by simply comparing a current response / signature with a previously acquired calibration response / signature and then classifying the difference between the two signatures. More specifically, certain differences evident between the signatures can be correlated to changes in corresponding physical properties. In some cases, the changes in physical properties indicate aging (e.g., embrittlement). In other cases, the changes in physical properties indicate stretching, compression, other deformation, etc.

[0269] In some cases, changes in physical properties indicate changes in dynamically changing characteristics (e.g., vibration). Dynamic nondestructive testing is supported by capturing a series of dynamically acquired responses / signatures against a previously acquired series of calibration responses / signatures. Apparent differences between the two sets of signatures can be correlated to changes in physical properties, such as cyclic deformation. In some cases, changes in physical properties indicate aging (e.g., changes in the elastic deformation curve). In some cases, changes in physical properties occurring between readings and / or measured when comparing one series of readings with another series of readings can indicate elastic versus plastic deformation, which may indicate impending failure. Specifically, as one example, impending failure of a component may be indicated when a measured elastic curve (e.g., based on a series of readings) resembles a region of the elastic curve designated as preceding a failure event.

[0270] 24A illustrates a sensing stack 24A00 including alternating layers of carbon-containing resin and carbon fiber in contact with one another, according to one embodiment. Optionally, sensing stack 24A00 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that sensing stack 24A00 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0271] As shown, sensing stack 24A00 includes a schematic cross-sectional side view composed of multiple layers disposed on top of one another, including (sequentially) carbon-containing resin 24042, carbon fiber 24022, carbon-containing resin 24041, and carbon fiber 24021. In one embodiment, sensing stack 24A00 can represent any of the sensors described with reference to those shown in Figures 24A-24C. The term "resin" (in polymer chemistry and materials science) generally refers to a solid or highly viscous substance of plant or synthetic origin that is typically convertible into a polymer (a large molecule or macromolecule composed of many repeating subunits). Synthetic resins may be industrially produced resins or may be viscous substances that are typically converted into rigid polymers during curing. To undergo curing, resins typically contain reactive end groups such as acrylates or epoxides. The term "carbon fiber" refers to fibers approximately 5-10 micrometers (μm) in diameter and composed mostly of carbon atoms. Carbon fiber offers several advantages, including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature resistance, and low thermal expansion.

[0272] Any one or more of the carbon-containing resin 24042, carbon fibers 24022, carbon-containing resin 24041, and carbon fibers 24021 can be tuned to demonstrate or exhibit one or more specific resonant frequencies when an RF signal emits a ping by incorporating specific concentration levels of any one or more of the aforementioned carbon-containing microstructures. The sensing stack can include any configuration, orientation, order, or layer of any one or more of the carbon-containing resin 24042, carbon fibers 24022, carbon-containing resin 24041, and carbon fibers 24021, and / or fewer or additional layers comprising similar or dissimilar materials. Additional resin layers can be layered between additional carbon fiber layers.

[0273] Each carbon-containing resin layer can be separately formulated to resonate at a different intended or desired tuning frequency. The physical phenomenon of material resonance can be explained in terms of the corresponding molecular composition. For example, a layer having a defined first structure, such as a first molecular structure, can resonate at a first frequency, while a layer having a different second molecular structure can resonate at a different second frequency.

[0274] A material contained within a layer with a particular molecular structure resonates at a first tuning frequency when the layer is in a low-energy state and at a different second frequency when the material within the layer is in an induced high-energy state. For example, a material within a layer exhibiting a particular molecular structure can be tuned to resonate at 3 GHz when the layer is in its natural, undeformed, low-energy state. In contrast, the same layer can resonate at 2.95 GHz when the layer is at least partially deformed from its natural, undeformed, low-energy state. As a result, this phenomenon can be tailored to address the need for high-fidelity and precision detection of even the slightest anomalies, such as those on a tire surface that contacts a road surface such as pavement and experiences severe wear at specific localized contact areas. Race cars racing on demanding race circuits (referring to highly technical, windy tracks characterized by sharp turns and rapid elevation changes) can benefit from such localized tire wear or degradation information to make informed tire replacement decisions, even under time-sensitive race-day conditions. As described herein, this phenomenon can be applied to any situation and / or application where a split ring resonator can be integrated into or affixed to a substrate.

[0275] 24B1 and 24B2 illustrate a frequency shift phenomenon as exhibited by a sensing stack including a carbon-containing RF-tuned resonant material, according to one embodiment. Optionally, FIGS. 24B1 and 24B2 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that FIGS. 24B1 and 24B2 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0276] The frequency shift phenomenon (such as the transition from a resonance at a frequency of 3 GHz to 2.95 GHz with respect to FIG. 24A) is shown above and discussed with reference to FIGS. 24B1-24B2, which depict the frequency shift phenomenon as shown in a sensing stack including a carbon-containing tuned resonant material.

[0277] As is commonly understood, atoms emit electromagnetic radiation at frequencies characteristic of a given element. That is, atoms of a particular element have characteristic vibrational frequencies that correspond to the properties of that atom. For example, when a cesium atom is stimulated, its valence electrons jump from a low-energy state (e.g., the ground state) to a higher-energy state (e.g., an excited energy state). When the electrons return to their lower-energy state, they emit electromagnetic radiation in the form of photons. In the case of cesium, the emitted photons are in the microwave frequency range at 9.192631770 THz. Larger structures, such as molecules formed from multiple atoms, also resonate (e.g., by emitting electromagnetic radiation) at predictable frequencies. For example, liquid water in the bulk resonates at 109.6 THz. Water under tension (e.g., at the surface of the bulk, in various surface tension states) resonates at 112.6 THz. Carbon atoms and carbon structures also exhibit characteristic vibrational frequencies that depend on the structure. For example, the natural resonant frequency of carbon nanotubes (CNTs) depends on the diameter and length of the CNT tubes. Growing CNTs under controlled conditions to control the tube diameter and length allows for control of the natural resonant frequency of the structure. Thus, synthesizing or otherwise "growing" CNTs is one way to tune to a desired resonant frequency.

[0278] Other structures formed from carbon can be formed under controlled conditions. Such structures include, but are not limited to, carbon nano-onions (CNO), carbon lattices, graphene, carbon-containing strong or weak aggregates, graphene-based, other carbon-containing materials, artificial nanoscale structures, and / or combinations thereof, any one or more of which may be incorporated into sensors for vehicle components according to embodiments of the present disclosure. Such structures can be formed to resonate at specific tuned frequencies, and / or such structures can be modified by post-processing to obtain desired characteristics or properties. For example, desired properties such as high reinforcement values ​​can be achieved through the selection and ratio of material combinations and / or the addition of other materials. Furthermore, the juxtaposition of multiple such structures introduces additional resonance effects. For example, two graphene sheets can resonate with each other at a frequency that depends on the length, width, spacing, spacing geometry, and / or other physical properties of the sheets and / or their juxtaposition with each other.

[0279] As is known in the art, materials have specific, measurable properties. This applies not only to naturally occurring materials, but also to artificial carbon allotropes. Such artificial carbon allotropes can be tuned to exhibit physical properties. For example, carbon allotropes can be engineered to exhibit physical properties corresponding to (a) a particular arrangement of constituent primary particles, (b) the formation of strong aggregates, and (c) the formation of weak aggregates. Each of these physical properties affects the specific resonant frequency of a material formed using the corresponding specific carbon allotrope.

[0280] In addition to tuning a particular carbon-based structure to a particular physical configuration that corresponds to a particular resonant frequency, a carbon-containing compound can be tuned to a particular resonant frequency (or set of resonant frequencies), which set is referred to as a resonant profile.

[0281] 24B1 shows a first carbon-containing structure resonating at a first frequency, which can be correlated to an equivalent electrical circuit including a capacitor C1 and an inductor L1 (note that the context for Equation 3 provided below can also be found herein above, with respect to FIG. 2, and / or with respect to the carbon-containing structures of FIGS. 18A-18Y, among others). The frequency f1 is given by:

number

[0282] Figure 24B2 shows a slight deformation of the same first carbon-containing structure of Figure 24B1. The deformation causes a change in the physical structure, which in turn changes the inductance and / or capacitance of the structure. These changes can be correlated to an equivalent electrical circuit including capacitor C2 and inductor L2. The frequency f2 can be given by:

number

[0283] 24B3 is a graph 24B300 illustrating an idealized change in RF resonance as a function of deflection, according to one embodiment. Optionally, graph 24B300 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that graph 24B300 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0284] As shown, graph 24B300 shows an idealized change in measured resonance as a function of deflection. Optionally, one or more variations of graph 24B300, or any aspect thereof, can be implemented in accordance with the embodiments described herein. Graph 24B300 (or any aspect thereof) can be implemented in any environment.

[0285] The embodiment shown in FIG. 24B3 is merely an example. The graph shown illustrates one aspect of deformation, specifically deflection. When a member or surface undergoes deformation (such as bending) through deflection, the deformation can change the member's exhibited resonant frequency when pinged by a signal, such as an RF signal. The shape of that curvature can depend on the properties of the member, such as the properties of the laminates forming the member or surface. This curvature can be steep with small variations, but when the deflection reaches a maximum, the curve flattens out. Furthermore, the shape of the curvature depends in part on the number of layers in the laminate, the geometry of the carbon structure, how the carbon is bonded to the laminate, etc.

[0286] 24B4 is a graph 24B400 illustrating changes in RF resonance for four-layer and five-layer stacks, according to one embodiment. Optionally, graph 24B400 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that graph 24B400 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0287] As shown, graph 24B400 shows the change in resonance for four-layer laminate 292 and five-layer laminate 294. Optionally, one or more variations of graph 24B400, or any aspect thereof, can be implemented in the materials and systems described herein. Materials such as the described laminates can be deployed in many applications. One particular application may be for surface sensors, which can be deployed in, on, or across many locations throughout a vehicle. One example of such a deployment may be shown and described in connection with FIG. 24C.

[0288] 24C illustrates a surface sensor deployment in the area of ​​vehicle 24C00, according to one embodiment. Optionally, vehicle 24C00 may be implemented in any one or more of the embodiments described in any of the front and / or rear view(s) and / or description thereof. However, it should be understood that vehicle 24C00 may be implemented in any desired environmental context. Additionally, the foregoing definitions may apply equally to the following description.

[0289] As shown, vehicle 24C00 illustrates an exemplary surface sensor deployment at a selected location on the vehicle. Such exemplary surface sensor deployments, or any aspect thereof, may be implemented in or on a vehicle exposed to any possible external environmental condition, such as snow, sleet, hail, etc.

[0290] Tuned resonant sensing carbon-containing materials can be incorporated into or coupled to automotive features, surfaces, and / or components in the context of durable sensors within various exterior surfaces of the vehicle. As shown, the vehicle includes surface sensors on the vehicle's front fairing (e.g., hood), vehicle support members, and vehicle roof. Each of these locations on the vehicle may be subject to stresses and associated deformations during vehicle operation. By way of example, the surface sensor on the front fairing experiences air pressure changes during vehicle operation (e.g., forward motion). Under the force of air pressure, the material comprising the surface may deform slightly and exhibit a change in the resonant frequency of the material proportional to the degree of material change or deformation, in accordance with the phenomenon described in connection with FIGS. 24B1 and 24B2. Such changes can be detected using the "ping" and observation techniques described above.

[0291] The observed emitted signals can be collectively defined as a signature for a particular material or surface and can be further classified. Specific characteristics of the signals can be isolated for comparison and measurement, and calibration points corresponding to the specific isolated characteristics can be determined. Therefore, aspects of the environment surrounding the vehicle can be accurately and reliably determined.

[0292] For example, if deformation of a surface sensor shifts the frequency from 3 GHz to 2.95 GHz, mapping that difference to a calibration curve can yield a value for air pressure. Vehicle components such as panels, roofs, hoods, trunks, or airfoil components can offer relatively large surface areas. In these cases, a transceiver antenna can be positioned on the observable side of the component. Several transceiver antennas can be arranged in an array, with each element of the array corresponding to a section of the large surface area. Each transceiver antenna can be installed on or within the wheel well of a surface sensor deployment 24C00 as shown and can be independently stimulated with pings / chirps. In some cases, each element of the array can be stimulated sequentially, while in other cases, each element of the array is stimulated simultaneously. Vehicle aerodynamics can be measured over a large surface area with signal processing used to distinguish signature returns from proximal array elements.

[0293] The signature return from a particular array element can be analyzed with respect to other environmental conditions and / or other sensed data. For example, the deflection of a particular portion of the airfoil component may be compared to the deflection of a different portion of the airfoil component, and then analyzed with respect to the current temperature, and / or the current tire pressure, and / or other sensed aspects of either the vehicle or its environment. As previously described, a resonator circuit (as shown in FIGS. 24B1 and 24B2) can be implemented by placing resonators within a surface panel of the vehicle (as shown in FIG. 24C). In other embodiments, the placement is specifically tuned to allow placement of resonators (e.g., split-ring resonators) across the entire surface of the vehicle. An array or matrix of surface sensors of various sizes can be deployed in or on many locations throughout the vehicle to currently analyze the vehicle's condition. One such deployment can be found, for example, in FIG. 29, described herein below.

[0294] 25A provides a depiction 2500 of an interaction between a vehicle and a split-ring resonator disposed in road asphalt and / or on the road surface, according to one embodiment. Optionally, depiction 2500 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or description thereof. However, it should be understood that depiction 2500 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0295] As shown, representation 2500 may include a vehicle 2502, a split ring resonator 2504 disposed in and / or on a road surface, and the vehicle's interaction with the road surface 2506. In one embodiment, representation 2500 may be used to determine tire stiction (and / or rolling friction). For example, maintaining static contact with the road allows for control of the vehicle (while loss of static contact with the road may result in loss of vehicle control). Split ring resonator 2504 may be used to measure tire (and / or interface) stiction (as a function of tire tread thickness). A process for determining tire stiction is described in more detail below with reference to FIG. 27.

[0296] 25B provides a depiction of how a split-ring resonator disposed in or on a tire can be used to measure tire stiction, according to one embodiment. Optionally, depiction 2500 may be implemented in the context of any one or more of the embodiments described in any of the before and / or after figure(s) and / or description thereof. However, it should be understood that depiction 2500 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0297] As shown, representation 2501 may include a vehicle 2502, a split ring resonator 2503 located in and / or on a tire, and tire interaction 2505. In one embodiment, representation 2501 may be used to determine tire stiction (and / or rolling friction). For example, split ring resonator 2503 located in and / or on a tire may be used to measure tire (and / or interface) stiction (as a function of tire tread thickness).

[0298] In various embodiments, split ring resonators 2504 located in and / or on the road surface and split ring resonators 2503 located in and / or on the tire may be used to measure the actual stiction of the tire relative to the road surface, and may measure the actual thickness of the tire on the road surface. These measurements may be made in real time, even while the vehicle 2502 is in motion. In this way, tire stiction may be measured continuously (or near-continuously) with high accuracy, because split ring resonators 2504 and 2503 do not rely on electronics (which are prone to malfunctions and other mechanical problems).

[0299] As an example, in the car racing industry, while the vehicle 2502 is in motion, split ring resonators (located in and / or on the vehicle, such as tires, and / or in and / or on the road) may provide real-time permittivity data regarding tire stiction to the driver and pit crew in real time. Such real-time data allows immediate feedback on how the tires are responding to and interacting with the road surface, allowing the driver and pit crew to adjust and fine-tune the vehicle (e.g., tire tread type, tire power delivery, windshield, wings, spoilers, etc.) to increase tire stiction (minimizing and maximizing vehicle control and performance). Of course, any other fine-tuning of the vehicle may be performed to ensure tire stiction.

[0300] In one embodiment, split ring resonators 2504 and 2503 may be low-cost sensors because they do not rely on electronics to function. In this manner, split ring resonators 2504 and 2503 may not only improve real-time data collection (with greater accuracy), but may also be less expensive than current alternatives.

[0301] 26 illustrates an arrangement 2600 of split-ring resonators disposed within road asphalt and / or on the road surface, according to one embodiment. Optionally, arrangement 2600 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that arrangement 2600 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0302] As shown, the arrangement 2600 includes a vehicle 2602, a split ring resonator 2604, and a vehicle interaction 2606. The location of the split ring resonator 2604 (as shown in FIG. 26) is arbitrary. An important point about the locations of split ring resonators 2604 such as these is that they can be placed anywhere in or on the road surface. In one embodiment, FIG. 26 may apply to a race car track, where more split ring resonators 2604 may be required (for increased data collection and fine-tuning of performance). In contrast, in other applications, such as on regular highways or streets, the locations of the split ring resonators 2604 may be spaced more apart (because fine-tuning of performance may not be required).

[0303] As described herein, split ring resonator 2604 may be used to collect data regarding tire stiction. Such data may be used to modify vehicle-related parameters. Furthermore, such data may be used for safety (of the vehicle and / or roadway). For example, if split ring resonator 2604 determines that real-time stiction levels have decreased (indicating loss of traction), traffic information may immediately alert other drivers to dangerous road conditions (as well as reduce speed limits in and / or around areas where loss of traction is detected). In this manner, split ring resonator 2604 may be used for traffic management and / or safety.

[0304] Additionally, split ring resonators, such as those located within and / or on a tire (such as split ring resonator 2503), may be used as a replacement for traditional antilock braking systems (which typically rely on wheel speed sensors and vehicle speed sensors to determine if a tire has stopped rotating). Split ring resonator 2503 may provide more accurate data with less latency (e.g., milliseconds between detection and reporting to a control module). Furthermore, because split ring resonator 2503 does not rely on electronics to function (as opposed to traditional sensor systems), it is less prone to errors and malfunctions.

[0305] In another embodiment, the split ring resonator 2604 may be used to determine driver competence and / or track driver performance. For example, if an overly enthusiastic driver accelerates suddenly or an aggressive driver brakes aggressively, such data may be used to create a driver profile (of the driver's performance). For drivers in training (and in need of objective data feedback), such data may be used to aid in driver training (to learn more comfortable driving techniques). Furthermore, such data may be tied to auto insurance carriers, where preferential rates may be associated with a tendency for less aggressive driving history.

[0306] In this manner, the split ring resonator 2604 may be used in a variety of scenarios where tire stiction measurements may be used to better control the vehicle (ensuring traction between the vehicle and the road surface), as well as for safety, driver training, insurance carrier rates, etc. based on such collected data.

[0307] 27 is a flowchart 2700 illustrating a process for determining tire stiction, according to one embodiment. Optionally, flowchart 2700 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that flowchart 2700 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0308] As shown, flowchart 2700 begins by determining the tire tread thickness (step 2702). Next, a current measurement is determined (step 2704). For example, the current measurement may include deformation of the split-ring resonator at the point where the tire contacts the road. Such deformation may be measured (in the form of a frequency shift) and tracked by ensemble effects (related to and / or affected by the effects causing the deformation) to the dielectric constant of the surroundings, including, but not limited to, water, tar, blacktop (asphalt), concrete, etc. If the current measurement matches the baseline measurement (per decision 2706), the method returns to step 2702 to determine the tire tread thickness and step 2704 to determine the refractive index. If the refractive index does not match (per decision 2706), method 2700 proceeds to step 2708 to adjust the vehicle to achieve a match.

[0309] In one embodiment, the refractive index can be related to measuring the reflectivity (which can be used) for each tire layer and determining the dielectric constant of each tire layer. When tire stiction is high, the tread thickness (and therefore the reflectivity and dielectric constant) increases proportionally. When tire stiction is lost (i.e., traction is lost), there is a mismatch (i.e., the reflectivity and dielectric constant are not proportional) with respect to the tire tread thickness. In this way, the tire tread thickness can be used to determine tire stiction as a function of the refractive index (and therefore the reflectivity) and dielectric constant.

[0310] Additionally, refractive index mismatches in composite materials (e.g., tires, asphalt, plastics, rubber, metal alloys, etc., among others) may be used to sense variations in scattering parameters (or S-parameters, elements of a scattering matrix, etc.) of stiction levels. Scattering parameters such as these may be related to stimulating (by radio signals) one or more split-ring resonators located in or on the tire (or vehicle, vehicle component, road surface, etc.). One or more split-ring resonators such as these may be used to obtain instantaneous readings of tire tread thickness (which may be used to determine tire stiction, as described herein above).

[0311] Additionally, the use of split ring resonators (as the basis for determining tire stiction) provides a very economical, small form factor solution that does not rely on electronics to function. Therefore, factors such as these, combined with low latency and high accuracy, make split ring resonators a viable solution for many applications.

[0312] 28 illustrates a correlation 2800 between measured frequency and tread thickness, according to one embodiment. Optionally, correlation 2800 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that correlation 2800 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0313] As shown, tire 2802 includes a plurality of one or more tire belt plies (in a manner consistent with tire 1002). Carbon-based microstructures incorporated within tire 2802 may include split ring resonators. Split ring resonators such as these may have a natural resonance (such as about 1.0 GHz) and may cause tire 2802 to deform and / or otherwise change in response to external conditions (such as driving the tire). The deformation and / or changes within tire 2802 may be measured as a frequency response (in terms of response damping) of the split ring resonators.

[0314] The frequency response is shown in model 2804. In one embodiment, model 2804 can be correlated with impedance spectroscopy energy between the tire and the tire. Such energy (measured in terms of frequency) can be used to determine tire stiction. For example, the tire thickness of tire 2802 can change, such as between a natural state and an in-use driving condition. During an in-use driving condition, tire 2802 can have stiction (and traction) with the road surface. Such a condition (having tire stiction) can be correlated with a matching frequency model (shown in model 2804, in one example). However, if tire stiction is lost (i.e., a loss of tire traction occurs), the corresponding model 2804 may no longer match. For example, the dielectric constant may rapidly decrease when stiction is lost. Calibrating the degree to which stiction operates under different conditions allows for comparison of current readings (and changes in readings), which can be compared to a calibration curve.

[0315] In this manner, impedance spectroscopy may be used to measure frequency samples of split ring resonators in or on a tire. It should be understood that while correlation 2800 is shown with respect to one embodiment of a tire, other applications (e.g., related to automobile components, automobile skins, road conditions, metal fatigue conditions, construction materials, etc.) are envisioned in a similar manner.

[0316] In this manner, split ring resonators can be placed in and / or on materials (including internal components such as wiring or external components such as road asphalt) and can be used to provide information about the material in and / or on which they are placed.

[0317] 29 illustrates a section 2900 of a vehicle surface on which an array of individually configured split-ring resonators is disposed, according to one embodiment. Optionally, section 2900 may be implemented in the context of any one or more of the embodiments described in any of the front and / or rear figure(s) and / or description thereof. However, it should be understood that section 2900 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0318] As shown, a section of the vehicle surface 2902 may be subjected to stresses and associated deformations during vehicle operation, resulting in split ring resonators (F in FIG. 29). 11 , F 12 , F 13 , F 21 , F 22 , F 23 , maximum F NN (shown as ) can be used to sense changes that may occur in materials under such environmental stresses and deformations. Split ring resonators may be printed or painted onto a vehicle's sponge material (e.g., a vehicle vinyl wrap), and / or a combination of resonators and sponge material may be placed over the entire vehicle or a section of the vehicle surface of interest.

[0319] For example, split ring resonators on a front bumper may experience changes in air pressure during vehicle operation (e.g., during forward motion, thus generating a downward force on this section of the vehicle). Under the force of air pressure, the material comprising the surface may deform slightly and exhibit a change in resonant frequency of the material proportional to the degree of material change or deformation, in accordance with the phenomenon described in connection with FIGS. 24B1 and 24B2. While all split ring resonators are resonating simultaneously, a difference in one of the split ring resonators, or among multiple split ring resonators, can be determined by a change in pitch, which can be sensed by a stimulus / response comparator, such as may be implemented in whole or in part by a horn / receiver or similar device.

[0320] The array or matrix of split ring resonators on the vehicle surface 2902 and the components are configured so that the frequency response of any of the component members of the array does not clash with adjacent split ring resonators. One such arrangement is shown and depicted in connection with FIG.

[0321] 30 illustrates an arrangement 3000 of split-ring resonators within a frequency bin, according to one embodiment. Optionally, arrangement 3000 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that arrangement 3000 may be implemented in the context of any desired environment. Furthermore, the foregoing definitions may apply equally to the following description.

[0322] As shown, the split ring resonator (F 11 , F 21 , maximum F NNEach frequency bin can contain a different frequency response (denoted as ). When a surface containing split-ring resonators deforms due to deflection, positive or negative deflections can change the physical properties of the split-ring resonators, thereby shifting the natural center frequency of the component. The variation in the component's frequency response is represented by the Δ symbol in FIG. 30. This change in resonant frequency, even at its maximum, as shown, may not collide with adjacent split-ring resonators. Measuring periodic deflection over time facilitates detection of periodic stresses (e.g., buffeting) occurring on the vehicle surface. One such example for detecting time-based deflection variations is shown and described in connection with FIG. 31.

[0323] 31 illustrates a chart 3100 of detecting time-based variations in deflection, as indicated by time-based variations in resonant frequency, according to one embodiment. Optionally, chart 3100 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that chart 3100 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0324] As shown, chart 3100 illustrates the ongoing measurement of the periodic deflection of split-ring resonators to detect time-based variations in deflection, which may enable analysis of pressure on a given vehicle control surface. For example, combining the aforementioned technique of distributing an array of split-ring resonators across a vehicle control surface with a technique for analyzing the combined returns from the individual split-ring resonators on that control surface may enable identification of areas of that surface that are subject to periodic stress (e.g., buffeting). In some cases, changes in physical properties indicate relatively high-frequency, dynamically changing fluctuations in characteristics (e.g., vibrations). Dynamic non-destructive testing may be facilitated by capturing a series of dynamically acquired responses / signatures and comparing them to a previously acquired series of calibration responses / signatures, etc. Appearance differences between the two sets of signatures may be correlated to changes in physical properties, such as periodic deformation (e.g., buffeting).

[0325] 32 illustrates a signature classifying system 3200 for processing signals received from a sensor formed from a carbon-containing tuned resonant material, according to one embodiment. Optionally, the signature classifying system 3200 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that the signature classifying system 3200 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0326] In one embodiment, the signature classification system 3200 can be implemented in any physical environment. More specifically, the signature classification system 3200 illustrates an example of a method for classifying a signal (e.g., a signature). As shown, operation 3202 transmits a ping signal at a selected ping frequency. The ping signal generation and ping transmission mechanisms can be implemented using any known technique. For example, a transmitter module can generate a selected frequency of 3 GHz and transmit the signal using one or more horns and multiple receiving antennas. The design and location of the tuned antennas can correspond to the geometry, material, and / or location of any tuned antenna such that the intensity of the ping is sufficient to induce resonance (RF) in the proximity sensor. In some embodiments, several tuned antennas are positioned on or within structural members near the corresponding sensors (e.g., mounted on and / or within one or more of a wheel well or vehicle). In this manner, proximal surface sensors can resonate and return with a signature when stimulated by a ping. In operation 3204, the signature is received and stored in a dataset, which may include the received signature 3210. The sequence of sending a ping followed by receiving a signature may be repeated in a loop until a set of calibration signals is captured, which may be stored as calibration points 3212.

[0327] The ping frequency can be changed (in operation 3208) during repeated passes through decision 3206. Thus, when operation 3202 is performed in a loop (via decision 3206), operation 3204 generates a signature 3210 (first signature 32101, second signature 32102, up to Nth signature 3210). N, and stored. The number of iterations may be controlled by decision 3206. When the "NO" branch of decision 3206 is taken (e.g., when there are no further additional pings to send during the iteration loop), the received signature may be provided to a digital signal processing module (operation 3214). The digital signal processing module classifies the signature against a set of calibration points 3212 (operation 3216). The calibration points may be configured to correspond to particular ping frequencies. For example, the calibration points 3212 may include a first calibration point 32121 that may correspond to a first ping and first return signature near 3 GHz, a second calibration point 32122 that may correspond to a second ping and second return signature near 2 GHz, etc., for any integer value "N" of calibration points.

[0328] In operation 3220, the classified signal is sent to a vehicle central processor. The vehicle central processor (e.g., vehicle central processor 116) can relay the classified signal to an upstream repository (e.g., upstream component 113), which hosts a computerized database configured to host and / or execute machine learning algorithms. Thus, a vast amount of stimuli related to signals, classified signals, and signal responses can be captured for subsequent data aggregation and processing. The machine learning subsystem's database (e.g., training model) can be formed or "trained" by providing a set of sensed measurements and correlating them with conditions related to vehicle performance. Once the database is computationally prepared or "trained," during vehicle operation, the measured deflection (e.g., air pressure) of a particular portion of the airfoil component can be compared to a calibration point, and the comparison results in a frequency delta corresponding to the deflection change corresponding to a particular air pressure. Other potential conditions or diagnoses can be determined by the machine learning system. Status and / or diagnostic and / or supporting data can be made available to instrumentation within the vehicle to complete a feedback loop. In some cases, instrumentation in the vehicle provides visualization that can be performed (such as by the driver or engineer).

[0329] 33 shows a representation 3300 of a split-ring resonator disposed within and / or on a drone and / or drone platform, according to one embodiment. Optionally, representation 3300 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3300 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0330] As shown, drone 3302 may include one or more split ring resonators 3304. In one embodiment, drone 3302 may be used to transport package 3306. Of course, it should be understood that drone 3302 may be configured to carry other items (e.g., cameras, weather sensing equipment, animals, medical supplies, food, goods, cargo, payloads, etc.). Additionally, in other embodiments, drone 3302 may be configured for military or tactical purposes (including being configured as an unmanned combat air vehicle). Further, as described herein below, drone 3302 may be configured as a passenger drone, an unmanned aerial vehicle (UAV), and / or an autonomous aerial vehicle (AAV). In one embodiment, drone 3302 may be capable of vertical take-off and landing (VTOL) and / or electric vertical take-off and landing (eVTOL).

[0331] Additionally, a drone landing pad 3308 is provided and may include one or more split ring resonators 3312. A target location 3310 for aligning the drone 3302 and drone landing pad 3308 is also provided.

[0332] In various embodiments, one or more split ring resonators 3304 can be used to facilitate real-time sensing of the physical state of the drone 3302 and / or environmental conditions external to the drone 3302. Such real-time sensing can occur every millisecond and can be used to detect structural changes within the drone 3302 before they become a problem and / or to alter the course of the drone 3302 to reach its intended final destination (e.g., target location 3310). For example, in one embodiment, if a propeller on the drone 3304 experiences material fatigue (and becomes prone to breakage), a split ring resonator positioned on the propeller can determine the structural change (in terms of a change in frequency). Additionally, any element of the drone 3302 can be monitored such that any structural change can be detected before the adverse effects of that change are observed.

[0333] In another embodiment, the drone 3302 may initiate takeoff or landing on the drone landing pad 3308. Real-time sensing (by one or more split ring resonators 3304) of the state of the drone 3302 may protect both the drone 3302 and / or the drone landing pad 3308. In this manner, the one or more split ring resonators 3304 may detect changes before and / or after takeoff. Note that one or more split ring resonators 3312 on the drone landing pad 3308 may be used to further sense both the state of the landing pad 3308 and / or the position of the drone 3302 (regardless of whether the drone 3302 has one or more split ring resonators 3304). Furthermore, during landing, one or more split ring resonators 3304 on drone 3302, or one or more split ring resonators 3312 on drone landing pad 3308, may be used to determine the pinpoint position of drone 3302 in real time as it approaches drone landing pad 3308. In this manner, one or more split ring resonators 3304 and / or 3312 may be used for high precision landing capabilities.

[0334] Additionally, one or more split resonators 3312 of the drone landing pad 3308 may be used to determine the condition of the drone landing pad 3308 so that material fatigue and / or component failure can be detected before it becomes visually apparent.

[0335] In another scenario, after landing, the status of the drone 3302 may be assessed by receiving health-related data from one or more split ring resonators 3304. For example, the drone 3302 may pass through a drone health system that may broadcast a radio signal. Each of the one or more split ring resonators 3304 may provide a frequency response that may correspond to the structural health (in terms of material fatigue and component failure) of the drone 3302. In this manner, the split ring resonators 3304 may be used to sense the health status of the drone 3302 before, during, and after takeoff and / or landing. The health status may be used to alert and / or communicate to a human / user and / or an autonomous system.

[0336] In this manner, an autonomous system for checking the health of a drone fleet may be achieved. Upon arrival at a landing location, the drone may be inspected and evaluated. If the split ring resonator indicates a structural issue with the drone, the drone may be further inspected (e.g., manually inspected) and / or repaired. If no issues are found with the drone, it may receive a "good health" designation and be ready to be sent out again. In this manner, continuous management of drones may be achieved with respect to the integrity of the fleet's health, and legal and societal constraints regarding drone use, particularly within consumer airspace, may be met.

[0337] 34 shows a representation 3400 of a split-ring resonator disposed in and / or on an air vehicle, according to one embodiment. Optionally, representation 3400 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3400 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0338] As shown, unmanned aerial vehicle (UAV) 3402 may include split ring resonators disposed on air vehicle body 3404, structural component 3406, and / or propeller component 3408. Of course, it should be understood that split ring resonators may be disposed in and / or on any and / or all components of drone 3404.

[0339] In various embodiments, split ring resonators (such as those positioned on the air vehicle body 3404, structural components 3406, and / or propeller components 3408) may be used to obtain real-time (with millisecond time granularity) measurements related to the unmanned air vehicle 3402, including, but not limited to, vibration, strain, changes in dimensional and / or material properties, pressure, and temperature.

[0340] For example, with regard to vibration, split ring resonators can read vibration frequencies (from the Hz level to the hundreds of KHz level). Furthermore, in one embodiment, accelerometers and other non-contact displacement sensors can be used to measure low- to high-frequency vibrations (e.g., from very low frequencies in the low Hertz range, such as in large bridge-like structures, to higher vibrations up to hundreds of kilohertz, such as those found in supersonic applications). With regard to strain, split ring resonators can detect not only component bending / twisting, but also structural fatigue / failure. With regard to changes in dimensions and / or material properties, split ring resonators can determine whether elastomeric components (e.g., those found in tires, belts, hoses, etc.) need to be replaced (due to wear and aging). Furthermore, changes in dimensions and / or material properties can be used to determine the distance to the ground for landing (as described above in FIG. 33 herein). With regard to pressure, split ring resonators can be used to detect air pressure, air pressure differentials, and / or periodic changes in air pressure. Additionally, with regard to temperature, the split ring resonator can sense the surface temperature as well as the temperature inside the component.

[0341] In this manner, split ring resonators found in or on components throughout the unmanned aerial vehicle 3402 may be used to sense parametric measurements related to the state of health of the unmanned aerial vehicle 3402. Additionally, more than one measurement may be received simultaneously. For example, in response to a wireless ping, each split ring resonator may provide a frequency response. Such frequency response may be calibrated to a measurement of pressure in one example, while another frequency response may be calibrated to changes in material properties in another example. In this manner, responses from all split ring resonators may be received to provide simultaneous results of all sensor parameters associated with the unmanned aerial vehicle 3402.

[0342] 35 illustrates a representation 3500 of a landing position sensor as well as a split-ring resonator disposed in and / or on an air vehicle, according to one embodiment. Optionally, representation 3500 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3500 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0343] As shown, unmanned aerial vehicle 3502 may be capable of vertical takeoff and / or landing (VTOL and / or eVTOL). It should be understood that in other embodiments, unmanned aerial vehicle 3502 may be configured for other takeoff capabilities (e.g., conventional takeoff and landing, short-field takeoff and landing, etc.).

[0344] One or more split resonators may be found on the unmanned aerial vehicle 3502, including disposed on the air vehicle body 3504, structural components 3506, and / or landing gear 3508. Of course, consistent with FIG. 34 , one or more split resonators may be disposed in any location (and within any amount) on the unmanned aerial vehicle 3502 and used to provide sensor-related information.

[0345] As an example, split ring resonators disposed on the unmanned aerial vehicle 3502 may be distributed throughout the surface. Additionally, lightweight antennas may be further distributed throughout the unmanned aerial vehicle 3502. In one embodiment, the split ring resonators and antennas may be redundant (especially for mission-critical components, safety constraints, etc.). Split ring resonators such as these may provide real-time simultaneous sensing (in milliseconds). Furthermore, condition signatures may be associated with simultaneous feedback responses from the split ring resonators. For example, condition signatures may be associated with component failures, external conditions (weather, flight patterns, etc.), etc. Furthermore, the split ring resonators may be positioned to enable triangulation positioning to assist in pinpoint landing (consistent with that described herein with respect to FIG. 33).

[0346] As such, the split ring resonator may include position sensors 3512 and may be used to calculate landing gear flexure 3510, surface flexure 3518, propeller flexure 3514, and / or air pressure 3516. As highlighted elsewhere, the split ring resonator may be used in any capability related to takeoff, flight, landing, management, etc. of the unmanned aerial vehicle 3502, including but not limited to torsion, tire wear, airspeed, air pressure, vehicle component flexure, etc.

[0347] In one embodiment, the position sensor 3512 may operate to pinpoint a location for a precise landing. Additionally, a split ring resonator 3522 disposed within and / or on the surface of the ground 3520 may be used to assist in achieving a precise landing.

[0348] 36A and 36B show two depictions 3600 of a split-ring resonator disposed in and / or on an aircraft, according to one embodiment. Optionally, the two depictions 3600 may be implemented in the context of any one or more of the embodiments described in any of the front and / or back figures and / or descriptions thereof. However, it should be understood that the two depictions 3600 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply to the following description as well.

[0349] As shown, the aircraft 3602 includes one or more split ring resonators located in and / or on various locations on the aircraft 3602, including, but not limited to, the engines 3604 (jet, propeller, etc.), wings 3606, horizontal stabilizers 3608, fuselage 3610, and / or tires 3612. It should be understood that any number of split ring resonators may be found on the aircraft 3602, and the purposes of the split ring resonators may vary. For example, a split ring resonator located at the front of the aircraft 3602 may be used to collect external weather conditions (air pressure, temperature, wind speed, etc.), a split ring resonator located on a tire may be used to determine tread life and condition, and / or a split ring resonator located in the engine may be used to ensure safety and lack of material fatigue. In some embodiments, condition signatures may be created and correlated with known conditions (weather patterns, signatures of material fatigue, etc.). Additionally, frequencies from a split-ring resonator may be used for more than one condition signature simultaneously. For example, a split-ring resonator may be used to determine tread thickness, stiction measurement, hydroplaning detection, etc.

[0350] While the two depictions 3600 show commercial aircraft, it should be understood that any aircraft (civilian, military, personal, etc.) may be applicable. Furthermore, the use of split ring resonators in aircraft may provide millisecond-level changes prior to takeoff, continuously during flight, and continuously during landing. These changes may include changes in structural parameters (e.g., fatigue thresholds, impending component failure, etc.), which may alert systems and personnel. For example, triggering an alert may cause the aircraft to avoid the aircraft or land safely before an impending failure event occurs.

[0351] FIG. 37A shows a representation 3700 of a split-ring resonator disposed in and / or on a rocket, according to one embodiment. Optionally, representation 3700 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3700 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0352] As shown, spacecraft 3702 may include one or more split ring resonators disposed throughout spacecraft 3702, including, but not limited to, wings 3704, elevons 3714, engines 3708, flight deck 3710, and / or cargo bay 3708. It should be understood that any number of split ring resonators may be found on spacecraft 3702.

[0353] The use of split-ring resonators on spacecraft can provide millisecond-level changes before takeoff, continuously during flight, and continuously during re-entry. These changes can include changes in structural parameters (e.g., fatigue thresholds, impending component failure, etc.), which can alert systems and personnel. Additionally, spacecraft (often called orbiters) are often attached to rocket boosters. Generally, a structural failure of any component on either the spacecraft or rocket booster often results in complete failure of both the spacecraft and rocket booster. However, the use of split-ring resonators ensures that any structural parameter changes (to either the spacecraft or rocket booster) are detected before affecting either the spacecraft or rocket booster. In some embodiments, a change in a structural parameter can cause the spacecraft and rocket booster to disengage (based on the identified change in the structural parameter), maintaining one or the other in place.

[0354] 37B shows a representation 3701 of a split-ring resonator disposed in and / or on a rocket and / or landing platform, according to one embodiment. Optionally, representation 3701 may be implemented in the context of any one or more of the embodiments described in any of the preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3701 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0355] As shown, spacecraft 3709 may be attached to rocket booster 3707. Split ring resonators may be located or found on each of spacecraft 3709 and rocket booster 3707. Additionally, launch pads for spacecraft 3709 and rocket booster 3707 are shown, including launch pad platform 3703, flame pit 3711, platform truss 3713, and / or launch pad service structure 3705. Split ring resonators may be located or found throughout each component of the launch pad in depiction 3701. In this manner, split ring resonators located in and / or on portions of the launch pad may be used to detect changes in structural parameters (e.g., fatigue threshold, impending component failure, etc.), which may alert systems and personnel. For example, a structural failure (of any component) may cause the launch to be aborted. Additionally, a structural failure after the launch has begun (but before liftoff) may cause the launch to be aborted. Therefore, any structural failure (at any time) could be grounds for the launch to be aborted and / or corrective measures to be implemented.

[0356] In this manner, an early warning system may be based on split ring resonators found throughout the launch pad, spacecraft, and / or rocket booster, and / or any components associated therewith, and may obtain real-time data to ensure safe remediation of any detected changes.

[0357] Additionally, split ring resonators may be used as low-cost resonant sensors for safety in all types of air vehicles, for example, to detect excessive vibration on a component, to detect and monitor microcracks in a material, to monitor local temperature on the surface of a non-metallic component (providing not only instantaneous values ​​but also historical / cyclical changes), to monitor local temperature within a non-metallic component (providing not only instantaneous values ​​but also historical / cyclical changes), to provide pinpoint positional accuracy (e.g., for precision landings), and / or to be placed within a material, on a surface, and / or below a surface (such as a painted surface).

[0358] 38A is a flowchart 3800 for reporting feedback from a split-ring resonator, according to one embodiment. Optionally, flowchart 3800 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that flowchart 3800 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0359] Flowchart 3800 relates to an embodiment of receiving sensor data from one or more split ring resonators and taking one or more actions in response thereto.

[0360] As shown, flowchart 3800 begins with receiving sensor data from a calibrated sensor (step 3802). The calibrated sensor may include one or more split-ring resonators calibrated based on their natural resonance. It is determined whether the sensor data is within a predetermined range (decision 3804). For example, the sensor data may be correlated with a condition signature (where known deviations are correlated with known faults and / or conditions). If the sensor data is within range (or within an acceptable condition signature), the method returns to continuously receiving sensor data (per step 3802). Of course, the interval at which sensor data is received may be predetermined and / or adjusted as needed.

[0361] If the sensor data is not within range, flowchart 3800 proceeds to decrease the duration of the test interval (step 3806). In one embodiment, step 3806 may be optional. For example, the duration of the test interval may already be approximately continuous (per step 3802), in which case it may not be necessary to decrease the duration of the test interval. In response to (or simultaneously with) step 3806, an alert may be triggered (step 3808) and a report may be generated (step 3810).

[0362] In some embodiments, alerts and / or reports regarding out-of-range sensor data may be used to notify and / or alert a human (e.g., an operator, a supervisor, etc.), may be stored in a repository (e.g., storage, etc.) to notify and / or alert an organization (e.g., Environmental Protection Agency, Department of Motor Vehicles, etc.), etc. It is also envisioned that such out-of-range sensor data may be used to trigger automated action (e.g., an AI integrated system, etc.), cause automated configuration change(s) on the vehicle (or equipment in which the split-ring resonator is located), and / or take any other automated action (without human intervention).

[0363] 38B is a flowchart 3812 for landing an air vehicle and / or drone using a split-ring resonator, according to one embodiment. Optionally, flowchart 3812 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that flowchart 3812 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0364] Flowchart 3812 relates to an embodiment of receiving sensor data from one or more split ring resonators (located at locations) to support pinpoint landing capabilities. It should be understood that a similar flow may be created when using split ring resonators located on an air vehicle (rather than relying on location-based sensors).

[0365] As shown, flowchart 3812 begins with an aerial vehicle approaching a landing site (step 3814). A determination is made as to whether the aerial vehicle is within a set range (e.g., a predetermined distance from a landing pad) (decision 3816). In one embodiment, determining whether the aerial vehicle is within the set range (via decision 3816) may depend at least in part on a split-ring resonator disposed on the aerial vehicle.

[0366] Once the aerial vehicle is within the set range, data may be received from the location sensors (step 3818). Data from these location sensors may be transmitted to the aerial vehicle (decision 3820) that may affect position adjustments. When no further changes to the position are required, the aerial vehicle may be landed (step 3822). Of course, it should be understood that decision 3820 may be made continuously as the aerial vehicle approaches the landing pad so that real-time adjustments can be made to the position of the aerial vehicle.

[0367] In one embodiment, a point sensor (per step 3818) may be used to triangulate the precise location of the air vehicle. As can be appreciated, flowchart 3812 provides just one example of how a split-ring resonator may be used to assist in landing an air vehicle.

[0368] 39 shows a representation 3900 of a metamaterial in a dielectric matrix and associated circuitry, according to one embodiment. Optionally, representation 3900 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 3900 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0369] Within the context of this description, metamaterials may include any material that is engineered to have physical properties not found in naturally occurring materials.

[0370] As shown in SEM image 3902, metamaterials can be tuned within a dielectric matrix. For example, metamaterials can be selected for frequency-selective properties, including cases where the metamaterial is inherently tuned and engineered for the application. In addition, metamaterials can provide frequency-selective conductivity without direct current conductivity. Furthermore, such metamaterials can conduct and maintain connectivity without contact (unlike standard conductive inks / flakes / coatings that require contact to conduct and maintain connectivity).

[0371] The arrangement of tuned metamaterials within the dielectric matrix (via SEM image 3902) can be shown via a lumped circuit 3904 to achieve either a series resistance with a minimum impedance at the resonant frequency, or a parallel resistance with a maximum impedance at the resonant frequency. It should be understood that the arrangement of metamaterials can be arranged in either a series resistance and / or a parallel resistance.

[0372] In various embodiments, the metamaterial in the dielectric matrix may be arranged in a split ring resonator 3906, which may be represented by a circuit-type arrangement 3908. Such an arrangement 3908 may include an inductor associated with the rings and a capacitor associated with the gap of the split ring resonator. Such an arrangement should be interpreted in a manner consistent with FIGS. 24B1 and 24B2 described herein above.

[0373] The use of metamaterials as frequency-selective materials allows for continuous bending without degradation of conductance. Additionally, frequency tuning can increase the signal-to-noise ratio, allowing for better detection and resolution. Furthermore, other parameters (such as temperature, stress, strain, etc.) can be measured directly through the stretching, deformation, and / or temperature readings of the dielectric matrix.

[0374] Thus, metamaterials can be used in and / or on split ring resonators to provide frequency-selective conductivity without DC conductivity. Furthermore, the high frequency conductivity of metamaterials allows for their use in split ring resonators.

[0375] 40 shows a representation 4000 of a split-ring resonator embedded in an open-cell or closed-cell material, according to one embodiment. Optionally, representation 4000 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 4000 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0376] As shown, split ring resonator 4006 may be embedded between first layer 4002 and second layer 4004. In various embodiments, the material of the first and / or second layers may include open-cell or closed-cell (selected or coated) material. Such materials may have a dielectric constant that is a mixture of the material and the air in the pores within the material itself, so that when the airflow is compressed, the foam displaces the air and the strong mass dielectric constant becomes that of the material (open-cell or closed-cell foam). As a result of the fact that the dielectric constant of the material is much higher than that of air, when the material is compressed, the frequency downshifts.

[0377] From an alternative perspective, embedding the split ring resonator 4006 in a foam material allows for a higher resonant frequency (compared to the split ring resonator's response alone), which is at least partially due to deformation of the foam material, which is directly and significantly correlated to the change in the dielectric constant of the foam material as deformation occurs.

[0378] Furthermore, in another embodiment, the split-ring resonator can be printed on the top surface of a foam, either open-cell or closed-cell material, with a ground plane on the back surface and the foam material interposed between the top and ground plane levels. The distance between the front sensor and the ground plane (with the foam interposed between them) can shift the frequency (similar to a capacitor). In this way, the foam material can function as a pressure sensor, and the presence of the foam can act to shift the resonant frequency up or down. For example, if the foam element(s) deform or deflect (pushed in or pulled out), the foam element(s) can be measured as a change in the split-ring resonator.

[0379] Thus, as detailed herein, split-ring resonators can provide a response to wireless pings / chirps / queries. Furthermore, using a foam-based material to encase a split-ring resonator can amplify the split-ring resonator's response. Again, the foam-based material deforms more than, for example, a semi-rigid material, resulting in a larger difference in permittivity (again comparing a foam-based material to a semi-rigid material). Within the context of FIG. 24B4, a foam-based material (where the y-axis coordinate measures permittivity rather than frequency) can have a similar type of response. Furthermore, in one embodiment, such permittivity may be unipolar or bipolar. For example, in some cases (e.g., during turbulent conditions), both positive and negative pressures may exist at a surface. Within the context of this description, a semi-rigid material refers to a rigid material that can bend. A foam-based material refers to a spongy material with cells. Comparing a semi-rigid material to a foam-based material, a foam-based material (due to its spongy morphology) can provide greater compression and deformation. Thus, foam-based materials may be used in combination with split-ring resonators (as detailed herein) to allow for greater amplification of response (which may correlate with instrumentation that can operate at lower frequencies and power levels).

[0380] Therefore, the combination of a split ring resonator with an associated material and / or substrate (e.g., semi-rigid material, foam-based material, concrete, rubber, polymer, etc.) can have an ensemble effect, which, within the context of this description, refers to the frequency response of the combination of a split ring resonator with an associated material and / or substrate.

[0381] 41 shows a representation 4100 of a pressure sensor using open-cell or closed-cell material, according to one embodiment. Optionally, representation 4100 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 4100 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0382] In function, a pulse wave may propagate from an antenna (placed on the vehicle 4104 and / or surrounding objects / locations) and then impinge on an object (e.g., an unoptimized sensor 4104) having real and imaginary physical materials that either reflect or absorb the energy. This may produce a form of analog telemetry via wireless communication (transmission of temperature, pressure, and / or other measurements may occur via reflection or absorption of the pulse wave), resulting in low cost remote sensing of parameters of the physical world.

[0383] A real-world test of a vehicle 4102 with sensory data is shown in FIG.

[0384] 42 shows a representation 4200 of wind pressure sensing data using open-cell or closed-cell material, according to one embodiment. Optionally, representation 4200 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 4200 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0385] As shown, depiction 4200 is of wind pressure sensing data based on a vehicle (such as vehicle 4102). The wind pressure sensor may be constructed in a manner consistent with FIG. 40. Furthermore, it should be understood that FIG. 42 represents a single use case (wind pressure) scenario. Similar sensing data may be obtained for other metrics (such as temperature, pressure, speed, etc.).

[0386] Representation 4200 shows three case scenarios: (1) frequencies based on no vehicle motion, (2) frequencies based on vehicle straight-track acceleration, and (3) frequencies based on the vehicle decelerating in a curve. As can be observed, each case scenario produces a distinct frequency measurement. Such frequency measurements can be correlated with state signatures, as described herein above. Additionally, stars on each line indicate maximum / minimum data points.

[0387] 43 shows a representation 4300 of paths and circuits for frequency-selective conductivity, according to one embodiment. Optionally, representation 4300 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that representation 4300 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply equally to the following description.

[0388] As shown, depiction 4300 includes image 4301 of a current carrying material 4302 and a metamaterial 4304. As can be observed, current carrying materials require DC current based on direct connections to allow current to flow. Current carrying materials such as these may be represented by circuit 4306. In contrast to conventional systems such as these, metamaterial 4304 may be used to achieve conductivity through resistive and reactive pathways. Paths such as these may be based on non-direct connections (paths and / or nodes need not be in contact) to be conductive. Circuit 4308 represents the use of metamaterials to establish conductivity.

[0389] 44 shows a depiction 4400 of a number of industries in which the use of split-ring resonators is applicable, according to one embodiment. Optionally, depiction 4400 may be implemented in the context of any one or more of the embodiments described in any preceding and / or following figure(s) and / or their description. However, it should be understood that depiction 4400 may be implemented in the context of any desired environment. Additionally, the foregoing definitions may apply to the following description as well.

[0390] As shown, depiction 4400 includes a variety of exemplary global industrial applications where resonant frequency shifts associated with split ring resonators(s) can provide early detection capabilities for literally hundreds of potential scenarios, thereby providing the ability to repair and adjust if potential problems are identified. Data related to resonant frequency shifts of split ring resonators(s) can be applied to nearly every industry and market, including, but not limited to, utilities, space travel and exploration, agriculture, power generation, manufacturing, vehicle safety, commercial tire dynamics, professional sports, forging, construction, molecular analysis and decomposition, biomedicine, battery composition, aviation and / or aviation, navigation, consumer goods, bridges and roads, etc. Some of these industries (and applicability of split ring resonators) are described in detail herein.

[0391] For the purposes of being as precise as possible, but also to demonstrate the potential applicability of the use of split ring resonators (and the associated resonant frequency shifts) to many other industries, additional material is provided below.

[0392] As mentioned above, split ring resonators may be embedded in or printed on other materials (other than the concrete barriers of FIG. 22A2 and / or the metal barriers of FIG. 22A3 ) that encompass a wide range of applications and, similarly, a wide range of global industries. In this manner, measuring resonant frequency shifts can be performed in nearly any application in which split ring resonators can be embedded or printed (on a surface, within a material, etc.). Furthermore, split ring resonators can be used not only to determine a shift in resonant frequency (which can be associated with a signature indicative of a physical condition), but also to control aspects in response to receiving such input. For example, a temperature sensor may have a split ring resonator embedded therein such that, upon reaching a predetermined temperature, it may activate an external unit (such as an air conditioner, heater, or vent) until the ambient temperature reaches the predetermined temperature. In some cases, taking action may rely on a processor that can interpret data from the resonant frequency shift of the split ring resonator and, in response, initiate an action (e.g., a command to take action to change environmental conditions, etc.). In other embodiments, actions may be taken without the use of an external processor. For example, an item may be transported that must be kept within a predetermined temperature. A temperature sensor with an embedded split ring resonator may be affixed to the item to determine temperature integrity testing while the item is being transported; if the temperature exceeds a predetermined threshold, deformation of the sensor may produce a physical symptom (such as a color change or indicator deformation). In this way, environmental changes or symptoms may be directly related to the state of the split ring resonator.

[0393] In one embodiment, aviation-related applications may include detecting material stress, temperature, or vibration levels approaching or exceeding known tolerances as aircraft undergo subsonic, transonic, supersonic, and hypersonic speeds. Using split-ring resonators in and on wing surfaces, including aileron(s), elevator(s), and rudder(s), may detect air pressure both above and below the wing surface, temperature drops and increases, surface area distortion, and even potential material failure or failure, providing an opportunity to warn both pilots and ground crews of potential danger to the aircraft, providing sufficient time to correct, depending on airspeed, lift, flight attitude, payload distribution, etc., before any catastrophic event occurs. Additionally, applicable embodiments may include fixed-wing structures coupled with airfoil blades, using split-ring resonators in and on them to measure air pressure above and below the airfoil surface and determine the optimal extension or retraction of the airfoil, thereby providing an opportunity to adjust flight parameters and maximize aircraft performance. In another aviation embodiment, split-ring resonators may be used in and on wing surfaces, including aileron(s), elevator(s), and rudder(s), to detect when the harmonics or geometry of the wing surface begin to deform, turning smooth air into turbulence...

Claims

1. An adhesive, at least one mesoscale or microscale resonator embedded within a material that constitutes at least a portion of the adhesive, the at least one mesoscale or microscale resonator being formed from a composite material; the at least one mesoscale or microscale resonator comprises a plurality of first carbon particles, the plurality of first carbon particles configured to uniquely resonate in response to an electromagnetic ping based at least in part on a concentration level within the at least one mesoscale or microscale resonator.

2. The adhesive of claim 1 , wherein the at least one mesoscale or microscale resonator comprises at least one split ring resonator (SRR).

3. The adhesive of claim 1 , wherein the resonance is an electromagnetic return signal indicative of a state of the at least one mesoscale or microscale resonator.

4. The adhesive of claim 3 , wherein the condition of the at least one mesoscale or microscale resonator is indicative of at least one of exposure to an analyte, exposure to a biological material, or exposure to radiation.

5. 4. The adhesive of claim 3, wherein the state of the at least one mesoscale or microscale resonator is correlated to indicate a maximum value of at least one of exposure to an analyte, exposure to a biomaterial, or exposure to radioactivity.

6. The adhesive of claim 3 , wherein the condition comprises absorption or adsorption into the material.

7. 10. The adhesive of claim 1, wherein the adhesive is configured to resonate at a first frequency in response to the electromagnetic ping when the material is in a first state and to resonate at a second frequency in response to the electromagnetic ping when the material is in a second state.

8. 8. The adhesive of claim 7, wherein the adhesive is configured to indicate a degree of adhesion to the material by generating a first electromagnetic return signal in response to the electromagnetic ping, and to indicate a lack of adhesion to the material by generating a second electromagnetic return signal in response to the electromagnetic ping.

9. 3. The adhesive of claim 2, wherein the first set of one or more SRRs comprises a plurality of first carbon particles, the plurality of first carbon particles configured to uniquely resonate in response to the electromagnetic ping based at least in part on a sensed concentration level of a first analyte.

10. 10. The adhesive of claim 9, wherein the second set of one or more SRRS comprises a plurality of second carbon particles, the plurality of second carbon particles configured to uniquely resonate in response to the electromagnetic ping based at least in part on a concentration level of a second analyte.

11. each first carbon particle of the plurality of first carbon particles and the second carbon particle are chemically bonded to the material; each first carbon particle of the plurality of first carbon particles includes a first aggregate that forms a first porous structure; or the second carbon particles include second aggregates that form a second porous structure; The adhesive of claim 10, wherein the adhesive is at least one of:

12. The adhesive of claim 1 , wherein at least three instances of the adhesive are used to triangulate the position of the adhesive.

13. 10. The adhesive of claim 1, wherein the adhesive is configured to be applied to one of a vertical take-off and landing (VTOL) aircraft, an electric vertical take-off and landing (eVTOL) aircraft, a drone, a passenger drone, a commercial aircraft, a military aircraft, a vehicle, a robot, a body, a box, a personal electronic device, a toolbox, a consumer electronics product, or a rocket.

14. The adhesive of claim 1 , wherein the composite material comprises 3D monolithic carbon growth.

15. 15. The adhesive of claim 14, wherein the tuned resonant frequency of the 3D monolithic carbon growth is based at least in part on one or more physical properties of the material.

16. 15. The adhesive of claim 14, wherein the resonant frequency of the 3D monolithic carbon growth is based at least in part on one or both of the permittivity and permeability of the material.

17. The adhesive of claim 3 , wherein the electromagnetic return signal has a first frequency and the second electromagnetic return signal has a second frequency different from the first frequency.

18. The adhesive of claim 1 further comprising a protective layer on the material.

19. The adhesive of claim 1 , wherein the at least one mesoscale or microscale resonator comprises an array of two or more split-ring resonators.

20. 20. The adhesive of claim 19, wherein each split ring resonator of the array is configured to sense at least one of a specific predetermined analyte, a biological agent, a radioisotope, or a specific predetermined volatile substance.

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