Energy harvesting module and method of manufacturing energy harvesting module

Abstract

Energy harvesting modules, and more particularly, energy harvesting modules configured to be coupled to a rotatable assembly of a wheel of a vehicle, and methods of manufacturing energy harvesting modules are disclosed. In some embodiments, an energy harvesting system includes a piezoelectric component configured to generate energy in response to a mechanical strain imparted on the piezoelectric component, where the piezoelectric component is configured to deform when experiencing a mechanical strain, and where the piezoelectric component is configured to generate energy in response to a mechanical strain imparted on the piezoelectric component. And the piezoelectric component comprises a layer of piezoelectric material, one or more conductive bonding layers, a load backing layer and one or more electrode layers, wherein the load backing layer comprises a fiber reinforced composite material.

Description

Technical Field

[0001] The present application relates generally to energy harvesting modules and, more particularly, to energy harvesting modules configured as rotatable components coupled to wheels of a vehicle. Background Art

[0002] In the field of automotive sensor systems, the need for advanced sensing applications that complement existing electronic safety systems has attracted considerable attention. This includes, for example, measuring temperature, pressure, acceleration, and forces (static and dynamic) acting on tires, wheels, and cars. All of these sensors cause increased power requirements to operate and transmit data more frequently. Current power sources that drive these sensors (e.g., lithium-ion batteries) are limited in their capacity and exhibit disadvantages such as low durability, difficulty in replacement, and most notably, poor sustainability in terms of environmental impact. As the power load increases, these power sources are further affected by accelerated discharge cycles, resulting in frequent or premature replacement of the entire sensor module. This can increase the user's total cost of ownership and maintenance.

[0003] The foregoing examples of the related art and limitations associated therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent upon reading the specification and studying the drawings. Summary of the invention

[0004] The exemplary embodiments disclosed herein are intended to solve problems related to one or more problems existing in the prior art, as well as to provide additional features that will become apparent by reference to the following detailed description when combined with the accompanying drawings. According to various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are given as examples and not limitations, and it will be apparent to those of ordinary skill in the art who read this disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the invention.

[0005] In certain embodiments, an energy harvesting module includes: a piezoelectric component configured to generate energy in response to a mechanical strain imparted on the piezoelectric component, wherein the piezoelectric component is configured to deform when subjected to the mechanical strain, and the piezoelectric component includes a piezoelectric material layer, one or more conductive bonding layers, a load backing layer, and one or more electrode layers, wherein the load backing layer includes a fiber-reinforced composite material.

[0006] In some embodiments, the one or more electrode layers include a first electrode layer, and the one or more conductive bonding layers include a first conductive bonding layer, wherein the first conductive bonding layer is vertically above and in direct contact with the load backing layer, and the piezoelectric material layer is vertically above and in direct contact with the first conductive bonding layer, and the piezoelectric material layer is horizontally surrounded by the first electrode layer.

[0007] In some embodiments, the fiber-reinforced composite material includes at least one of the following: a carbon fiber composite material, a glass fiber composite material, a carbon nanotube reinforced composite material, a graphene reinforced composite material, and a ceramic matrix composite material. In some examples, the fiber-reinforced composite material is in direct contact with the first conductive bonding layer by removing a surface layer of the fiber-reinforced composite material, wherein removing the surface layer includes mechanical etching, ablation, chemical etching, polishing, or laser etching processes.

[0008] In certain embodiments, the fiber reinforced composite material comprises an elastic modulus, wherein the elastic modulus after removing the surface layer is higher than the elastic modulus before removing the surface layer.

[0009] In some embodiments, the one or more electrode layers include a second electrode layer, the one or more conductive bonding layers include a second conductive bonding layer, wherein the second conductive bonding layer is vertically above the piezoelectric material layer and in direct contact with the piezoelectric material layer, and the second electrode layer is vertically above the second conductive bonding layer and in direct contact with the second conductive bonding layer. In some examples, the one or more conductive bonding layers include metal powder and resin.

[0010] In certain embodiments, an energy harvesting module includes a piezoelectric component configured to generate energy in response to a mechanical strain imparted on the piezoelectric component, wherein the piezoelectric component is configured to deform when subjected to the mechanical strain, and the piezoelectric component includes a piezoelectric material layer, one or more conductive bonding layers, a load backing layer, one or more electrode layers, and one or more metal layers, wherein the load backing layer includes a fiber reinforced composite material.

[0011] In some embodiments, the one or more metal layers include a first metal layer, the one or more electrode layers include a first electrode layer, and the one or more conductive bonding layers include a first conductive bonding layer, wherein the first conductive bonding layer is vertically above the load backing layer and in direct contact with the load backing layer, the first metal layer is vertically above the first conductive bonding layer and in direct contact with the first conductive bonding layer, wherein the first metal layer is electrically connected to the first conductive bonding layer, and the piezoelectric material layer is vertically above the first metal layer, and the piezoelectric material layer is horizontally surrounded by the first electrode layer.

[0012] In some embodiments, the piezoelectric component also includes one or more interface layers, wherein the one or more interface layers include a first interface layer, wherein the first interface layer is vertically above and in direct contact with the first metal layer, and the piezoelectric material layer is vertically above and in direct contact with the first interface layer.

[0013] In certain embodiments, the one or more metal layers include a second metal layer, the one or more electrode layers include a second electrode layer, and the one or more conductive bonding layers include a second conductive bonding layer, wherein the second metal layer is vertically above the piezoelectric material layer.

[0014] In some embodiments, the second conductive bonding layer is vertically above the second metal layer and directly contacts the second metal layer, wherein the second conductive bonding layer is electrically connected to the second metal layer.

[0015] In certain embodiments, the one or more interface layers include voids.

[0016] In some embodiments, a method includes: forming a load backing layer including a fiber reinforced composite material, forming a conductive bonding layer, forming a piezoelectric material layer including a piezoelectric body, forming an electrode layer, sintering the piezoelectric body in the piezoelectric material layer, applying a composite paste on the piezoelectric body to form an interface layer, drying the piezoelectric body, applying a metal paste on the composite paste to form a metal layer, and sintering the metal layer and the composite paste, removing a surface layer of the fiber reinforced composite material by a mechanical etching process, ablation, chemical etching, or laser etching process, stacking the conductive bonding layer on the load backing layer, stacking the piezoelectric body having the metal layer on the conductive bonding layer, and stacking the electrode layer on the conductive bonding layer to surround the piezoelectric material layer. In some embodiments, the surface layer includes a resin layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various exemplary embodiments of the present invention are described in detail below with reference to the following drawings. The drawings are provided for illustrative purposes only and depict only exemplary embodiments of the present invention. These drawings are provided to facilitate the reader's understanding of the present invention and should not be construed as limiting the breadth, scope or applicability of the present invention. It should be noted that for clarity and ease of description, these drawings are not necessarily drawn to scale.

[0018] Figure 1 is a diagram of a smart wheel sensor system integrating at least one smart wheel according to various embodiments.

[0019] Figure 2is a block diagram of an exemplary computing device in accordance with various embodiments.

[0020] Figure 3A is a perspective view of a smart wheel according to various embodiments.

[0021] Figure 3B is a perspective view of a smart wheel without a flexible component according to various embodiments.

[0022] Figure 4A is a perspective view of an energy harvester according to various embodiments.

[0023] Figure 4B is a top view of an energy harvester according to various embodiments.

[0024] Figure 4C is a front view of an energy harvester according to various embodiments.

[0025] Figure 4D is a rear view of an energy harvester according to various embodiments.

[0026] Figure 4E is a bottom view of an energy harvester according to various embodiments.

[0027] Figure 4F is a right side view of an energy harvester according to various embodiments.

[0028] Figure 4G is a left side view of an energy harvester according to various embodiments.

[0029] Figure 5A is a side cross-sectional view of an energy harvester with a piezoelectric assembly in an unbiased state according to various embodiments.

[0030] Figure 5B is a side cross-sectional view of an energy harvester with the piezoelectric assembly 404 in a biased state according to various embodiments.

[0031] Figure 6 is a perspective view of an integrated energy harvester according to various embodiments.

[0032] Fig. 7A Another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0033] Figure 7B Illustrated are top views of a CFC material having a surface layer and a CFC material with the surface layer removed according to various embodiments.

[0034] Fig. 8A Yet another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0035] Figure 8BIllustrated is a cross-sectional view of a piezoelectric assembly according to an embodiment of the present disclosure.

[0036] Fig.9A Still another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0037] Fig. 9B Another cross-sectional view of a piezoelectric assembly is illustrated according to an embodiment of the present disclosure.

[0038] Fig. 10A Still another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0039] Fig. 10B Yet another example of a cross-sectional view of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0040] Fig.11A Still another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0041] Fig. 11B Still another example of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0042] Fig. 11C Still another example of a cross-sectional view of a piezoelectric assembly according to an embodiment of the present disclosure is illustrated.

[0043] Fig.12 Illustrate improved power generation using carbon fiber composite materials compared to steel materials according to various embodiments.

[0044] Fig.13 is a flow chart of an energy harvester process according to various embodiments.

[0045] Fig.14 An example method for preparing a piezoelectric component according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0046] Various exemplary embodiments of the present invention are described below with reference to the accompanying drawings to enable those of ordinary skill in the art to implement and use the present invention. As will be apparent to those of ordinary skill in the art after reading this disclosure, various changes or modifications may be made to the examples described herein without departing from the scope of the present invention. Therefore, the present invention is not limited to the exemplary embodiments and applications described and illustrated herein. In addition, the specific order or hierarchy of the steps in the methods disclosed herein are merely exemplary approaches. Based on design preferences, the specific order or hierarchy of the steps of the disclosed methods or processes may be rearranged while remaining within the scope of the present invention. Therefore, it will be understood by those of ordinary skill in the art that the methods and techniques disclosed herein present various steps or actions in a sample order, and unless otherwise expressly stated, the present invention is not limited to the specific order or hierarchy presented.

[0047] As described above, batteries or other disposable energy sources that power vehicle sensor systems are limited in their capacity and exhibit disadvantages such as low durability, difficulty in replacement, and poor environmental sustainability. An alternative to disposable batteries in vehicle sensor systems involves harvesting energy from the environment. Thus, according to various embodiments, new systems and methods for harvesting energy from the environment near the wheel using energy harvesters are disclosed herein. According to various embodiments, these energy harvesters can be devices that convert energy from various sources such as kinetic energy, thermal energy, light, and / or mechanical energy into usable electrical energy. For example, an energy harvester can utilize piezoelectric transduction to convert tire deformation into electrical energy. The amount of this energy conversion can vary based on the rotational speed of the wheel (e.g., the speed of the car determined by the driver). In addition, in some embodiments, the energy harvester can be placed on the rim of the wheel to capture energy more efficiently.

[0048] In various embodiments, the energy harvester can generate a continuous output at different vehicle speeds based on the weight of the vehicle acting on the underlying surface (e.g., a road) through the rim and tire. For example, a vehicle can have a wheel (e.g., a wheel with a pneumatic tire). A wheel with a pneumatic tire and a rigid rim can exchange vehicle actions along the bead area of ​​the tire that is connected to the rigid rim through an interface. These vehicle actions may include traction, braking, steering, load support, etc. As the wheel rotates, the lower portion of the tire may apply forces in the bead area to offset the weight of the car. These forces may cause the sidewall of the wheel to flex due to the internal air pressure of the tire (e.g., due to the close contact between the rubber tire and the metal rim).

[0049] In various embodiments, the energy harvester may include a substrate and a piezoelectric component. The substrate may be placed behind (e.g., near) the piezoelectric component to form a cavity that allows forces during movement of the vehicle (e.g., wheel rotation) to displace (e.g., strain or bend) the piezoelectric component and generate charge (e.g., electrical energy). The energy harvester, which is a piezoelectric-substrate assembly, may then be arranged around the circumference of the rim, thereby generating continuous power as the wheel rotates. In certain embodiments, when the energy harvester is mounted on the rim of the wheel, the energy harvester may be separated from the rim and / or the tire. Thus, when the tire is changed, the energy harvester does not need to be replaced or changed. The energy harvester may also be coupled to an energy storage device (e.g., a rechargeable battery) to provide a charging cycle that can power a sensor array placed in, on, or near the wheel.

[0050] In some embodiments, the piezoelectric assembly can utilize strain (e.g., mechanical strain indicating relative motion / deflection) to generate charge. In addition, the substrate can be configured to facilitate expression of strain (e.g., relative motion / deflection) of the piezoelectric assembly when placed between the tire and rim of a wheel.

[0051] In various embodiments, the substrate may include a geometry and be located in a power-intensive area of ​​the wheel to increase strain (e.g., energy generation) from the piezoelectric assembly mounted on the substrate. In other words, the energy harvester may be a mechanism with specific internal and external geometry located between the wheel and tire that converts mechanical force (vehicle weight) and motion into usable strain generated on the piezoelectric assembly.

[0052] In certain embodiments, the energy harvester can harvest energy from mechanical loads applied to the wheel. For example, in the presence of a mechanical substrate, the load of the vehicle and the forces applied by the vehicle may induce strain on the piezoelectric component, which generates a large amount of electricity that can be harnessed to power electronic or sensing systems in the vehicle and / or wheel.

[0053] In some embodiments, such an energy harvester including a piezoelectric assembly and a substrate can be modular and scalable for various wheel diameters, energy requirements, and sensor locations. In other embodiments, such a substrate can surround and protect the piezoelectric assembly and other electronics mounted on the substrate from degradation due to exposure. In still other embodiments, the energy harvester can include a piezoelectric assembly and a region of the wheel (e.g., a staging surface) configured or constructed to induce strain on the piezoelectric assembly.

[0054] In various embodiments, the substrate may include a three-dimensional curved bottom surface connected to the rim (e.g., a rotatable component of the wheel that is separated from the tire (e.g., a flexible component) of the wheel) by an interface. The three-dimensional curved bottom surface may include a compound curve in three dimensions (e.g., length, height, and width). Each of the length, height, and width may define a dimension or axis that is orthogonal to each other in a three-dimensional physical space. For example, the length may be along an axis orthogonal to the height, the height may be along an axis orthogonal to the width, and the width may be along an axis orthogonal to the length. In some embodiments, the length, height, and width may be referred to as the x-axis, z-axis, and y-axis. In addition, the substrate may include a two-dimensional (e.g., two of the length, height, and width) curved segmented surface (e.g., a microcavity or depression) opposite to the bottom surface of the substrate. In some embodiments, the two-dimensional curved segmented surface may be curved in a convex or concave manner, and the piezoelectric component may generate strain to deform and conform to the two-dimensional curved segmented surface. Thus, the rectangular piezoelectric component can be configured to bend and conform to a two-dimensional curved segmented surface when seated on the rim via a three-dimensional curved bottom surface (e.g., by being fixed on a substrate having a three-dimensional curved bottom surface).

[0055] In some embodiments, the piezoelectric assembly can be formed of multiple layers. For example, the piezoelectric assembly can include a load backing layer. The load backing layer can include, for example, a fiber reinforced composite material having sufficient load flexibility to hold the piezoelectric assembly together. The piezoelectric assembly can also include a central piezoelectric material layer, which can be configured to generate an electric charge when it is mechanically deformed. The piezoelectric assembly can also include an electrode layer, which can be formed into a grid structure with the central piezoelectric material layer to more effectively collect charge from the central piezoelectric material layer. In a particular embodiment, the electrode layer can include an electrode embedded in a flexible material (e.g., epoxy resin) (e.g., held in a fixed position by the flexible material) and in direct or indirect contact with the piezoelectric material layer.

[0056] In some embodiments, the electrode layer may include a flexible interconnect having electrodes. In addition, the electrode layer may include a flexible material that holds the electrodes and the flexible interconnect in place. The flexible interconnect may be configured to electrically connect the electrodes in the electrode layer to other electrical components (e.g., a pressure sensor) coupled to the wheel to provide power to the other electrical components or for the other electrical components to perform measurements based on signals received from the flexible interconnect.

[0057] In some embodiments, the piezoelectric assembly includes two electrode layers, a piezoelectric material layer, two conductive bonding layers, a load backing layer, and wires connected to a first electrode layer of the two electrode layers. The second electrode layer of the two electrode layers can be used to indirectly contact the piezoelectric material layer to collect charge from the piezoelectric material layer. In some embodiments, the two electrode layers can represent different circuits with different potentials, so that there is a potential difference between the two electrode layers. The potential difference between the two electrode layers can then be used to provide power to the devices of the smart wheel sensor system through the wires. In some embodiments, the piezoelectric material layer is surrounded by the first electrode layer, and there is a gap between the inner peripheral edge of the first electrode layer and the outer peripheral edge of the piezoelectric material layer to prevent a short circuit between the piezoelectric material layer and the first electrode layer. In some embodiments, the gap is 100 μm or greater.

[0058] In various embodiments, the piezoelectric assembly may be adapted to produce strain (e.g., produce energy) in any type of wheel that applies a force (e.g., produces strain) during rotation. Examples of different types of wheels may include wheels with pneumatic tires, wheels with airless tires (e.g., non-pneumatic tires or flat tires), cylindrical wheels, and spherical wheels. In further embodiments, the piezoelectric assembly may be adhered directly to the wheel (e.g., without a substrate) to induce strain and deform along with the portion of the wheel that can deform in response to a load. For example, the piezoelectric assembly may be adhered along the outer surface of a spherical tire, along the spokes of an airless tire, or to any other component of the wheel that can deform in response to a load.

[0059] Although some embodiments may refer to a piezoelectric assembly having a specific number of layers in a specific order, it can be noted that in various embodiments, the piezoelectric assembly can include any number of layers in any order as desired for different applications. For example, the piezoelectric assembly can include four layers, wherein the load backing layer is connected to the upper electrode layer, the upper electrode layer is connected to the piezoelectric material layer, and the piezoelectric material layer is connected to the lower electrode layer.

[0060] In various embodiments, an energy harvester may be part of a smart wheel sensor system to provide power to at least one sensor of the smart wheel sensor system. For example, the energy harvester may be arranged on a wheel of a vehicle (e.g., an object driven by a wheel) along with other sensors of the smart wheel sensor system. The smart wheel sensor system may include multiple types of sensors, each of which may be configured to collect different types of smart wheel sensor system data. For example, the smart wheel sensor system may include an altitude sensor configured to generate air pressure sensor data; an acoustic sensor configured to generate acoustic sensor data; an image sensor configured to generate image sensor data; a gas sensor configured to generate gas sensor data; a magnetic sensor configured to generate magnetic sensor data; an accelerometer sensor configured to generate acceleration sensor data; a gyroscope sensor configured to generate gyroscope sensor data; and a humidity sensor configured to generate humidity sensor data. The smart wheel sensor system data generated by the smart wheel sensor system may be analyzed centrally and locally at a vehicle that relies on the smart wheel for movement (e.g., by a computer or server within or supported by the body of the vehicle) to determine the status of the vehicle and / or individual smart wheels. Advantageously, the smart wheel sensor system may be implemented in an autonomous vehicle, such as part of a backup sensor system, to enhance the safety system of the autonomous vehicle. In various embodiments, an individual wheel on which the device of the smart wheel sensor system is arranged may be referred to as a smart wheel.

[0061] Figure 1 is a diagram of a smart wheel sensor system 100 integrated with at least one smart wheel 102 according to various embodiments. The smart wheel sensor system 100 may include a local sensor system 104 (e.g., a local smart wheel sensor system) having a device platform 106 disposed on a corresponding smart wheel 102. The device platform 106 may represent a device on the smart wheel, such as an energy harvester and / or a sensor powered by the energy harvester.

[0062] The local sensor system 104 may include a local smart wheel server 108 that communicates with sensors within the device platform 106. Thus, each device platform 106 may include at least one sensor and may also include auxiliary interfaces, such as communication interfaces, for communication with the local smart wheel server 108. The local smart wheel server 108 may also communicate with a local smart wheel data repository 110 and any local user devices 112, such as smart phones. For ease of explanation, the term "local" may refer to devices that are bound within or on the body 114 of the vehicle 116 or the smart wheel 102.

[0063] In contrast, the term "remote" may refer to a device located external to the body 114 of the vehicle 116 or the smart wheel 102. For example, the local smart wheel server 108 may be configured to communicate with a remote network 120, such as the Internet. The remote network 120 may also connect the local smart wheel server 108 with a remote server 122 or a remote user device 126, and the remote server 122 may communicate with a remote data repository 124. In addition, the local smart wheel server 108 may communicate with external sensors or devices, such as a remote satellite 128 for global positioning system (GPS) information.

[0064] In various embodiments, at least some of the devices of the device platform 106 may be configured to communicate with the local smart wheel server 108 via a communication interface. The communication interface may enable the devices to communicate with each other using any communication medium and protocol. Thus, the communication interface 280 may include any suitable hardware, software, or combination of hardware and software that can couple the device platform 106 with the local smart wheel server 108. The communication interface may be arranged to operate using any suitable technology for controlling information signals using a set of desired communication protocols, services, or operating procedures. The communication interface may include a suitable physical connector for connecting to the corresponding communication medium. In some embodiments, the communication interface may be separated from a controller area network (CAN) bus. For example, the communication interface may facilitate wireless communication within the local sensor system 104 (e.g., between the device platform 106 and the local smart wheel server 108). Further discussion of such communication interfaces is provided in more detail below.

[0065] In some embodiments, at least some of the devices of the device platform 106 may be configured to communicate with the remote network 120. For example, sensor data generated by sensors of the device platform 106 may be transmitted to a remote server 122, a remote data repository 124, a remote user device 126, and / or a remote satellite 128 via the remote network 120. In various embodiments, some of the devices of the device platform 106 may communicate directly with the remote network 120. For example, some of the devices of the device platform 106 may include a communication interface (discussed further below) that may be configured to communicate directly with the remote network 120 in a manner that bypasses the local server 108. In other embodiments, some of the devices of the device platform 106 may communicate indirectly with the remote network 120. For example, some of the devices of the device platform 106 may include a communication interface (discussed further below) that may be configured to communicate indirectly with the remote network 120 via the local server 108, which includes one or more communication interfaces (discussed further below) that communicate with external devices via various communication protocols (e.g., LTE, 5G, etc.), as discussed in further detail below.

[0066] These communications from the device platform 106 to the remote server 122, whether direct or indirect, may include sensor data collected by the device platform for analysis by the remote server 122. According to various embodiments, the sensor data may be analyzed by the remote server 122 to determine actions that may be performed by the local server 108. For example, as discussed in further detail below, the sensor data may be used to determine parameter values. Then, based on the state of the parameter value, certain actions may be performed, such as in response to the parameter value meeting certain thresholds (e.g., an alert or notification presented via a user interface). This determination of the parameter value may be performed at the remote server 122, and then the parameter value is transmitted to the local server 108 to determine the action to be performed based on the state of the parameter value. In other embodiments, both the determination of the parameter value and the determination of the resulting action may be performed by the remote server 122. Then, the remote server 122 may transmit an indication of the action to be performed to the local server 108 for implementation (e.g., as an instruction to the local server 108 for implementation). Although some embodiments describe the sensor data as being transmitted to a remote server for processing, according to various embodiments, the sensor data may be processed in other ways as needed for different applications. For example, the sensor data may be processed locally at the local server 108, with or without additional input provided from the remote server 122, the remote user device 126, and / or the remote satellite 128, as discussed further below. In some embodiments, the device platform 106 may communicate directly with the user device 112 (e.g., a smart phone), which may then communicate directly or indirectly with the local server 108, the remote network 120, the remote user device 126, and / or the remote satellite 128. In further embodiments, the wheel 102 (e.g., acting as an antenna) and / or the sensor platform 106 may have a direct communication link with the remote user device 126 or the remote satellite 128 (e.g., for the purpose of Internet access and / or GPS applications).

[0067] Figure 2 2 is a block diagram of an exemplary computing device 200 according to various embodiments. As described above, the computing device 200 may represent a computer system as described above in conjunction with Figure 1 Exemplary components of a particular local smart wheel server 108, local user device 112, remote server 122, remote user device 126, certain devices of device platform 106 (e.g., sensors of the device platform), or remote satellite 128 are discussed. Return to Figure 2In some embodiments, the computing device 200 includes a hardware unit 225 and software 226. The software 226 may run on the hardware unit 225 (e.g., a processing hardware unit) so that various applications or programs may be executed on the hardware unit 225 through the software 226. In some embodiments, the functionality of the software 226 may be implemented directly in the hardware unit 225 (e.g., as a system on a chip, firmware, a field programmable gate array (“FPGA”), etc.). In some embodiments, the hardware unit 225 includes one or more processors, such as a processor 230. In some embodiments, the processor 230 is an execution unit or “core” on a microprocessor chip. In some embodiments, the processor 230 may include a processing unit, such as, but not limited to, an integrated circuit (“IC”), an application specific integrated circuit (ASIC), a digital signal processor (DSP), an additional support processor (ASP), a microcomputer, a programmable logic controller (“PLC”), and / or any other programmable circuit. Alternatively, the processor 230 may include multiple processing units (e.g., in a multi-core configuration). The above examples are merely exemplary and are not intended to limit the definition and / or meaning of the term “processor” in any way. The hardware unit 225 also includes a system memory 232 coupled to the processor 230 via a system bus 234. The memory 232 may be a general purpose volatile RAM. For example, the hardware unit 225 may include a 32-bit microcomputer with a 2Mbit ROM and a 64Kbit RAM and / or several GB of RAM. According to various embodiments, the memory 232 may also be a ROM, a network interface (NIC), or any combination of known volatile and / or non-volatile memory devices having appropriate capacity for various desired applications.

[0068] In some embodiments, the system bus 234 can couple each of the various system components together. It should be noted that the term "coupling" as used herein is not limited to direct mechanical, communication and / or electrical connections between components, but can also include indirect mechanical, communication and / or electrical connections between two or more components or couplings that can be operated through intermediate elements or spaces. The system bus 234 can be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus or external bus, and / or a local bus using any of a variety of available bus architectures, including but not limited to a 9-bit bus, an industry standard architecture (ISA), a microchannel architecture (MSA), an extended ISA (EISA), an intelligent drive electronics (IDE), a VESA local bus (VLB), a peripheral component interconnect card international association bus (PCMCIA), a small computer interface (SCSI) or other proprietary bus, or any custom bus suitable for computing device applications.

[0069] In some embodiments, computing device 200 may optionally further include at least one media output component or display interface 236 for presenting information to a user. Display interface 236 may be any component capable of conveying information to a user, and may include, but is not limited to, a display device (not shown) (e.g., a liquid crystal display (“LCD”), an organic light emitting diode (“OLED”) display, or an audio output device (e.g., a speaker or headphones). In some embodiments, computing device 200 may provide at least one desktop interface, such as desktop 240. Desktop 240 may be an interactive user environment provided by an operating system and / or applications running within computing device 200, and may include at least one screen or display image, such as display image 242. Desktop 240 may also accept input from a user in the form of device input, such as keyboard and mouse input. In some embodiments, desktop 240 may also accept simulated input, such as simulated keyboard and mouse input. In addition to user input and / or output, desktop 240 may also send and receive device data, such as input and / or output to a flash device or local printer local to the user.

[0070] In some embodiments, computing device 200 includes an input device or user interface 250 for receiving input from a user. User interface 250 may include, for example, a keyboard, a pointing device, a mouse, a stylus, a touch-sensitive panel (e.g., a touchpad or touch screen), a position detector, and / or an audio input device. A single component such as a touch screen may function as both an output device and an input interface for a media output component. In some embodiments, a mobile device such as a tablet computer may be used.

[0071] In some embodiments, computing device 200 may include a database 260 as a data repository within memory 232, such that various information may be stored within database 260. Alternatively, in some embodiments, database 260 may be included within a remote server (not shown) having file sharing capabilities, such that computing device 200 and / or remote end users may access database 260. In some embodiments, a plurality of computer executable instructions may be stored in memory 232, such as one or more computer readable storage media 270 ( Figure 2 Only one is shown in FIG. 1 ). Computer-readable storage media 270 includes non-transitory media and may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. These instructions may be executed by processor 230 to perform various functions described herein.

[0072] exist Figure 2In the example of , computing device 200 can be a communication device, a storage device, or any device capable of running software components. For non-limiting examples, computing device 200 can be, but is not limited to, a local smart wheel server, a local user device, a remote server, a remote user device, a device platform, a remote satellite, a smart phone, a laptop PC, a desktop PC, a tablet computer, a Google TM Android TM equipment, and a voice-controlled speaker or controller.

[0073] The computing device 200 has a communication interface 280 that enables the computing device 200 to communicate with users and other devices using one or more known communication media and communication protocols. Here, the communication media and protocols may be, but are not limited to, the Internet, an intranet, a wide area network (WAN), a local area network (LAN), a wireless network, Bluetooth, WiFi, and a mobile communication network.

[0074] In some embodiments, the communication interface 280 may include any suitable hardware, software, or combination of hardware and software capable of coupling the computing device 200 to one or more networks and / or additional devices. The communication interface 280 may be arranged to operate using any suitable technology for controlling information signals using a set of desired communication protocols, services, or operating procedures. The communication interface 280 may include an appropriate physical connector for connecting to a corresponding communication medium (whether wired or wireless). In some embodiments, the communication interface 280 includes a radio frequency (RF) communication circuit and at least one antenna for sending and receiving RF signals according to various known communication protocols (e.g., LTE, 5G, Wifi, etc.).

[0075] A communication network can be used as a means of communication. In various aspects, a network can include a local area network (LAN) and a wide area network (WAN), including but not limited to the Internet, a wired channel, a wireless channel, a communication device including a telephone, a computer, a wired, a radio, an optical or other electromagnetic channel, and combinations thereof, including other devices and / or components capable of transmitting / associated with transmitting data. For example, a communication environment includes in-vivo communication, various devices, and various communication modes, such as wireless communication, wired communication, and combinations thereof.

[0076] Wireless communication modes include any communication mode between points (e.g., communication nodes) that utilize, at least in part, wireless technologies including various protocols and combinations of protocols associated with wireless transmission, data, and devices. Communication nodes may include, for example, wireless devices such as mobile terminals, fixed terminals, base stations, access points, smart phones, and other known devices capable of wireless communication via various wireless communication protocols. Other examples of communication nodes may include wireless headsets, audio and multimedia devices and equipment (such as audio players and multimedia players), phones (including mobile phones and cordless phones), and computers and computer-related devices and components (such as printers, network-connected machines, and / or any other suitable devices or third-party devices).

[0077] Wired communication mode includes any communication mode between the points of wired technology that utilizes various protocols associated with wired transmission, data and equipment and the combination of protocols.These points, for example, include devices such as audio and multimedia devices and equipment (such as audio players and multimedia players), phones (including mobile phones and cordless phones), and computers and computer-related devices and components (such as printers, network-connected machines and / or any other suitable equipment or third-party devices).In various implementations, the wired communication module can communicate according to a variety of wired protocols.The example of wired protocol can include universal serial bus (USB) communication, RS-232, RS-422, RS-423, RS-485 serial protocol, FireWire, Ethernet, Fiber Channel, MIDI, ATA, Serial ATA, PCI Express, T-1 (and variants), Industry Standard Architecture (ISA) parallel communication, small computer system interface (SCSI) communication or peripheral component interconnect (PCI) communication, just to name a few examples.

[0078] Thus, in various aspects, the communication interface 280 may include, for example, one or more interfaces, such as a wireless communication interface, a wired communication interface, a network interface, a transmission interface, a reception interface, a media interface, a system interface, a component interface, a switch interface, a chip interface, a controller, etc. For example, when implemented by a wireless device or within a wireless system, the communication interface 280 may include a wireless interface that includes (e.g., includes) one or more antennas, transmitters, receivers, transceivers, amplifiers, filters, control logic, etc.

[0079] In various aspects, the communication interface 280 can provide data communication functions according to a variety of protocols. Examples of protocols may include various wireless local area network (WLAN) protocols, including the Institute of Electrical and Electronics Engineers (IEEE) 802.xx series of protocols, such as IEEE 802.11a / b / g / n, IEEE 802.16, IEEE 802.20, etc. Other examples of wireless protocols may include various wireless wide area network (WWAN) protocols, such as GSM cellular radiotelephone system protocols with GPRS, CDMA cellular radiotelephone communication systems with 1xRTT, EDGE systems, EV-DO systems, EV-DV systems, HSDPA systems, 4G-LTE, 5G (new radio), etc. Further examples of wireless protocols may include wireless personal area network (PAN) protocols, such as infrared protocols, protocols from the Bluetooth Special Interest Group (SIG) protocol family, including Bluetooth specification versions v1.0, v1.1, v1.2, v2.0, v2.0 with enhanced data rate (EDR), and one or more Bluetooth profiles, etc. Another example of a wireless protocol may include near field communication techniques and protocols, such as electromagnetic induction (EMI) techniques. Examples of EMI techniques may include passive or active radio frequency identification (RFID) protocols and devices. Other suitable protocols may include ultra-wideband (UWB), digital office (DO), digital home, trusted platform module (TPM), ZigBee, etc.

[0080] Figure 3A300 according to various embodiments. The smart wheel 300 may include a device platform 302 of at least one device. More specifically, the device platform 302 may include at least one device as a sensor within a sensor housing 304 and at least one device as an energy collector 306. The device platform may be supported by (e.g., positioned along) a rotatable component 308 of the smart wheel 300. The rotatable component 308 may, for example, include a rim of the smart wheel 300, within which the circumference of the rotatable component 308 is confined. Although the device platform is shown as eight pairs of sensor housings 304 and energy collectors 306, in various embodiments, any number of sensor housings and energy collectors may be implemented in the device platform as needed for different applications. For example, other embodiments may include multiple sensor housings for each energy collector, and yet other embodiments may include multiple energy collectors for each sensor housing. Although some embodiments describe the sensor housing 304 as being located directly on the rim 308A of the smart wheel 300 (e.g., on the rim of the rotatable component 308 of the smart wheel 300), in various embodiments, the sensor housing may be located in other portions of the smart wheel 300 as desired for different applications. For example, the sensor housing (and the sensor included therein) may be located closer to the center of the rotatable component 308, such as along the spokes 308B of the rotatable component 308 or around the center 308C of the rotatable component 308 (e.g., adjacent to the hub cap) in certain embodiments.

[0081] In various embodiments, the sensor housing may represent one or more sensors together within the sensor housing and functional modules such as, for example, a battery or other energy storage medium configured to store energy generated by the energy harvester. In some embodiments, the sensor housing may include a system bus (e.g., conductive elements of a printed circuit board) that connects the various parts of the sensor housing together.

[0082] In addition, the sensor housing may include other functional modules, such as a communication interface for transmitting sensor data captured by various sensors of the sensor housing to a local smart wheel server. The communication interface may, for example, include a communication interface for data unloading (e.g., via millimeter and / or gigahertz wavelength communication) to a local smart wheel server, other vehicles, infrastructure (e.g., remote network) and / or user equipment. As a further example, the communication interface may facilitate wireless communication, such as via Bluetooth, radio frequency, radio waves, ultrasound and / or any other type of communication protocol or medium. The communication interface may be configured to communicate, for example, with an on-board electronic control unit (ECU) and / or an advanced driver assistance (ADAS) system on a vehicle. In addition, the sensor housing may optionally include a processor or any other circuit to facilitate the collection, communication and / or analysis of sensor data generated by the constituent sensors of the sensor housing.

[0083] According to various embodiments, various types of sensors may be integrated with the sensor housing. For example, the sensor housing may include a shock sensor that can sense the amount of potential generated by the energy harvester. The shock sensor may be configured to wake up or otherwise activate the sensor and / or functional module of the sensor housing when the energy harvester generates a sufficient amount of potential. In other words, the shock sensor may conceptually include an energy harvester so that the shock sensor is configured to generate energy exceeding a threshold amount in response to mechanical deformation based on the energy harvester, and the various sensors and / or functional modules of the sensor housing are transformed from a low-power or inactive state to a powered or active state. In some embodiments, when the energy harvester does not generate any energy (e.g., when there is no mechanical stress applied to the energy harvester), the energy sensed by the shock sensor can be stored in a battery for backup power.

[0084] In a particular embodiment, the sensor housing may include an altitude sensor configured to generate air pressure sensor data. Thus, the altitude sensor may be an air pressure sensor or an atmospheric pressure sensor that can measure atmospheric pressure, which may indicate altitude or height. The air pressure sensor data may be used, for example, to determine the height of the smart wheel from a reference point such as a road and / or relative to other smart wheels of the vehicle. This may allow the determination of a rollover risk or a flat tire. As described above, the altitude sensor on the smart wheel may be located on a rotatable component of the wheel and therefore not on the chassis of the vehicle. Therefore, such an altitude sensor is capable of providing air pressure sensor data about which side (e.g., which smart wheel) caused the rollover (e.g., when such air pressure sensor data is generated and recorded in a continuous or semi-continuous manner). In addition, the air pressure sensor data generated by the smart wheel may more accurately sense road conditions such as potholes compared to sensor data generated from a static portion of the chassis of the vehicle. In some embodiments, the altitude sensor is configured to also measure the deflection of the inner surface of the tire due to vehicle load or contact area. In some embodiments, a distance measurement sensor may be placed in a pressurized portion of the tire. When the tire rotates, the distance of the tire relative to the central rotating rim changes. This periodic variation in distance is detectable.

[0085] In other embodiments, the sensor housing may include an acoustic sensor configured to generate acoustic sensor data. Thus, the acoustic sensor may be any type of acoustic, sound or vibration sensor, such as a seismometer, a microphone, a seismometer, and a sound locator. The acoustic sensor data may be used for audio pattern recognition, such as an audio signature for sensing a brake or rotor of a rotatable component (e.g., a wheel). This may be used to predict a vehicle maintenance schedule and / or generate performance optimization data. In some embodiments, for example, the acoustic sensor data may be analyzed to identify and / or monitor unique signatures of different fracture and wear conditions.

[0086] In various embodiments, the sensor housing may include an image sensor configured to generate image sensor data from variable attenuation of waves. Examples of image sensors may include active pixel sensors in semiconductor charge coupled devices (CCDs) or complementary metal oxide semiconductors (CMOS) or N-type metal oxide semiconductor (NMOS) technologies. In various embodiments, the device platform including the image sensor may include a lens or other transparent medium based on which light waves are focused from the outside of the sensor housing onto the image sensor. In a specific embodiment, the image sensor may include a time of flight (TOF) sensor to capture time of flight data that can characterize TOF. The TOF sensor may, for example, be an ultrasonic TOF sensor configured to collect ultrasonic TOF sensor data. As a more specific example, the image sensor may function as a camera for determining visibility of tire tread depth to evaluate tire performance and optimization. Such image sensors that capture image data characterizing tire tread depth may also be positioned in a manner that enables image data of the tire tread to be captured (e.g., by enabling such image sensors to capture image data characterizing the tread depth of a smart tire on which the image sensor is located or a tire on which the image sensor is not located). According to various embodiments, the position of the image sensor may be inside or outside the rim so that the sensor can image the sidewall of the tire. In either case, the image sensor can be electrically coupled to the energy harvester. As another specific example, the image sensor can include an infrared image sensor for authentication or identification. The infrared sensor can, for example, be used to scan the local environment or the characteristics of a local object (e.g., a person approaching a vehicle) for authentication.

[0087] In certain embodiments, the sensor housing may include a gas sensor configured to generate gas sensor data. The gas sensor may be any type of sensor for monitoring and characterizing a gas atmosphere. For example, the gas sensor may utilize any of a variety of mechanisms for gas detection, such as an electrochemical gas sensor, a catalytic bead gas sensor, a photoionization gas sensor, an infrared point gas sensor, a thermal imaging gas sensor, a semiconductor gas sensor, an ultrasonic gas sensor, a holographic gas sensor, and the like. These gas sensors may, for example, detect certain types of gases, such as exhaust gases, explosive gases (e.g., for battery fault detection), atmospheric humidity, air quality, particles, pH, and the like.

[0088] In certain embodiments, the sensor housing may include a magnetic sensor configured to generate magnetic sensor data. For example, the magnetic sensor may be a magnetometer that measures magnetism for navigation using a magnetic field map (e.g., within a building or within a closed environment).

[0089] In additional embodiments, the sensor housing may include an accelerometer sensor configured to generate acceleration sensor data and / or a gyroscope sensor configured to generate gyroscope sensor data. The acceleration sensor data and / or gyroscope sensor data may be used for navigation, such as determining an amount of acceleration for application of an emergency braking system. In some embodiments, the accelerometer sensor and / or gyroscope sensor may be part of an inertial navigation system (INS) located on the smart wheel.

[0090] The energy harvester 306 may be positioned along the rotatable component 308 (e.g., rim) of the smart wheel 300 in a manner configured to capture kinetic energy in response to compressive forces acting on a flexible component 310 (e.g., pneumatic or inflatable tire, inner tube, etc.) of the smart wheel 300 that contacts a road or object when the rotatable component 308 rotates. In some embodiments, the energy harvester 306 and / or the device platform 302 may be visible from a lateral side of the vehicle or smart wheel 300 (e.g., adjacent to a lateral sidewall of the vehicle or smart wheel 300). However, in other embodiments, the energy harvester 306 and / or the device platform 302 may not be visible from a lateral side of the vehicle or smart wheel 300. The energy harvested by the energy harvester 306 may be used to power various components of the device platform 302, such as various sensors and / or communication interfaces within the sensor housing 304, as described in further detail below.

[0091] In various embodiments, the energy collector 306 can be located on a sidewall of the rotatable component 308. For example, the energy collector 306 can be located between the rotatable component 308 (e.g., a rim, an axle, etc.) and the bead region of the flexible component 310 (e.g., a tire, an inner tube, an annulus, etc.). Thus, the flexible component 310 can be mounted on the rotatable component 308. When the vehicle travels on a surface (e.g., a road), the energy collector 306 can generate energy caused by the compressive force acting on the bead region of the flexible component 310 (e.g., a tire, an inner tube, etc.).

[0092] Figure 3B308. As shown, the energy harvester 306 can be positioned around the circumference of the rotatable component 308. Thus, the energy harvester 306 can generate energy caused by the compressive force of a moving object (e.g., a vehicle, acting on the bead area of ​​a tire mounted on the rotatable component 308). In some embodiments, the compressive force can be attributed to loading (e.g., acceleration, deceleration, etc.). Therefore, the location of the compressive force can vary depending on the loading. In other embodiments, the energy harvester 306 can capture the kinetic energy of a vehicle moving in response to the rotation of the rotatable component 308. Thus, when mechanical stress is applied to the energy harvester 306, the energy harvester 306 can generate energy.

[0093] Figure 4A 400A is a perspective view of an energy harvester 306 according to various embodiments. The energy harvester 306 can be positioned along the circumference of a rotatable component 308 (e.g., a wheel rim). The energy harvester 306 can include a substrate 402 configured to contact the rotatable component 308 and fixedly coupled to the rotatable component 308. The substrate 402 can support a piezoelectric component 404. According to some embodiments, the piezoelectric component can be a transducer that converts mechanical deformation into energy.

[0094] The energy harvester 306 may include an electrically conductive component 406 configured to channel and unload energy generated by the piezoelectric component 404. The electrically conductive component can be connected to other devices of the device platform (e.g., sensors of the sensor housing) to provide power to the other devices of the device platform. In some embodiments, the electrically conductive component 404 can be composed of a flexible conductive material such as brass or copper. The energy harvester 306 may also include a locating pin 408, based on which the piezoelectric component 404 can be fixed to the substrate 402. For example, the piezoelectric component 404 may include a wingtip feature 409 having an opening, and the locating pin 408 is configured to pass through the opening in a secure manner to fix the piezoelectric component to the substrate 402, as described in further detail below.

[0095] In various embodiments, the substrate 402 may include a three-dimensional curved bottom surface 410 that is interfaced with the rotatable component 308 (e.g., a rim) of the smart wheel. The three-dimensional curved bottom surface 410 may include a composite curve in three dimensions (e.g., length, height, and width). As described above, each of the length, height, and width may define a dimension or axis that is orthogonal to each other in a three-dimensional physical space. For example, the length may be along an axis orthogonal to the height, the height may be along an axis orthogonal to the width, and the width may be along an axis orthogonal to the length. In some embodiments, the length, height, and width may be referred to as the x-axis, z-axis, and y-axis, respectively. In addition, the substrate 402 may include a curved segmented surface 412 (e.g., a microcavity or depression) opposite to the bottom surface 410. The segmented surface 412 (e.g., a top surface) may also be referred to as the top surface of the substrate. In some embodiments, the curved segmented surface 412 is curved in only two dimensions (e.g., two of the length, height, and width, as described in further detail below). When a force is applied to the piezoelectric component 404, the piezoelectric component 404 will deform and conform to the two-dimensional curved segmented surface 412, which limits the amount of deformation of the piezoelectric component 404. Thus, the piezoelectric component 404 can be seated on the rotatable component 308 via the three-dimensional curved bottom surface 410. In addition, the rectangular piezoelectric component 404 can be configured to bend within the two-dimensional curved segmented surface 412. In some embodiments, the two-dimensional curved segmented surface 412 can be referred to as a convex surface. Thus, the two-dimensional curved segmented surface 412 can include (e.g., be) a convex surface, and the piezoelectric component 404 having a straight (e.g., non-curved or flat) shape or surface can be attached to the convex surface. In some embodiments, the substrate 402 can be referred to as a teardrop support. Thus, the piezoelectric component 404 can bend against the convex two-dimensional curved segmented surface 412 to generate a compressive bending strain on the piezoelectric component 404. In other words, the piezoelectric assembly 404 can induce strain such that the piezoelectric assembly 404 is bent to conform to the convex two-dimensional curved segmented surface 412 (e.g., against the convex curvature) to generate an electric charge (e.g., via mechanical deformation of the piezoelectric material layer). Thus, the substrate 402 can be configured such that strain (e.g., relative movement / deflection) of the piezoelectric assembly 404 is possible when placed between the rotatable assembly 308 of the wheel and the tire (e.g., by the tire pushing down on the piezoelectric assembly 404).

[0096] In various embodiments, the piezoelectric component 404 may include a piezoelectric material that is at least one of a crystalline and semiconductor material or a polymer and an organic material. Examples of crystalline and semiconductor materials may include: polyvinylidene fluoride, gallium phosphate, sodium bismuth titanate, lead zirconate titanate, quartz, apatite (AlPO4), sucrose (sugar), Rochelle salt, topaz, tourmaline family minerals, lead titanate (PbTiO3), lanthanum gallium silicate (La3Ga5SiO14), gallium orthophosphate (GaPO4), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), any ceramic family with perovskite, tungsten bronze, potassium niobate ( KNbO3), sodium tungstate (Na2WO3), Ba2NaNb5O5, Pb2KNb5O15, potassium sodium niobate ((K,Na)NbO3) (e.g., NKN or KNN), bismuth ferrite (BiFeO3), sodium niobate (NaNbO3), barium titanate (BaTiO3), bismuth titanate (Bi4Ti3O12), sodium bismuth titanate (NaBi(TiO3)2), sphalerite crystals, GaN, InN, AlN, and ZnO. Examples of polymers and organic materials may include polyvinylidene fluoride (PVDF) and its copolymers, polyamide and paralyne-C, polyimide and polyvinylidene chloride (PVDC), and diphenylalanine peptide nanotubes (PNTs).

[0097] In various embodiments, the substrate 402 may include at least one material such as: brass, steel, spring steel (SS), carbon fiber, aluminum and its alloys, titanium and its alloys, S2 fiberglass rods, glass fiber reinforced polymer laminates (Fiberite HMS / 33), fiberglass, Kevlar laminates, carbon fiber reinforcements, aramid fiber reinforcements, fiber reinforced plastics (FRP), copper and alloys.

[0098] Figure 4B 4 is a top view 400B of energy harvester 306 according to various embodiments. Top view 400B illustrates how electrically conductive component 406 may be connected to piezoelectric component 404 via interconnect 416. In other words, interconnect 416 may be a flexible structure that connects piezoelectric component 404 to electrically conductive component 406 so that electrically conductive component 406 may direct and unload energy generated by piezoelectric component 404. The electrically conductive component may be connected to other devices of the device platform to provide power to the other devices of the device platform.

[0099] In addition, top view 400B illustrates how substrate 402 may also include locating pins 408 to secure piezoelectric assembly 404 to substrate 402. For example, piezoelectric assembly 404 may include a wingtip feature 409 having an opening through which locating pins 408 are configured to pass to secure the piezoelectric assembly to substrate 402. A two-dimensional curved segmented surface 412 within a cavity formed by substrate 402 is also illustrated. Figure 4B It also illustrates the following combination Figure 5A and Figure 5B Further reference is made to section line AA.

[0100] Figure 4C 400C is a front view of the energy harvester 306 according to various embodiments. The front view 400C illustrates how the electrically conductive component 406 may generally be located behind the substrate 402. In addition, the front view 400C illustrates how the substrate 402 may also include another view of the locating pins 408 for securing the piezoelectric component 404 to the substrate 402. For example, the piezoelectric component 404 may include a wingtip feature 409 having an opening through which the locating pins 408 are configured to pass to secure the piezoelectric component to the substrate 402. A two-dimensional curved segmented surface 412 within the cavity formed by the substrate 402 is also illustrated.

[0101] Figure 4D 4 is a rear view 400D of an energy harvester 306 according to various embodiments. The rear view 400D illustrates how the electrically conductive component 406 may generally be located behind the substrate 402 (e.g., in the foreground in the rear view 400D). The rear view 400D also includes a three-dimensional curved bottom surface 410 and a physical interconnection feature 420 on the substrate 402. The physical interconnection feature 420 may be used to physically connect different substrates 402 together, as discussed in further detail below. The physical interconnection feature 420 shown may be a physical interconnection feature ( Figure 4D 4. A raised physical interconnect feature 420 for interconnecting (not shown) the substrate.

[0102] Figure 4E 4 is a bottom view 400E of an energy harvester 306 according to various embodiments. Bottom view 400E illustrates how an electrically conductive component 406 may generally be located behind a substrate 402. Bottom view 400E also includes a three-dimensional curved bottom surface 410 and a physical interconnection feature 420 on the substrate 402. As described above, the physical interconnection feature 420 may be used to physically connect different substrates 402 together, as discussed in further detail below. The physical interconnection feature 420 shown may be a physical interconnection feature ( Figure 4E 4. The physical interconnect features 420 of the convex surface of the interconnect (not shown) are shown.

[0103] Figure 4F is a right side view 400F of the energy harvester 306 according to various embodiments. In addition, Figure 4G Illustrated is a left side view 400G of the energy harvester 306 according to various embodiments. Figure 4F and Figure 4GThe combination of the two can be referred to as a side view. The side view illustrates an electrically conductive component 406 that can be connected to the piezoelectric component 404 via an interconnect 416. In other words, the interconnect 416 can be a flexible structure that connects the piezoelectric component 404 to the electrically conductive component 406 so that the electrically conductive component 406 can guide and unload the energy generated by the piezoelectric component 404. The electrically conductive component can be connected to other devices of the device platform to provide power to the other devices of the device platform. The side view also illustrates a three-dimensional curved bottom surface 410.

[0104] Figure 5A 5 is a side cross-sectional view 500A of the energy harvester 306 with the piezoelectric assembly 404 in an unbiased state according to various embodiments. The side cross-sectional view 500A may be viewed across the top of the energy harvester 306. Figure 4B Section AA shown in. Return to Figure 5A , side cross-sectional view 500A illustrates how electrically conductive component 406 may be connected to piezoelectric component 404 via interconnect 416. Thus, interconnect 416 may be a flexible structure that connects piezoelectric component 404 to electrically conductive component 406 so that electrically conductive component 406 may direct and unload energy generated by piezoelectric component 404. The electrically conductive component may be connected to other devices of the device platform to provide power to the other devices of the device platform.

[0105] In addition, the side cross-sectional view 500A illustrates how the substrate 402 may also include a locating pin 408 based on which the piezoelectric assembly 404 may be fixed to the substrate 402. In addition, a two-dimensional curved segmented surface 412 within the cavity formed by the substrate 402 is also illustrated. The three-dimensional curved bottom surface 410 is shown below and opposite the two-dimensional curved segmented surface 412. Figure 5A As shown in , the two-dimensional curved segmented surface 412 is curved in two dimensions (e.g., width and height dimensions, but not length dimension) to form a 2-D convex surface. In contrast, the three-dimensional bottom surface 410 is curved in each of the width, height, and length dimensions. In some embodiments, the 3-D bottom surface 410 has an S-shaped cross-section, such as Figure 5A The piezoelectric assembly 404 in the unbiased state may be flat (eg, unbent) in the unbiased state because it may not experience sufficient strain to be biased.

[0106] Figure 5B 500B is a side cross-sectional view of the energy harvester 306 with the piezoelectric assembly 404 in a biased state according to various embodiments. The side cross-sectional view 500B may be viewed across the top of the energy harvester 306. Figure 4B Section AA shown in. Return to Figure 5B, the piezoelectric assembly 404 in a biased state can experience an amount of strain sufficient to bend the piezoelectric assembly so that it conforms to the two-dimensional curved segmented surface 412. As described above, when the rotatable assembly rotates, the piezoelectric assembly 404 can alternate between a biased state and an unbiased state. Therefore, the load from the wheel or vehicle can displace the piezoelectric assembly and generate an electric charge (e.g., electrical energy). In some embodiments, when the rotatable assembly rotates, the energy collector can generate continuous electricity. In certain embodiments, the energy can be in the form of an alternating current (AC) signal, which can be rectified into a direct current (DC) signal. In other words, the bending strain experienced at the piezoelectric assembly can generate energy (e.g., an alternating current (AC) voltage) whose frequency is proportional to the rotation frequency of the wheel. In some embodiments, the AC signal is rectified by a rectifier circuit contained in the sensor 304.

[0107] Figure 6600 is a perspective view of an integrated energy harvester 606 according to various embodiments. The integrated energy harvester 606 can be positioned along the circumference of a rotatable component 608 (e.g., a rim) without requiring a substrate. In other words, the integrated energy harvester 606 can be integrated within the rotatable component 608, so there is no separate physical substrate structure. The rotatable component 608 can include a curved segmented surface 612 formed on the rotatable component 608 (e.g., a microcavity or depression formed on the rotatable component 608). In some embodiments, the curved segmented surface 12 is curved only in two dimensions (e.g., height and width directions, but not length direction) to form a two-dimensional convex surface 612. The piezoelectric component 614 can generate strain to deform and conform to the two-dimensional curved segmented surface 612. In addition, the two-dimensional curved segmented surface 612 can be different from the rest of the rotatable component 608, which can have a three-dimensional curved surface. The rectangular piezoelectric component 614 can be configured to bend within the two-dimensional curved segmented surface 612. In some embodiments, the two-dimensional curved segmented surface 612 can be referred to as a convex surface. Thus, the two-dimensional curved segmented surface 612 can include (e.g., be) a convex surface, to which a piezoelectric component 604 having a straight (e.g., non-curved or flat) shape or surface can be more easily and securely attached than a 3-D curved surface. The piezoelectric component 604 can bend against the convex two-dimensional curved segmented surface 612 to produce a compressive bending strain on the piezoelectric component 614. In other words, the piezoelectric component 614 can induce a strain such that the piezoelectric component is bent to conform to the convex two-dimensional curved segmented surface 612 (e.g., bend against the convex surface) to generate an electric charge (e.g., via mechanical deformation of the piezoelectric material layer). Thus, the convex two-dimensional curved segmented surface 612 of the rotatable component 608 can be configured such that strain (e.g., relative movement / deflection) of the piezoelectric component 614 is possible when placed between the rotatable component 608 and the tire of a wheel (e.g., by the tire pushing downward on the piezoelectric component 614).

[0108] The integrated energy harvester 606 may include an electrically conductive component 616 configured to direct and unload the energy generated by the piezoelectric component 614. The electrically conductive component may be connected to the sensor housing 304 ( Figure 3A and Figure 3B ) to provide power to the sensor within the sensor housing 304. In some embodiments, the electrically conductive component 616 can be composed of a flexible conductive material such as brass or copper. The integrated energy harvester 606 can also include locating pins (not shown) to secure the piezoelectric component 614 to the convex two-dimensional curved segmented surface 612 of the rotatable component 608.

[0109] In some embodiments, the piezoelectric assembly 614 can be formed of different types of layers. For example, one type of layer of the piezoelectric assembly 614 can be a load-bearing backing layer. The load-bearing backing layer can be, for example, a steel plate with sufficient load flexibility to hold the piezoelectric assembly together. Another type of layer of the piezoelectric assembly can be a piezoelectric material layer that can be configured to generate an electric charge via mechanical deformation. Yet another type of layer of the piezoelectric assembly can be an electrode layer that collects electrical energy (e.g., an electric charge) from the piezoelectric material layer.

[0110] In some embodiments, when bonded to the piezoelectric ceramic material of the piezoelectric material layer, the load backing layer ensures that the piezoelectric ceramic material does not crack or buckle under the "compressive and / or tensile stresses" imposed on the piezoelectric ceramic material during bending. In various embodiments, the electrode layer can be electrically bonded to other layers of the piezoelectric assembly (e.g., bonded to the load backing layer and / or the piezoelectric material layer). In addition, the load backing layer can be electrically and / or mechanically bonded to the piezoelectric material layer. The assembly of all layers of the piezoelectric assembly can form a piezoelectric assembly (which can be referred to as a piezoelectric electrode assembly in some embodiments). In other embodiments, the piezoelectric assembly can be encapsulated in a protective coating, such as a heat shrink film or a polymer, to protect the piezoelectric assembly from environmental degradation.

[0111] Fig. 7A An example of a piezoelectric assembly 730 according to an embodiment of the present disclosure is illustrated. In this example, the piezoelectric assembly 730 includes an electrode layer 732, a piezoelectric material layer 734, a conductive bonding layer 736, and a load-bearing backing layer 738. Additional layers may also be implemented, but are not shown for ease of illustration.

[0112] The conductive bonding layer 736 can be referred to as a bonding layer for bonding the piezoelectric material layer 734 and the load backing layer 738. In one example, the conductive bonding layer 736 includes metal powder and resin. In another example, the conductive bonding layer 736 is vertically above the load backing layer 738 and in direct contact with the load backing layer 738, and the piezoelectric material layer 734 is vertically above the conductive bonding layer 736, and the piezoelectric material layer 734 is horizontally surrounded by the electrode layer 732. In one example, the load backing layer 738 includes a fiber reinforced composite material with a high elastic modulus, and the conductive bonding layer 736 is used to transfer the effect of the high elastic modulus from the fiber reinforced composite material to the piezoelectric material layer 734. In this way, when the piezoelectric assembly 730 is deformed under mechanical strain, the piezoelectric assembly 730 can quickly and more frequently (i.e., more cycles than when steel is used for the load backing layer 738) "bounce" to its original shape. Therefore, electricity can be generated more efficiently and for more cycles in the energy harvester 306.

[0113] In some embodiments, the load backing layer 738 includes a fiber reinforced composite material and a surface layer. In one example, the surface layer is a resin layer. In another example, when the conductive bonding layer 736 is located vertically above the load backing layer 738 and in direct contact with the load backing layer 738, the surface layer is located between the fiber reinforced composite material and the conductive bonding layer 736. In some embodiments, the surface layer is removed from the load backing layer 738 so that the fiber reinforced composite material in the load backing layer 738 is exposed and in direct contact with the conductive bonding layer 736. In this way, after removing the surface layer, the elastic modulus in the fiber reinforced composite material may be higher than the elastic modulus in the fiber reinforced composite material before removing the surface layer. In yet another example, the surface layer is removed using a mechanical etching process or a laser etching process.

[0114] Figure 7B The diagram illustrates a top view of a CFC material 742 with a covered surface layer and a CFC material 744 with the surface layer removed. In some embodiments, the covered surface layer of the CFC material 742 is a resin layer. Removing the covered surface layer of the CFC material 742 can increase the elastic modulus. Therefore, the CFC material 744 with the surface layer removed can experience a higher elastic modulus. In this way, when the CFC material 744 is directly connected to the conductive bonding layer that is directly connected to the piezoelectric layer, the piezoelectric layer can quickly recover to its original shape after being deformed under mechanical strain. In addition, removing the surface (resin) layer of the CFC material 744 can provide better adhesion and bonding between the load-bearing backing layer 738 and the conductive bonding layer 736.

[0115] Fig. 8A Yet another example of a piezoelectric assembly 800 according to an embodiment of the present disclosure is illustrated. In this example, the piezoelectric assembly 800 includes two electrode layers 802 and 808, a piezoelectric material layer 806, two conductive bonding layers 804 and 810, a load backing layer 812, and wires 814 connected to the electrode layer 808. Additional layers may also be implemented, but are not shown for ease of illustration. The functions of the piezoelectric material layer 806, the electrode layer 808, the conductive bonding layer 810, and the load backing layer 812 are described above with reference to Figure 7B Additional layers included in this embodiment are electrode layer 802, conductive bonding layer 804, and wire 814, and are described in detail herein.

[0116] The electrode layer 802 may be used to indirectly contact (e.g., via the conductive bonding layer 804) the piezoelectric material layer 806 to collect charge from the piezoelectric material layer 806. In some embodiments, the electrode layers 802 and 808 may represent different circuits with different potentials such that there is a potential difference between the electrode layers 802 and 808. The potential difference between the electrode layers 802 and 808 may then be used to provide power to the devices of the smart wheel sensor system through the wires 814.

[0117] The conductive bonding layer 804 can be used to bond the piezoelectric material layer 806 and the electrode layer 802. In some embodiments, the conductive bonding layer 804 includes metal powder and resin, and is located vertically above the piezoelectric material layer 806 and directly contacts the piezoelectric material layer 806.

[0118] Figure 8B The diagram illustrates a cross-sectional view of a piezoelectric assembly 800 according to an embodiment of the present disclosure. The functions of the electrode layers 802 and 808, the piezoelectric material layer 806, the conductive bonding layers 804 and 810, and the load-bearing backing layer 812 are described above with reference to Fig. 8A In some embodiments, the piezoelectric material layer 806 is surrounded by the electrode layer 808 with a gap 814 between the inner peripheral edge of the electrode layer 808 and the outer peripheral edge of the piezoelectric material layer 806 to prevent short circuits between the layers 806 and 808. In some embodiments, the gap 814 is 100 μm or greater.

[0119] Fig.9A Another example of a piezoelectric assembly 900 according to an embodiment of the present disclosure is illustrated. In this example, the piezoelectric assembly 900 includes an electrode layer 902, a piezoelectric material layer 904, a metal layer 906, a conductive bonding layer 908, and a load backing layer 910. Additional layers may also be implemented, but are not shown for ease of illustration. The functions of the electrode layer 902, the piezoelectric material layer 904, the conductive bonding layer 908, and the load backing layer 910 are described above with reference to Figure 7B An additional layer included in this embodiment is the metal layer 906 and is described in detail herein.

[0120] The metal layer 906 may be referred to as a layer made of a metal for improving conductivity between the piezoelectric material layer 904 and the conductive bonding layer 908. Examples of the metal layer 906 include a silver (Ag) metal layer, a copper (Cu) metal layer, an aluminum (Al) metal layer, a gold (Au) metal layer, and / or any other type of metal layer.

[0121] In one example, the metal layer 906 has a thickness in the range of 1.0 to 20 μm. In another example, the metal layer 906 has a thickness in the range of 3.0 to 10 μm. In yet another example, the piezoelectric material layer 904 has a thickness in the range of 30 to 500 μm. In yet another example, the piezoelectric material layer 904 has a thickness in the range of 50 to 200 μm. In yet another example, the conductive bonding layer 908 has a thickness in the range of 1.0 to 100 μm. In yet another example, the conductive bonding layer 908 has a thickness in the range of 5.0 to 50 μm. In some embodiments, the conductive bonding layer 908 includes metal powder and resin. Examples of metal powders in the conductive bonding layer 908 include Ag metal powder, Cu metal powder, Al metal powder, Au metal powder and / or any other type of metal powder.

[0122] In some embodiments, the conductive bonding layer 908 is vertically above and in direct contact with the load backing layer 910, the metal layer 906 is vertically above and in direct contact with the conductive bonding layer 908, the piezoelectric material layer 904 and the electrode layer 902 are vertically above and in direct contact with the metal layer 906, and the piezoelectric material layer 904 is horizontally surrounded by the electrode layer 902 and in direct contact with the electrode layer 902.

[0123] Fig. 9B The diagram illustrates a microscopic cross-sectional view of a piezoelectric material layer 904, a metal layer 906, a conductive bonding layer 908, and a load-bearing backing layer 910 in a piezoelectric assembly 900 according to an embodiment of the present disclosure. Fig. 9B As shown in , the piezoelectric material layer 904 includes voids 912a-n as shown. The voids 912a-n can be generated as a result of the sintering process, particularly during the cooling process after the sintering process. In some embodiments, the metal layer 906 and the piezoelectric material layer 904 are not sintered at the same time. In some examples, the sintering process is a liquid phase sintering that causes residual stress after the sintering process. Voids 912a-n can appear in order to relieve the residual stress after the sintering process. The residual stress in the material can be referred to as a physical quantity representing the internal force exerted by adjacent particles of the material on each other. Reducing the residual stress in the piezoelectric material layer 904 by the voids 912a-n makes the piezoelectric material layer 904 less fragile. Therefore, due to the presence of voids 912a-n, the piezoelectric material layer 904 may be less susceptible to fatigue cracking and delamination.

[0124] In some examples, the amount of voids in the piezoelectric material layer 904 is characterized by a porosity value. The porosity value in a material can be referred to as the percentage of void space in the material. In some embodiments, the porosity value is calculated as the ratio of the volume of voids in the material divided by the total volume of the material. In one example, the porosity value of the piezoelectric material layer 904 is in the range of 97% to 99.9%. In another example, the porosity value of the piezoelectric material layer 904 is in the range of 98% to 99.5%.

[0125] Fig. 10A Another example of a piezoelectric component 1000 according to an embodiment of the present disclosure is illustrated. In this example, the piezoelectric component 1000 includes an electrode layer 1002, a piezoelectric material layer 1004, an interface layer 1006, a metal layer 1008, a conductive bonding layer 1010, and a load backing layer 1012. The functions of the electrode layer 1002, the piezoelectric material layer 1004, the metal layer 1008, the conductive bonding layer 1010, and the load backing layer 1012 are described above with reference to Fig.9A An additional layer included in this embodiment is the interface layer 1006 and is described in detail herein.

[0126] Interface layer 1006 may be referred to as a layer formed between piezoelectric material layer 1004 and metal layer 1008 as a result of the sintering process that forms a bond between piezoelectric material layer 1004 and metal layer 1008. In some embodiments, interface layer 1006 is formed to further enhance the bond between piezoelectric material layer 1004 and metal layer 1008.

[0127] In some embodiments, the material of the interface layer 1006 is determined based on the material of the piezoelectric material layer 1004. In one example, the piezoelectric material layer 1004 includes a bismuth (Bi)-based piezoelectric material, and the resulting interface layer 1006 includes a Bi-based glass frit or a Bi-based slurry. In another example, the piezoelectric material layer 1004 includes a lead (Pb)-based piezoelectric material, and the resulting interface layer 1006 includes lead oxide. In some embodiments, the interface layer 1006 includes amorphous lead oxide or amorphous bismuth oxide. In some other embodiments, the interface layer 1006 includes a low melting point material, such as lead (IV) oxide (PbO2) with a melting point of 290°C.

[0128] Fig. 10BAn example of a cross-sectional scanning electron microscope (SEM) image of a piezoelectric material layer 1004, an interface layer 1006, a metal layer 1008, a conductive bonding layer 1010, and voids 1014a-n in a piezoelectric assembly 1000 according to an embodiment of the present disclosure is illustrated. The functions of the piezoelectric material layer 1004, the interface layer 1006, the metal layer 1008, the conductive bonding layer 1010, and the voids 1014a-n are described above with reference to Fig. 9B and Fig. 10A 1008. In some embodiments, the voids 1014a-n are formed as a result of the sintering process, particularly during the cooling process after the sintering process. In some examples, the voids 1014a-n are formed in the interface layer 1006 to reduce the internal stress of the interface between the piezoelectric material layer 1004, the interface layer 1006, and the metal layer 1008. In some examples, the sintering process is a liquid phase sintering that causes residual stress after the sintering process. The voids 1014a-n may appear so as to relieve the residual stress after the sintering process.

[0129] Fig.11A The diagram illustrates another example of a piezoelectric component 1100 according to an embodiment of the present disclosure. In this example, the piezoelectric component 1100 includes two electrode layers 1102 and 1108, two conductive bonding layers 1104 and 1114, two metal layers 1106 and 1112, a piezoelectric material layer 1110, and a load backing layer 1116. The functions of the electrode layers 1102 and 1108, the conductive bonding layers 1104 and 1114, the metal layer 1112, the piezoelectric material layer 1110, and the load backing layer 1116 are described above. Fig. 8A and Fig.9A The additional layer included in this embodiment is a metal layer 1106. The metal layer 1106 can be used to improve the conductivity between the piezoelectric material layer 1110 and the conductive bonding layer 1104.

[0130] Fig. 11B The diagram illustrates another example of a piezoelectric component 1120 according to an embodiment of the present disclosure. In this example, the piezoelectric component 1120 includes two electrode layers 1122 and 1130, two conductive bonding layers 1124 and 1138, two metal layers 1126 and 1136, two interface layers 1128 and 1134, a piezoelectric material layer 1132, and a load backing layer 1140. The functions of the electrode layers 1122 and 1130, the conductive bonding layers 1124 and 1138, the metal layers 1126 and 1136, the interface layer 1134, the piezoelectric material layer 1132, and the load backing layer 1140 are described above. Fig. 10A and Fig.11AThe additional layer included in this embodiment is an interface layer 1128. The interface layer 1128 may be formed to enhance the bonding between the piezoelectric material layer 1132 and the metal layer 1126. The material of the interface layer 1128 may be determined based on the material of the piezoelectric material layer 1132.

[0131] Fig. 11C Another example of a microscopic cross-sectional view of a piezoelectric assembly 1150 according to an embodiment of the present disclosure is illustrated. In some embodiments, the piezoelectric assembly 1150 includes a conductive bonding layer 1152, a metal layer 1154, a piezoelectric material layer 1156, a metal layer 1158, a conductive bonding layer 1160, a load backing layer 1162, and voids 1164a-n. The functions of the conductive bonding layer 1152, the metal layer 1154, the piezoelectric material layer 1156, the metal layer 1158, the conductive bonding layer 1160, the load backing layer 1162, and the voids 1164a-n are described above with reference to Fig. 9B and Fig. 10B has been described, so it will not be repeated here.

[0132] In some embodiments, the load backing layer 1140 may include a fiber reinforced composite material. Examples of fiber reinforced composite materials include carbon fiber composite (CFC) materials, glass fiber composite materials, carbon nanotube reinforced composite materials, graphene reinforced composite materials, and ceramic matrix composite materials. In some examples, the fiber reinforced composite material includes a CFC material. In one example, the CFC material includes a checkered interwoven structure. In another example, the CFC material includes a quasi-isotropic structure. The quasi-isotropic structure can be referred to as a structure made of a carbon fiber braid with plies oriented at various angles.

[0133] In some embodiments, the CFC structure results in a stiffer material (higher Young's modulus), which results in a higher strain for the same amount of stress, thereby imparting a higher strain to the piezoelectric material layer 1132 in the presence of the interface layer 1134. Thus, the energy harvester 306 can generate higher charge output and higher power using a lattice interlaced CFC structure or a quasi-isotropic CFC structure. For example, referring to Fig.12 , illustrating improved power generation using a carbon fiber composite material compared to a steel material. As can be seen, a CFC voltage generation timing diagram 1224 and a steel voltage generation timing diagram 1226 are illustrated, wherein the x-axis represents time in milliseconds and the y-axis represents the voltage value generated in the energy harvester 306. In some examples, the load backing layer 1140 using a steel material generates a peak-to-peak voltage value of 55 volts, while the load backing layer 1140 using a CFC material generates a peak-to-peak voltage value of 85 volts, which is approximately 50% higher than the peak-to-peak voltage value generated by the steel material.

[0134] In some embodiments, the specific microstructures in the lattice interwoven CFC structure and the quasi-isotropic CFC structure also provide higher elastic modulus, higher tensile strength, higher chemical resistance, higher temperature tolerance, lower thermal expansion and lower weight than the values ​​produced by the steel material embodiment of the load-bearing backing layer 1140. Examples of elastic modulus include Young's modulus, bulk modulus and transverse elastic modulus. In some embodiments, the quasi-isotropic CFC structure provides higher stiffness than the lattice interwoven CFC structure, thereby producing greater strain for the same amount of bending of the structure. In some embodiments, the laminated thermosetting epoxy resin can also be appropriately selected to further enhance the stiffness of the lattice interwoven CFC structure and the quasi-isotropic CFC structure, thereby making the lattice interwoven CFC structure and the quasi-isotropic CFC structure more robust to high temperatures.

[0135] In one example, the CFC material in the load-bearing backing layer 1140 includes from about 1500 kg / m 3 To about 2000kg / m 3 The piezoelectric components of the invention can be provided with a density in the range of about 1000 MPa to about 5000 MPa, a tensile strength in the range of about 3000 MPa to about 4000 MPa, and a Young's modulus in the range of about 300 GPa to about 500 GPa. The higher Young's modulus in the CFC material in the load backing layer 1140 can produce a higher mechanical strain imparted on the piezoelectric component to prevent cracking or degradation due to tensile and / or compressive forces acting on the piezoelectric component. Therefore, more deformation in the piezoelectric component can be produced throughout the service life of the integrated energy harvester.

[0136] Fig.13 1 is a flow chart of an energy harvester process 1800 according to various embodiments. The process 1800 may be performed at a smart wheel sensor system that integrates an energy harvester and at least one device configured to be powered by the energy harvester, as described above. It should be noted that the process 1800 is merely an example and is not intended to limit the present disclosure. Thus, it should be understood that the process 1800 may be performed at a smart wheel sensor system that integrates an energy harvester and at least one device configured to be powered by the energy harvester, as described above. Fig.13 Additional operations (eg, boxes) may be provided before, during, and after process 1800, some operations may be omitted, some operations may be performed concurrently with other operations, and some other operations may be described only briefly herein.

[0137] At box 1802, a wheel may move (e.g., rotate) under a load (e.g., the load of the wheel itself or an object driven by the wheel (e.g., a vehicle). As described above, the wheel may be a smart wheel or a smart wheel sensor system that integrates an energy harvester and at least one device configured to be powered by the energy harvester. The energy harvester includes a piezoelectric component placed on a curved segmented surface. The curved segmented surface may be a portion of a cavity into which the piezoelectric component may bend when a strain is induced (e.g., when biased). The curved segmented surface may be formed directly as a portion of the wheel, or may be formed on a substrate mounted on a portion of the wheel to facilitate applying strain to the piezoelectric component.

[0138] In addition, the energy harvester may include a piezoelectric component including a piezoelectric material layer and at least one electrode layer. In addition, the piezoelectric component may be connected to an interconnect and an electrically conductive component. The piezoelectric material layer may generate energy when mechanically deformed. The electrode layer may capture the energy generated by the piezoelectric material layer. The electrode layer may be connected to the electrically conductive component via an interconnect. The interconnect may be a flexible structure that connects the piezoelectric component to the electrically conductive component so that the electrically conductive component can guide and unload the energy generated by the piezoelectric component. The electrically conductive component may be connected to other devices of the device platform (e.g., sensors or energy storage media of the smart wheel sensor system) to provide power to other devices of the device platform.

[0139] At block 1804, a piezoelectric component of the energy harvester can be deformed (e.g., mechanically deformed) to generate energy resulting from a compressive force due to rotation of a wheel (e.g., of a vehicle, acting on a bead region of a tire mounted on a rotatable component). In other words, the piezoelectric component can capture kinetic energy of a vehicle moving in response to rotation of the rotatable component. Thus, when a mechanical stress is applied to the piezoelectric component, the piezoelectric component can generate energy. For example, the energy can be in the form of an alternating current (AC) signal that can be rectified into a direct current (DC) signal. In other words, the bending strain experienced at the piezoelectric component can generate energy (e.g., an AC voltage) at a frequency proportional to the frequency of rotation of the wheel.

[0140] At block 1806, the energy generated by the energy harvester may be transmitted to a device of the smart wheel sensor system. As described above, the energy may be transmitted to the device via, for example, an electrically conductive component. The electrically conductive component may be any type of conductor configured to transmit the energy generated by the energy harvester, such as a wire, ribbon, or pin made of a conductive material, to transmit the energy from the energy harvester to the device.

[0141] At block 1808, a device connected to the electrically conductive component may be powered by the energy generated by the energy harvester. The device may be, for example, a sensor or an energy storage medium of a smart wheel sensor system. Thus, the energy harvester may be part of a smart wheel sensor system to provide power to at least one energy storage medium or sensor of the smart wheel sensor system. The smart wheel sensor system may include multiple types of sensors, each of which may be configured to collect different types of smart wheel sensor system data. For example, the smart wheel sensor system may include a height sensor configured to generate air pressure sensor data and / or deflection of the inner surface of the tire, as described above; an acoustic sensor configured to generate acoustic sensor data; an image sensor configured to generate image sensor data; a gas sensor configured to generate gas sensor data; a magnetic sensor configured to generate magnetic sensor data; an accelerometer sensor configured to generate acceleration sensor data; a gyroscope sensor configured to generate gyroscope sensor data; and a humidity sensor configured to generate humidity sensor data.

[0142] Fig.14 An example method 2000 for preparing a piezoelectric component according to an embodiment of the present disclosure is illustrated. The operations of method 2000 presented below are intended to be illustrative. In some embodiments, method 2000 may be implemented with one or more additional operations not described and / or without one or more of the operations discussed. In addition, Fig.14 The order in which the operations of method 2000 are illustrated and described below is not intended to be limiting.

[0143] In step 2002, a load backing layer, a conductive bonding layer, a piezoelectric layer including a piezoelectric body, and an electrode layer are formed. In one example, the load backing layer includes a fiber reinforced composite material. In some embodiments, the fiber reinforced composite material includes a CFC material, wherein the CFC material includes a lattice interlaced structure or a quasi-isotropic structure, and the amount and orientation of the fibers in the CFC material can be configured during manufacturing to provide a higher elastic modulus. In some embodiments, the conductive bonding layer includes metal powder and resin for transferring the effect of the high elastic modulus in the CFC material from the load backing layer to the piezoelectric material layer.

[0144] At step 2004, the piezoelectric body of the piezoelectric layer is sintered. In some embodiments, the piezoelectric body is sintered by first forming a lead zirconate titanate (PZT) mold using a dry pressing process including polyvinyl pyrrolidone (PVP) as a binder, and then sintering the PZT mold at a temperature of 1100° C. to 1250° C. for 2 to 24 hours.

[0145] In step 2006, a composite slurry is applied to the piezoelectric body to form an interface layer. In some embodiments, the composite slurry is applied using a dip coating process or a screen printing process. In some examples, as described above, the material of the composite slurry used to form the interface layer 1106 is determined based on the material of the piezoelectric body. In one example, the piezoelectric body includes a Bi-based piezoelectric material, and therefore, the interface layer is configured to include a Bi-based glass frit or a Bi-based slurry. In another example, the piezoelectric body includes a Pb-based piezoelectric material, and therefore, the composite slurry is configured to include lead monoxide (PbO), lead acetate (Pb(CH3COO)2), or a Pb-based glass frit, wherein the mass fraction of the Pb-based glass frit in the Pb composite slurry is in the range of about 3% to about 10% to form voids in the interface layer. In some embodiments, the voids in the interface layer reduce the stress level in the interface layer, which makes the piezoelectric component less fragile and less prone to fatigue cracking and delamination.

[0146] At step 2008, the piezoelectric body is dried. In some embodiments, the piezoelectric body is dried at a temperature of about 50°C to about 80°C for a duration of 1 to 30 hours.

[0147] In step 2010, a metal paste is applied on the composite paste to form a metal layer. In some embodiments, the metal paste includes a silver (Ag) paste and is applied to the surface of the composite paste applied on the piezoelectric body. In some examples, the metal paste also includes a Pb-based glass frit.

[0148] At step 2012, the metal layer, the composite paste, and the piezoelectric body formed from the metal paste are sintered. In some embodiments, the metal layer, the composite paste, and the piezoelectric body are sintered at a temperature of about 300°C to about 800°C for a duration of 0.5 to 4 hours.

[0149] In step 2014, the surface layer of the fiber reinforced composite material in the load backing layer is removed. In some examples, the surface layer of the CFC material includes a resin layer. In some embodiments, the surface layer is removed so that the CFC material is exposed to the surface of the load backing layer. The surface layer can be removed by a mechanical etching process or a laser etching process. Examples of mechanical etching processes for removing the surface layer include chemical mechanical polishing, milling processes, lathe processing, and waterproof sandpaper polishing.

[0150] In step 2016, a load backing layer, a conductive bonding layer, a piezoelectric layer including a metal layer and an interface layer, and an electrode layer are stacked in a stacking process. In some embodiments, the stacking process is performed by stacking the load backing layer, the conductive bonding layer, the piezoelectric layer including a metal layer and an interface layer, and the electrode layer simultaneously at a pressure of about 0.1 to 2.0 MPa and a temperature of about 120 to 170° C. for a duration of about 5 to 100 seconds using a hydraulic hot press. In some examples, the stacked layers are transferred to a vacuum furnace and cured at a temperature of about 120 to 170° C. for a duration of about 15 to 120 seconds. In some embodiments, the conductive bonding layer is used to bond the load backing layer, the piezoelectric layer, and the electrode layer.

[0151] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only, not as limitations. Similarly, various drawings may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention is not limited to the example architectures or configurations shown, but can be implemented using various alternative architectures and configurations. In addition, as will be understood by those of ordinary skill in the art, one or more features of an embodiment may be combined with one or more features of other embodiments described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

[0152] It should also be understood that any reference to an element using numbers such as "first", "second" and the like herein does not generally limit the number or order of these elements. Instead, these numbers can be used herein as a convenient means of distinguishing two or more elements or instances of elements. Therefore, a reference to a first element and a second element does not mean that only two elements can be used, or that the first element must be before the second element in some way.

[0153] In addition, it will be understood by those skilled in the art that information and signals may be represented using any of a variety of different techniques and techniques. For example, data, instructions, commands, information, signals, bits, and symbols that may be mentioned in the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0154] It should also be appreciated by those of ordinary skill in the art that any of the various illustrative logical blocks, modules, processors, devices, circuits, methods, and functions described in conjunction with the various aspects disclosed herein may be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of both that may be designed using source code or some other technique), various forms of programs or design code containing instructions (which, for convenience, may be referred to herein as "software" or "software modules"), or a combination of both. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the specific application and the design constraints imposed on the overall system. An experienced technician may implement the described functionality in various ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0155] In addition, it will be understood by those of ordinary skill in the art that the various illustrative logic blocks, modules, devices, components, and circuits described herein may be implemented within or performed by an integrated circuit (IC), which may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logic blocks, modules, and circuits may also include antennas and / or transceivers to communicate with various components within a network or within a device. A general-purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration for performing the functions described herein.

[0156] If implemented in software, the function may be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the method or algorithm disclosed herein may be implemented as software stored on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium capable of transferring a computer program or code from one place to another. The storage medium may be any available medium that a computer can access. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage device, or any other medium that can be used to store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0157] In this document, the term "module" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. In addition, for the purpose of discussion, each module is described as a discrete module; however, as is apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according to an embodiment of the present invention.

[0158] In addition, memory or other storage devices and communication components can be used in embodiments of the present invention. It should be appreciated that, for clarity, the above description describes embodiments of the present invention with reference to different functional units and processors. However, it is apparent that any suitable distribution of functions between different functional units, processing logic elements or domains can be used without detracting from the present invention. For example, functions shown as being performed by separate processing logic elements or controllers can be performed by the same processing logic element or controller. Therefore, references to specific functional units are only references to suitable devices for providing the functions, rather than indicating a strict logical or physical structure or organization.

[0159] Various modifications to the implementations described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the implementations shown herein, but should be given the broadest scope consistent with the novel features and principles disclosed herein, as described in the claims below.

Claims

1. An energy harvesting module, comprising: A piezoelectric assembly configured to generate energy in response to a mechanical strain imparted on the piezoelectric assembly, wherein: The piezoelectric component is configured to deform when subjected to mechanical strain, and The piezoelectric assembly includes a piezoelectric material layer, one or more conductive bonding layers, a load backing layer, and one or more electrode layers, wherein the load backing layer includes a fiber reinforced composite material.

2. The energy harvesting module of claim 1 , wherein the one or more electrode layers include a first electrode layer, the one or more conductive bonding layers include a first conductive bonding layer, and wherein: A first conductive bonding layer is vertically above and in direct contact with the load backing layer, and The piezoelectric material layer is vertically above the first conductive bonding layer and directly contacts the first conductive bonding layer, and the piezoelectric material layer is horizontally surrounded by the first electrode layer.

3. The energy harvesting module of claim 1, wherein the fiber-reinforced composite material comprises at least one of the following: a carbon fiber composite material, a glass fiber composite material, a carbon nanotube-reinforced composite material, a graphene-reinforced composite material, and a ceramic-based composite material.

4. The energy harvesting module according to claim 2, wherein the fiber reinforced composite material is in direct contact with the first conductive bonding layer by removing a surface layer of the fiber reinforced composite material, wherein removing the surface layer comprises a mechanical etching, ablation, chemical etching or laser etching process. 5 . The energy harvesting module of claim 3 , wherein the fiber reinforced composite material comprises an elastic modulus, wherein the elastic modulus after the surface layer is removed is higher than the elastic modulus before the surface layer is removed.

6. The energy harvesting module of claim 2, wherein the one or more electrode layers include a second electrode layer, the one or more conductive bonding layers include a second conductive bonding layer, and wherein: A second conductive bonding layer is vertically above the piezoelectric material layer and directly contacts the piezoelectric material layer, and The second electrode layer is vertically above the second conductive bonding layer and directly contacts the second conductive bonding layer.

7. The energy harvesting module of claim 1, wherein the one or more conductive bonding layers comprise metal powder and resin.

8. An energy harvesting module, comprising: A piezoelectric assembly configured to generate energy in response to a mechanical strain imparted on the piezoelectric assembly, wherein: The piezoelectric component is configured to deform when subjected to mechanical strain, and The piezoelectric assembly includes a piezoelectric material layer, one or more conductive bonding layers, a load backing layer, one or more electrode layers, and one or more metal layers, wherein the load backing layer includes a fiber reinforced composite material.

9. The energy harvesting module of claim 8, wherein the one or more metal layers include a first metal layer, the one or more electrode layers include a first electrode layer, and the one or more conductive bonding layers include a first conductive bonding layer, wherein: A first conductive bonding layer is vertically above and in direct contact with the load backing layer, The first metal layer is vertically above the first conductive bonding layer and directly contacts the first conductive bonding layer, wherein the first metal layer is electrically connected to the first conductive bonding layer, and The piezoelectric material layer is vertically above the first metal layer, and the piezoelectric material layer is horizontally surrounded by the first electrode layer.

10. The energy harvesting module of claim 9, wherein the piezoelectric component further comprises one or more interface layers, wherein the one or more interface layers comprises a first interface layer, wherein: The first interface layer is vertically above and in direct contact with the first metal layer, and The piezoelectric material layer is vertically above the first interface layer and directly contacts the first interface layer.

11. The energy harvesting module of claim 9, wherein the one or more metal layers include a second metal layer, the one or more electrode layers include a second electrode layer, and the one or more conductive bonding layers include a second conductive bonding layer, wherein the second metal layer is vertically above the piezoelectric material layer. 12 . The energy harvesting module of claim 11 , wherein the second conductive bonding layer is vertically above the second metal layer and directly contacts the second metal layer, wherein the second conductive bonding layer is electrically connected to the second metal layer. 13 . The energy harvesting module of claim 8 , wherein the one or more metal layers include a silver (Ag) metal layer, a copper (Cu) metal layer, an aluminum (Al) metal layer, or a gold (Au) metal layer.

14. The energy harvesting module of claim 12, wherein the one or more interface layers comprise amorphous lead oxide or amorphous bismuth oxide.

15. The energy harvesting module of claim 14, wherein the one or more interface layers include voids.

16. A method comprising: forming a load-bearing backing layer comprising a fiber-reinforced composite material, wherein the fiber-reinforced composite material comprises a surface layer, wherein the surface layer comprises a resin layer; forming a conductive bonding layer; forming a piezoelectric material layer including a piezoelectric body; forming an electrode layer; Sintering the piezoelectric body in the piezoelectric material layer; Applying a composite slurry on the piezoelectric body to form an interface layer; drying the composite slurry on the piezoelectric body; applying a metal slurry on the composite slurry to form a metal layer; as well as The metal layer and the composite slurry are sintered.

17. The method according to claim 16, further comprising: The surface layer of the fiber reinforced composite material is removed by mechanical etching, ablation, chemical etching or laser etching process.

18. The method according to claim 17, further comprising: stacking the conductive bonding layer on the load-bearing backing layer; stacking the piezoelectric material layer on the conductive bonding layer; as well as The electrode layer is stacked on the piezoelectric material layer.

19. The method of claim 16, wherein: When the piezoelectric body includes a lead (Pb)-based piezoelectric material, the composite slurry includes lead monoxide (PbO), lead acetate (Pb(CH3COO)2) or a Pb-based glass frit, wherein the mass fraction of the Pb-based glass frit in the composite slurry is in the range of about 3% to about 10% to form voids in the interface layer.

20. The method of claim 16, wherein: When the piezoelectric body includes a bismuth (Bi)-based piezoelectric material, the composite paste includes a Bi-based glass frit or a Bi-based paste.

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