Microelectromechanical system (MEMS) rectifier and energy storage device for energy harvesting
The MEMS rectifier addresses the challenge of capturing low RF energy by generating and storing power using piezoelectric vibrations, ensuring reliable power to IoT devices in energy-scarce settings.
Patent Information
- Application Number
- JP2025175621
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-02
- Filing Date
- 2025-10-17
- Publication Date
- 2026-01-27
AI Technical Summary
Existing technologies struggle to efficiently capture and store low levels of radio frequency (RF) energy for powering IoT devices, particularly in environments with limited energy availability.
A MicroElectroMechanical Systems (MEMS) rectifier with a thin-film piezoelectric layer that vibrates in response to RF signals, generating energy through piezoelectric properties and storing it in capacitors or mechanically, using a sub-board configuration with a gap to facilitate contact and current flow.
The MEMS rectifier enhances energy capture efficiency, enabling consistent power supply to IoT devices even in low-energy environments, offering flexibility and wider energy capture range through parallel use with semiconductor rectifiers.
Smart Images
Figure 2026012804000001_ABST
Abstract
Description
[Technical Field]
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and benefit of the filing dates of U.S. Patent Application No. 17 / 901,988, filed September 2, 2022, and U.S. Provisional Patent Application No. 63 / 273,525, filed October 29, 2021, the entire disclosures of which are incorporated herein by reference. [Background technology]
[0002] The Internet of Things (IoT) is the internetworking of physical objects, such as products, packaging, vehicles, and buildings, that are embedded with electronic components for network connectivity. The embedded components enable the objects to detect other objects, be detected by other objects, collect data, and / or transmit data. In some examples, the embedded components may include tags or labels attached to the physical objects. These tags or labels may be passive or active. The internetworking capabilities may be leveraged to track the location of the physical objects. Summary of the Invention
[0003] An embodiment of the present disclosure provides an electronic device including a MicroElectroMechanical System (MEMS) rectifier. The MEMS rectifier includes a main board having one or more radio frequency (RF) inputs configured to receive RF signals and a first electrical contact. The MEMS rectifier also includes a sub-board disposed parallel to the main board with a gap therebetween. The sub-board has a thin-film piezoelectric layer, a second electrical contact disposed opposite the first electrical contact, and a ground plane. The sub-board is configured to vibrate when an RF signal is received at the one or more RF inputs, and the thin-film piezoelectric layer is configured to generate energy due to the vibration and the piezoelectric properties of the thin-film piezoelectric layer.
[0004] In one example, the electronic device also includes an energy storage device configured to receive and store the generated energy. In this example, the energy storage device optionally includes one or more capacitors. In another example, the generated energy is configured to flow from the second electrical contact to the first electrical contact when vibration of the sub-board brings the second electrical contact into contact with the first electrical contact. In this example, a separate electronic device is optionally connected to the first electrical contact and configured to receive charge from the MEMS rectifier via the first electrical contact.
[0005] In a further example, the sub-board is configured to vibrate at a resonant frequency within a particular frequency band, and the RF signal is also within the particular frequency band. In yet another example, the gap is packaged in a vacuum. In yet another example, the MEMS rectifier is in a chip having monolithic integration of piezoelectric material, electrostatic MEMS, and solid-state components.
[0006] Another aspect of the present disclosure provides a radio frequency (RF) energy harvesting method that includes receiving an RF signal via one or more RF inputs of a microelectromechanical systems (MEMS) rectifier, vibrating a sub-board of the MEMS rectifier when the RF signal is received by the one or more RF inputs, the sub-board including a piezoelectric material, generating energy via the vibration of the sub-board and properties of the piezoelectric material, and storing the generated energy.
[0007] In one example, the storage of the generated energy occurs in the mechanical domain. In another example, the storage of the generated energy occurs in an energy storage device. In this example, the energy storage device optionally includes one or more capacitors.
[0008] In a further example, the method also includes using vibration of the sub-board to contact first electrical contacts on the sub-board with second electrical contacts on a main board of the MEMS rectifier, the main board being positioned parallel to the sub-board with a gap therebetween, and generating an electric current using energy generated when the first electrical contacts contact the second electrical contacts. In this example, contacting the first electrical contacts with the second electrical contacts optionally includes increasing an amplitude of the vibration of the sub-board. Also in this example, the method also optionally includes using the generated electric current to power an electronic device. Furthermore, in this example, the method also optionally includes processing the generated electric current to accumulate charge before powering the electronic device. Also in this example, the method also optionally includes processing the generated electric current to meet requirements for powering the electronic device.
[0009] A further aspect of the present disclosure provides a method for fabricating a microelectromechanical systems (MEMS) rectifier, the method including: mounting first electrical contacts and one or more radio frequency (RF) inputs on a main board; mounting second electrical contacts on a sub-board, the sub-board including a ground plane; and mounting the sub-board to the main board with a gap therebetween, such that the second electrical contacts face the first electrical contacts across a gap and the sub-board is parallel to the main board.
[0010] In one example, attaching the sub-board to the main board includes configuring the sub-board to vibrate at a resonant frequency within the frequency band. In another example, the method also includes fabricating at least a portion of the sub-board or the main board using an integrated circuit fabrication process. [Brief explanation of the drawings]
[0011] [Figure 1A] FIG. 1 is a functional diagram of a micro-electro-mechanical systems rectifier according to aspects of the present disclosure. [Figure 1B]1 is a pictorial diagram of a micro-electro-mechanical systems rectifier according to an aspect of the present disclosure. [Figure 2] FIG. 1 is a functional diagram of an exemplary system including a rectifier, according to aspects of the present disclosure. [Figure 3] FIG. 1 is a pictorial diagram of an exemplary network, according to an aspect of the present disclosure. [Figure 4] FIG. 3 is a functional diagram of the example network in FIG. 2 according to an aspect of the present disclosure. [Figure 5] FIG. 1 is a flow diagram of an exemplary method according to an aspect of the present disclosure. [Figure 6] FIG. 10 is a flow diagram of another exemplary method according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0012] overview The present technology relates to a rectifier for radio frequency (RF) energy. The rectifier may include a microelectromechanical system (MEMS) resonator configured to vibrate in response to an RF modulation frequency. Using piezoelectric materials, the nonlinearity of electrostatic forces may be used to rectify the captured RF signal. This mechanical capture of energy may be more sensitive than using diodes or other solid-state technologies. As a result, in addition to or instead of using solid-state technology, piezoelectric RF energy harvesting may be used to capture and store lower levels of RF energy in the environment than using solid-state electronics alone.
[0013] The rectifier may include a main board including one or more RF inputs and a first electrical contact. The one or more RF inputs may be configured to receive RF signals, such as from an antenna. The RF signals may be in a specific frequency band. For example, the RF signals may include a cellular band of 750, 850, or 1900 MHz, an ISM band of 900 MHz, 2.4, or 5 GHz, and / or an AFC band of 3.5 or 6 GHz. The rectifier may also include a sub-board disposed parallel to the main board with a small gap therebetween. The sub-board may be secured in place using a first anchor at a first end and a second anchor at a second end. The sub-board may include a thin-film piezoelectric layer, a second electrical contact, and a ground plane. The thin-film piezoelectric layer may include crystalline aluminum nitride (AlN) and / or other materials having piezoelectric properties. The dimensions of the sub-board may be configured based on the specific frequency band to be captured. In some examples, the sub-board may include a material other than AlN having piezoelectric properties. The second electrical contact may be positioned opposite the first electrical contact. The small gap between the main board and the sub-board may be a vacuum or may be filled with a finite amount of air.
[0014] The sub-board is configured to vibrate at a resonant frequency when an RF signal is received by one or more RF inputs. In particular, the dimensions, material, and other characteristics of the sub-board may be configured to enable the sub-board to vibrate at a resonant frequency within a particular frequency band. The vibration of the sub-board may increase in amplitude over time when an RF signal is received.
[0015] Energy can be generated due to the vibrations and the piezoelectric properties of AlN. The generated energy can be stored and stored in a mechanical domain in the form of vibrations of the board (e.g., vibration amplitude). Alternatively, the generated energy can be stored and stored in an energy storage device, such as one or more capacitors.
[0016] Energy can be stored until the amplitude of the vibration allows the second electrical contact to touch the first electrical contact, and when the first and second electrical contacts touch, charge can flow from the second electrical contact to the first electrical contact, generating an electric current.
[0017] The first electrical contact may be connected to an electronic device. Thus, the generated current can flow from the first electrical contact to the electronic device to power the electronic device. In some cases, the connection between the electrical contact and the electronic device may include an energy storage device, such as one or more capacitors, to store charge before powering the electronic device. In other cases, the connection may include a transformer or filter configured to prepare the current to meet the requirements for powering the electronic device. In some examples, the rectifier may be integrated with the transformer or filter in a single component.
[0018] The MEMS rectifiers described herein can capture very low levels of RF energy in the environment. The increased sensitivity provided by the MEMS resonators can enable more energy to be captured at a more efficient rate. When used in connection with a tracking system, the MEMS rectifiers enable more consistent powering of tracking system components in areas with lower levels of energy in the environment. Additionally, because the energy harvesting function can be at least partially delegated to the MEMS rectifier, the configuration of the tracking system components becomes more flexible. The MEMS rectifiers can provide access to minute amounts of available energy, which can also be used in parallel with semiconductor rectifiers that operate only at higher incident power levels to form an overall system that captures a wider range of energy at a range of efficiencies.
[0019] System Example 1A and 1B are functional and pictorial diagrams of a MEMS rectifier 100. The rectifier 100 includes a main board 102 including one or more RF inputs 104 and a first electrical contact 106. The one or more RF inputs 104 may be configured to receive RF signals, such as from an antenna. The one or more RF inputs 104 may be configured to receive RF signals having a specific frequency band. For example, the specific frequency band may include the 750, 800-1000, or 1900 MHz cellular band, the 2.4 or 5 GHz ISM band, and / or the 3.5 or 6 GHz AFC band. When the RF signal has a frequency within the specific frequency band, the rectifier 100 can oscillate to generate a current as described herein. The first electrical contact 106 may be connected to an electronic device 150 and configured to output a current from the rectifier 100 to the electronic device 150.
[0020] The rectifier 100 also includes a sub-board 112 positioned parallel to the main board 102 with a small gap therebetween. The sub-board 112 is secured in position using a first anchor 110a at a first end and a second anchor 110b at a second end. The sub-board 112 includes a thin-film crystalline aluminum nitride (AlN) 114 having piezoelectric properties, a second electrical contact 116, and a ground plane 118. The dimensions of the sub-board 112 can be configured based on the specific frequency band to be captured. In some examples, the sub-board can include a material other than AlN having piezoelectric properties. The second electrical contact 116 is positioned opposite the first electrical contact 106.
[0021] The first electrical contact 106 and the second electrical contact 116 may be raised portions on the main board 102 and the sub-board 112, respectively. The raised portions may be sharp contact points. The raised portions may be formed using a combination of self-terminating etching into small openings in a mask layer followed by deposition of a top layer. Other known methods of forming raised electrical contacts on a board may be used in addition to or instead of this combination.
[0022] The gap between the second electrical contact 116 and the first electrical contact 106 can be minimized so that a lower threshold of RF energy is required for actuation, resulting in contact between the electrical contacts. For example, the gap between the contacts or between the sub-board and the main board can be 5 nm, 100 nm, or any dimension in between. The size of the gap can be formed or adjusted using thin-film techniques such as LPCVD or ALD films. The small gap between the main board and the sub-board can be a vacuum or filled with air. When the small gap is a vacuum, the rectifier 100 can achieve a higher Q-factor resonance, which increases the efficiency of rectification.
[0023] The combination of the main board 102 and the sub-board 112 constitutes the resonator portion of the rectifier 100. For example, the sub-board 112 is configured to vibrate at a resonant frequency in response to RF signals received by one or more RF inputs. In particular, the sub-board 112 can have dimensions, materials, and other characteristics that enable the sub-board 112 to vibrate at a resonant frequency within a particular frequency band. The vibration of the sub-board 112 can increase in amplitude over time when an RF signal is received. Due to the piezoelectric properties of the material of the sub-board 112, energy can be generated from the vibration of the sub-board 112. The generated energy can be stored and accumulated in a mechanical domain, such as the amplitude of the vibration. Alternatively, the rectifier 100 can include an energy storage device, such as one or more capacitors, configured to receive and store the energy generated from the vibration of the sub-board 112. In some implementations, the rectifier 100 described above can be included on a monolithic chip. In other implementations, a multi-chip module can be created using multiple rectifiers.
[0024] The sub-board 112 may be configured to store energy in a mechanical field, increasing in amplitude until the second electrical contact 116 contacts the first electrical contact 106. When the first and second electrical contacts make contact, charge can flow from the second electrical contact 116 to the first electrical contact 106, generating a current. The generated current can then flow from the first electrical contact 106 to the electronic device 150 connected to the first electrical contact, powering the electronic device. In some cases, the connection between the first electrical contact and the electronic device may include an energy storage device, such as one or more capacitors, to store charge before powering the electronic device. In other cases, the connection may include a transformer or filter configured to prepare the current to meet the requirements for powering the electronic device. In some examples, the rectifier may be integrated with the transformer or filter in a single component.
[0025] The lateral size of the rectifier 100 may be in the range of 5 μm to 50 μm, but may vary from this range as needed for different frequencies and situations. Rectifiers with larger widths have lower bending stiffness (or lower stiffness) and therefore lower spring constants than rectifiers with smaller widths. Wider rectifiers may allow for higher motion generated by piezoelectric forces, but due to their lower stiffness, may be more sensitive to vibration-induced contact events between the electrical contacts. Therefore, the dimensions of the rectifier may be selected to provide a target bending stiffness or stiffness that provides maximum energy output while also preventing environmental trigger events.
[0026] In some examples, the electronic device 150 connected to the rectifier 100 may be one or more components in a tracking system, such as the tracking system 200 shown in FIG. 2. The tracking system may include multiple tracking devices, such as identifier tags or sensors, and electronic components, such as a reader. As shown in FIGS. 2A and 2B, the tracking system 200 may include multiple identifier tags 204 (e.g., identifier chips) and a reader 206. Each identifier tag may be attached to an item to be tracked, such as a package. Thus, the rectifier 100 may capture RF energy 210 in an environment in which the tracking system 200 is implemented and provide power to one or more of the system's electronic components.
[0027] After capturing energy 210 from the environment, a given rectifier 100 can transmit current to one or more identifier tags 204. As shown in Figure 2, current is transmitted from MEMS rectifier 100a to identifier tag 204a, from MEMS rectifier 100b to identifier tag 204b, from MEMS rectifier 100c to identifier 204c, from MEMS rectifier 100d to identifier 204d, and from MEMS rectifier 100e to identifier 204e. When powered, multiple passive tags 204 can emit signals indicative of their locations.
[0028] The reader 206 may be a computing device configured to detect signals emitted by the plurality of identifier tags 204 and then store and / or transmit data related to the locations of the detected tags. In some implementations, the reader 206 may be connected to a MEMS rectifier to receive power. The reader 206 may include one or more processors 214, memory 216, and other components typically present in a general-purpose computing device.
[0029] The one or more processors 214 may be any conventional processor, such as a commercially available CPU. Alternatively, the one or more processors may be dedicated devices, such as ASICs, or other hardware-based processors, such as field programmable gate arrays (FPGAs). While FIG. 2 functionally depicts the processor, memory, and other elements of reader 206 as being within the same block, it will be understood by those skilled in the art that a processor, computing device, or memory may actually include multiple processors, computing devices, or memories that may or may not be housed within the same physical enclosure. For example, memory may be a hard drive or other storage medium located in a different enclosure than that of reader 206. Thus, reference to a processor or computing device will be understood to include reference to a collection of processors or computing devices or memories that may or may not operate in parallel.
[0030] Memory 216 stores information accessible by one or more processors 214, including data 217 and instructions 218 that can be executed or otherwise used by processor 214. Memory 216 may be any type of memory capable of storing information accessible by a processor, including computing device-readable media or other media that store data that can be read using an electronic device, such as a hard drive, memory card, ROM, RAM, DVD or other optical disk, and other writable and read-only memory. Systems and methods may include different combinations of the above, whereby different portions of the instructions and data are stored on different types of media.
[0031] Data 217 may be retrieved, stored, or modified by processor 214 according to instructions 218. For example, although claimed subject matter is not limited to any particular data structure, data may be stored in computing device registers, in a relational database as a table with multiple different fields and records, in an XML document, or in a flat file. This data may be formatted in a format readable by any computing device.
[0032] The instructions 218 may be any set of instructions that are executed by a processor directly (e.g., machine code) or indirectly (e.g., script). For example, the instructions may be stored as computing device code on a computing device-readable medium. In this regard, the terms "instructions" and "program" may be used interchangeably herein. The instructions may be stored in object code format for direct processing by a processor, or in any other computing device language, including a script or a collection of independent source code modules that are interpreted on demand or pre-compiled. The functions, methods, and routines of the instructions are described in detail below.
[0033] 3 and 4 are pictorial and functional diagrams, respectively, of an exemplary system 300 that includes multiple computing devices 310, 320, 330, 340 and a storage system 350 connected via a network 360. System 300 also includes passive tags 204a, 204b and a reader 206. For simplicity, only a few tags and computing devices are shown, although a typical system may include many more.
[0034] Using a client computing device, a user, such as user 322, 332, 342, can view location data on a display, such as display 324, 334, 344, of computing device 320, 330, 340. As shown in FIG. 4 , each client computing device 320, 330, 340 may be a personal computing device intended for use by user 322, 332, 342 and may include all components typically used in connection with a personal computing device, including one or more processors (e.g., a Central Processing Unit (CPU)), memory (e.g., RAM and an internal hard drive) for storing data and instructions, a display, such as display 324, 334, 344 (e.g., a monitor with a screen, a touchscreen, a projector, a television, or other device operable to display information), and user input devices 326, 336, 346 (e.g., a mouse, keyboard, touchscreen, or microphone). The client computing device may also include speakers, a network interface device, and all components used to connect these elements to each other.
[0035] Client computing devices 320, 330, and 340 may each comprise a full-sized personal computing device, or alternatively, a mobile computing device capable of wirelessly exchanging data with a server over a network such as the Internet. By way of example only, client computing device 320 may be a device such as a mobile phone or wireless-enabled PDA, a tablet PC, a wearable computing device or system, or a netbook capable of obtaining information over the Internet or other network. In another example, client computing device 330 may be a wearable computing system, shown as a wristwatch in FIG. 3 . By way of example, a user may input information using a miniature keyboard, keypad, microphone, a video signal using a camera, or a touchscreen.
[0036] Example of how to Various operations will now be described in addition to those described above and illustrated in the figures. It should be understood that the following operations do not have to be performed in the exact order described below.
[0037] 5 is an example flow diagram 500 including a method of operation for a MEMS rectifier according to some of the aspects described above. While FIG. 5 shows the blocks in a particular order, the order may be changed, multiple operations may be performed simultaneously, and operations may be added or omitted.
[0038] In block 502, an RF signal is received by one or more RF inputs 104 of the MEMS rectifier 100. In block 504, when the RF signal is received by the one or more RF inputs, the sub-board 112 of the MEMS rectifier 100 vibrates. In some cases, the RF signal is within a specific frequency band that causes the sub-board 112 to vibrate at a specific resonant frequency. The vibration of the sub-board 112 may increase in amplitude over time as the RF signal is received. In block 506, energy is generated due to the vibration and piezoelectric properties of the sub-board 112. In block 508, the generated energy is stored. The energy may be stored in a mechanical domain, such as the amplitude of the vibration, or in an energy storage device, such as one or more capacitors.
[0039] In block 510, electrical contacts on the sub-board 112 come into contact with electrical contacts on the main board 102 due to vibration of the sub-board 112. The main board 102 is positioned substantially parallel to the sub-board 112, with a gap between the main board 102 and the sub-board 112. Contact between the two electrical contacts can occur when the amplitude of the vibrating sub-board 112 can extend across the gap between the main board 102 and the sub-board 112. When contact between the electrical contacts occurs in block 512, charge can flow from the sub-board to the main board, generating a current.
[0040] In block 514, the generated current can flow from the main board 102 to the electronic device 150 to power the electronic device 150. As the generated current flows from the main board 102 to the electronic device 150, the current can flow through one or more electronic components to prepare the current to meet the requirements for powering the device. For example, the one or more electronic components can include an energy storage device, such as one or more capacitors, to store charge before powering the electronic device, or a transformer or filter to modify the current. In some examples, a rectifier can be integrated with a transformer or filter in a single component. When powered, the electronic device 150 can perform a function. For example, an identifier tag can emit a signal when powered.
[0041] figure 6 6 is an example flow diagram 600 including a method for fabricating a MEMS rectifier according to some of the aspects described above. The method may be performed by one or more computing devices controlling machines customized for the method steps. While FIG. 6 shows the blocks in a particular order, the order may be changed, multiple operations may be performed simultaneously, and operations may be added or omitted.
[0042] In block 602, the first electrical contact 106 and one or more RF inputs 104 may be mounted on the main board 102. In block 604, the second electrical contact 116 may be attached to the sub-board 112. The sub-board 112 may include a ground plane 118. In block 606, the sub-board 112 may be attached to the main board 102 with a gap between the sub-board 112 and the main board 102, thereby forming a resonating unit. The location of the attached sub-board may include the second electrical contact 116 directly across the gap from the first electrical contact 106 such that at least a portion of the second contact is located at a point on the sub-board that is the shortest distance from the first contact 106. When attached, the sub-board 112 may be substantially parallel to the main board 102. The sub-board 112 may be attached using one or more anchors 110. In some implementations, at least a portion of the main board 102 or sub-board 112 is fabricated using integrated circuit fabrication techniques. Alternatively, the MEMS rectifiers described herein, such as MEMS rectifier 100, can be fabricated as integrated circuits or monolithic chips using steps included in integrated circuit fabrication processes. The monolithic chip may include an integration of piezoelectric, electrostatic, and solid-state components. For example, piezoelectric material such as AlN, electrostatic circuits such as MEMS traces or other components, and CMOS circuits or electronics such as semiconductors can be integrated into a chip to form rectifier 100.
[0043] The MEMS rectifiers described herein can capture very low levels of RF energy in the environment. The increased sensitivity provided by the MEMS resonators can enable more energy to be captured at a more efficient rate. When used in connection with a tracking system, the MEMS rectifiers enable more consistent powering of tracking system components in areas with lower levels of energy in the environment. Additionally, because the energy harvesting function can be at least partially delegated to the MEMS rectifiers, the configuration of the tracking system components becomes more flexible.
[0044] Unless otherwise specified, the foregoing alternatives are not mutually exclusive and can be implemented in various combinations to achieve unique advantages. These and other variations and combinations of the above features can be utilized without departing from the subject matter defined by the claims, and the foregoing description of embodiments should be construed as illustrative, not limiting, of the subject matter defined by the claims. Furthermore, the provision of examples described herein, as well as terms such as "such as," "including," and the like, should not be construed as limiting the subject matter of the claims to any particular examples; rather, these examples are intended to illustrate only one of many possible embodiments. Furthermore, the same reference symbols on different drawings may identify the same or similar elements.
Claims
1. 1. An electronic device comprising a microelectromechanical system (MEMS) rectifier, the MEMS rectifier comprising: A main board, one or more radio frequency (RF) inputs configured to receive RF signals; a main board including a first electrical contact; a sub-board arranged parallel to the main board with a gap therebetween, a thin film piezoelectric layer; a second electrical contact disposed opposite the first electrical contact; a sub-board including a ground surface; Including, the sub-board is configured to vibrate when the RF signal is received at the one or more RF inputs; The thin-film piezoelectric layer is configured to generate energy by the vibrations and the piezoelectric properties of the thin-film piezoelectric layer.
2. The electronic device of claim 1 , further comprising an energy storage device configured to receive and store the generated energy.
3. The electronic device of claim 2 , wherein the energy storage device comprises one or more capacitors.
4. 2. The electronic device of claim 1, wherein the generated energy is configured to flow from the second electrical contact to the first electrical contact when vibration of the sub-board causes the second electrical contact to contact the first electrical contact.
5. The electronic device of claim 4 , wherein a separate electronic device is connected to the first electrical contact and configured to receive charge from the MEMS rectifier through the first electrical contact.
6. The electronic device of claim 1 , wherein the sub-board is configured to vibrate at a resonant frequency within a specific frequency band, and the RF signal is also within the specific frequency band.
7. The electronic device of claim 1 , wherein the gap is packaged in a vacuum.
8. The electronic device of claim 1 , wherein the MEMS rectifier is in a chip having a monolithic integration of piezoelectric material, electrostatic MEMS, and solid-state components.
9. 1. A radio frequency (RF) energy harvesting method, comprising: receiving an RF signal via one or more RF inputs of a microelectromechanical system (MEMS) rectifier; vibrating a sub-board of the MEMS rectifier when the RF signal is received by the one or more RF inputs, the sub-board comprising a piezoelectric material; generating energy by the vibration of the sub-board and the properties of the piezoelectric material; storing the generated energy; and A method comprising:
10. The method of claim 9 , wherein the storage of the generated energy occurs in the mechanical domain.
11. The method of claim 9 , wherein the storage of the generated energy occurs in an energy storage device.
12. The method of claim 11 , wherein the energy storage device comprises one or more capacitors.
13. utilizing the vibration of the sub-board to bring a first electrical contact on the sub-board into contact with a second electrical contact on a main board of the MEMS rectifier, the main board being disposed parallel to the sub-board with a gap therebetween; generating an electric current using the generated energy when the first electrical contact contacts the second electrical contact; The method of claim 9 further comprising:
14. 14. The method of claim 13, wherein bringing the first electrical contact into contact with the second electrical contact includes increasing an amplitude of the vibration of the sub-board.
15. The method of claim 13 , further comprising using the generated current to power an electronic device.
16. 16. The method of claim 15, further comprising processing the generated current to store charge before powering the electronic device.
17. 16. The method of claim 15, further comprising processing the generated current to meet requirements for powering the electronic device.
18. 1. A method of fabricating a microelectromechanical systems (MEMS) rectifier, comprising: Mounting a first electrical contact and one or more radio frequency (RF) inputs on a main board; attaching a second electrical contact to a sub-board, the sub-board including a ground plane; attaching the sub-board to the main board with the gap therebetween, in a position where the second electrical contacts face the first electrical contacts across a gap and the sub-board is parallel to the main board; A method comprising:
19. 20. The method of claim 18, wherein attaching the sub-board to the main board includes configuring the sub-board to vibrate at a resonant frequency within a frequency band.
20. 20. The method of claim 18, further comprising manufacturing at least a portion of the sub-board or the main board using an integrated circuit manufacturing process.