Micromechanical electrical signal amplifier
By utilizing the elastic beam and self-amplification effect of submicron-scale piezoresistive materials and piezoresistive resonators, the problem of low electrical signal response efficiency in MEMS devices is solved, and efficient amplification of electrical signals is achieved.
Patent Information
- Application Number
- CN202411671208.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2026-05-22
AI Technical Summary
Existing MEMS devices have low electromechanical conversion efficiency in response to electrical signals and cannot effectively amplify electrical signals.
An elastic beam made of submicron-scale piezoresistive material is used to amplify electrical signals through electrostatically driven displacement and mechanical resonance structure by utilizing the self-amplification effect of the piezoresistive resonator.
The amplification capability of electrical signals is improved, and the resonant quality factor of submicron-scale piezoresistive materials is several orders of magnitude higher than that of electrostatically driven mechanical structures.
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Figure CN122073466A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of microelectronics technology, and in particular to a microelectromechanical signal amplifier. Background Technology
[0002] Besides semiconductor transistors, many other materials and mechanical structures are used to process electrical signals. For example, surface acoustic wave (SAW) filters based on quartz or lithium niobate and bulk acoustic wave (BAW) filters based on aluminum nitride piezoelectric thin films are widely used in the communications field. Quartz or silicon crystal oscillators can also generate fixed-period electrical signals, serving as clock signals for electronic devices. In general, methods utilizing acoustic vibrations or micromechanical vibrations for electrical signal processing are widely used in the electronics industry.
[0003] Acoustic vibration elements are generally made of piezoelectric materials because piezoelectric conversion has high electromechanical conversion efficiency, making it particularly suitable for high-frequency, low-loss electrical signal filtering. Micromechanical vibration devices, on the other hand, are generally made of silicon, and their mechanical structure vibration is mostly driven by electrostatic force, known as capacitive MEMS devices. Their advantages include low anchor point loss resulting in a high quality factor, making them suitable as crystal oscillators for clock references or as inertial sensing devices sensitive to inertial motion. Their disadvantages include relatively small electrostatic force and low system electromechanical conversion efficiency. Piezoelectric and capacitive devices are widely used as filters or sensors in consumer electronics, but from the perspective of electrical signal processors, regardless of their electromechanical conversion efficiency, they do not amplify electrical signals.
[0004] Using micromechanical structures to amplify electrical signals was proposed by scientists in the first decade of the 21st century, when capacitive resonators were first discovered. However, at that time, the energy loss mechanism of capacitive resonators was not well understood. As research progressed, it was discovered that the electromechanical conversion efficiency of capacitive resonators was difficult to improve, and micromechanical amplifiers were no longer mentioned until the thermopiezoresistive effect was discovered. In 2007, Van Beek and colleagues at NXP Semiconductors Research Center, while studying resonators with a mass block structure supported by two beams of different widths, discovered the amplifying effect of the piezoresistive structure on the quality factor. In 2011, they published a paper in *Nature Physics*, providing a simple explanation of the thermo-piezoresistive effect: the piezoresistive beams expand thermally under electrothermal effects, pushing the mass block to move. The inertial force of the mass block pulls the piezoresistive beams, causing further deformation and reducing their resistance. The DC current flowing through the piezoresistive beams and the Joule heat from the changing resistance also decrease, forcing the structure to contract. After the mass block returns to its equilibrium point, it continues to compress the piezoresistive beams, increasing their resistance and Joule heat, causing the structure to expand again. Van Beek et al.'s research quickly attracted the attention of their peers. In 2010, Professor Pourkamali at the University of Denver systematically summarized the quality factor amplification effect of the I2BAR structure resonator, confirming the modulation effect of current on the quality factor of the thermo-piezoresistive resonator. That same year, they achieved self-oscillation of the thermo-piezoresistive resonator.
[0005] Although the mechanism of the thermo-piezoresistive effect and the related device structures are still being refined and explored, it is certain that the resonant quality factor of submicron-scale piezoresistive elastic beams driven by current is several orders of magnitude higher than that of electrostatically driven mechanical structures. Therefore, research on the application of submicron-scale piezoresistive elastic beams in electrical signal amplifiers is crucial. Summary of the Invention
[0006] (a) Technical problems to be solved
[0007] To address the problems of low electromechanical conversion efficiency and inability to effectively amplify electrical signals in existing MEMS devices, embodiments of this disclosure provide a microelectromechanical signal amplifier. This amplifier utilizes the self-amplification effect of a piezoresistive resonator to amplify the electrostatic force response displacement. The submicron-scale piezoresistive material elastic beam, under current-driven conditions, exhibits a resonance quality factor several orders of magnitude higher than that of electrostatically driven mechanical structures. By employing piezoresistive material as the material for both the first and second elastic beams, the amplification capability of the microelectromechanical signal amplifier is enhanced.
[0008] (II) Technical Solution
[0009] In view of the above problems, embodiments of this disclosure provide a microelectromechanical signal amplifier.
[0010] According to a first aspect of this disclosure, a microelectromechanical signal amplifier is provided, comprising: an electromechanical conversion structure for generating an electrostatically driven displacement; a mechanical resonant structure for generating an amplified electrical signal in response to the amplified electrostatically driven displacement; and a mechanical-to-electrical conversion structure for outputting the amplified electrical signal, wherein the mechanical resonant structure includes a first surface and a second surface disposed opposite to each other; the electromechanical conversion structure is connected to the first surface of the mechanical resonant structure; and the mechanical-to-electrical conversion structure is connected to the second surface of the mechanical resonant structure.
[0011] In some exemplary embodiments, the electromechanical conversion structure includes a first fixed structural member and a first movable structural member, wherein the first movable structural member is fixed to a first surface; the first movable structural member includes a first groove; and the first fixed structural member has a boss structure, with the small end of the boss structure located in the first groove.
[0012] In some exemplary embodiments, the mechanical-electric conversion structure includes a second fixed structure and a second movable structure, wherein the second movable structure is fixed to a second surface; the second movable structure includes a second groove; and the second fixed structure has a boss structure, with the small end of the boss structure located in the second groove.
[0013] In some exemplary embodiments, the mechanical resonant structure includes a first anchor point, a second anchor point, an elastic beam assembly, and a mass block, wherein the mass block is connected to the first anchor point and the second anchor point via the elastic beam assembly.
[0014] In some exemplary embodiments, the distance between the first movable structural member and the first fixed structural member is 1×10. -6 mm-1×10 -3 mm; the materials of the first movable structural member and the first fixed structural member include conductive materials; the spacing between the second fixed structural member and the second movable structural member is 1×10 mm. -6 mm-1×10 -3 mm; and the materials of the second fixed structural member and the second movable structural member include conductive materials.
[0015] In some exemplary embodiments, the elastic beam assembly includes a first elastic beam and a second elastic beam, wherein the width of both the first elastic beam and the second elastic beam is 1×10. -6 mm-1×10 -4 mm; the lengths of both the first and second elastic beams are several 1×10 mm. -5 mm-1×10 -2mm; the shape of the first elastic beam and the second elastic beam includes one of a straight beam, a folded beam or a curved beam; the material of the first elastic beam and the second elastic beam includes a piezoresistive material; and the material of the first anchor point, the second anchor point and the elastic beam assembly includes a conductive material or the same piezoresistive material as the first elastic beam and the second elastic beam.
[0016] In some exemplary embodiments, when the microelectromechanical signal amplifier is working, the circuit connection includes: a first fixed structure is connected to an excitation signal through a first capacitor, the other end of which is grounded; a first anchor point is connected to an active signal, the other end of which is grounded, the active signal being used to provide a DC voltage for the mechanical resonant structure; a second anchor point is connected to a resistor, the other end of which is grounded; and a second fixed structure outputs a signal through a second capacitor.
[0017] In some exemplary embodiments, the operation of the microelectromechanical signal amplifier includes: the electrical signal to be amplified is applied to a first fixed structural member of the electromechanical conversion structure through capacitive coupling to generate an electrostatic drive displacement; in response to the electrostatic drive displacement, a first DC current is generated on the mechanical resonant structure, and a DC voltage is applied to the mechanical resonant structure relative to the first and second fixed structural members to obtain the amplified electrical signal; and the amplified electrical signal is output through the second fixed structural member of the electromechanical conversion structure.
[0018] In some exemplary embodiments, the electromechanical conversion capability of the electromechanical conversion structure is related to the distance between the first fixed structural member and the first movable structural member, the capacitance of the first capacitor, the stiffness of the first elastic beam and the second elastic beam, the resonant frequency, and the DC voltage applied to the mechanical resonant structure; the electromechanical conversion capability of the mechanical-electric conversion structure is related to the distance between the second fixed structural member and the second movable structural member, the capacitance of the second capacitor, and the DC voltage applied to the mechanical resonant structure.
[0019] In some exemplary embodiments, the amplification capability of the mechanical resonant structure in response to electrostatically driven displacement is related to the size of the mechanical resonant structure, its piezoresistive characteristics, and the magnitude of the DC current flowing through it.
[0020] (III) Beneficial Effects
[0021] As can be seen from the above technical solutions, the microelectromechanical signal amplifier provided by the embodiments of this disclosure has at least one of the following beneficial effects:
[0022] (1) The electrostatic force response displacement is amplified by the self-amplification effect of the piezoresistive resonator. Since the piezoresistive resonator is limited by the nonlinearity of vibration, the output voltage is generally in the millivolt range. Therefore, the output of the detection capacitor (second capacitor) is increased to improve the amplitude of the output signal.
[0023] (2) The resonant quality factor of the submicron scale piezoresistive elastic beam under current drive can be improved by several orders of magnitude compared with the resonant quality factor of the electrostatically driven mechanical structure. Using piezoresistive material as the material of the first and second elastic beams can improve the amplification capability of the microelectromechanical signal amplifier. Attached Figure Description
[0024] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:
[0025] Figure 1 A schematic diagram illustrating the structure of a microelectromechanical signal amplifier according to an embodiment of the present disclosure is shown; and
[0026] Figure 2 The schematic diagram illustrates a working circuit diagram of a microelectromechanical signal amplifier according to an embodiment of the present disclosure.
[0027] Figure label:
[0028] 1-Electro-mechanical conversion structure; 11-First fixed structural component; 12-First movable structural component; 2-Mechanical-electric conversion structure; 21-Second fixed structural component; 22-Second movable structural component; 3-Mechanical resonance structure; 31-First anchor point; 32-Second anchor point; 33-Elastic beam assembly; 331-First elastic beam; 332-Second elastic beam; 34-Mass block. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.
[0030] Figure 1 The schematic diagram illustrates a microelectromechanical signal amplifier according to an embodiment of the present disclosure.
[0031] like Figure 1As shown, a microelectromechanical signal amplifier according to an embodiment of the present disclosure includes an electromechanical conversion structure 1 for generating electrostatic drive displacement; a mechanical resonant structure 3 for generating an amplified electrical signal in response to amplifying the electrostatic drive displacement; and a mechanical-to-electrical conversion structure 2 for outputting the amplified electrical signal. The mechanical resonant structure 3 includes a first surface and a second surface disposed opposite to each other. The electromechanical conversion structure 1 is connected to the first surface of the mechanical resonant structure 3; and the mechanical-to-electrical conversion structure 2 is connected to the second surface of the mechanical resonant structure 3.
[0032] In some exemplary embodiments, the electromechanical conversion structure 1 includes a first fixed structural member 11 and a first movable structural member 12, wherein the first movable structural member 12 is fixed to a first surface; the first movable structural member 12 includes a first groove; and the first fixed structural member 11 has a boss structure, with the small end of the boss structure located within the first groove. Optionally, the distance between the first movable structural member 12 and the first fixed structural member 11 is 1×10⁻⁶. -6 mm-1×10 -3 mm; the materials of the first movable structural member 12 and the first fixed structural member 11 include conductive materials. For example, there is a nanometer to micrometer scale spacing between the first movable structural member 12 and the first fixed structural member 11.
[0033] In some exemplary embodiments, the mechanical-to-electric conversion structure 2 includes a second fixed structural member 21 and a second movable structural member 22, wherein the second movable structural member 22 is fixed to a second surface; the second movable structural member 22 includes a second groove; and the second fixed structural member 21 has a boss structure, with the small end of the boss structure located within the second groove. Optionally, the distance between the second fixed structural member 21 and the second movable structural member 22 is 1×10⁻⁶. -6 mm-1×10 -3 mm; and the materials of the second fixed structure 21 and the second movable structure 22 include conductive materials. For example, there is a nanometer to micrometer scale spacing between the second fixed structure 21 and the second movable structure 22.
[0034] In some exemplary embodiments, the mechanical resonant structure 3 includes a first anchor point 31, a second anchor point 32, an elastic beam assembly 33, and a mass block 34, wherein the mass block 34 is connected to the first anchor point 31 and the second anchor point 32 via the elastic beam assembly 33. Optionally, the elastic beam assembly 33 includes a first elastic beam 331 and a second elastic beam 332, wherein the width of both the first elastic beam 331 and the second elastic beam 332 is 1×10. -6 mm-1×10 -4 mm; the lengths of both the first elastic beam 331 and the second elastic beam 332 are several 1×10 mm. -5 mm-1×10 -2mm; the shape of the first elastic beam 331 and the second elastic beam 332 includes one of a straight beam, a folded beam, or a curved beam; the material of the first elastic beam 331 and the second elastic beam 332 includes a piezoresistive material; and the materials of the first anchor point 31, the second anchor point 32, and the elastic beam assembly 33 include a conductive material or the same piezoresistive material as the first elastic beam 331 and the second elastic beam 332. For example, the width of the first elastic beam 331 and the second elastic beam 332 is on the scale of nanometers to hundreds of nanometers, and the length is on the scale of tens of nanometers to tens of micrometers.
[0035] Figure 2 The schematic diagram illustrates a working circuit diagram of a microelectromechanical signal amplifier according to an embodiment of the present disclosure.
[0036] like Figure 2 As shown, in the operation of a microelectromechanical signal amplifier according to an embodiment of this disclosure, the first fixed structure 11 is connected to the excitation signal AC through the first capacitor C1, and the other end of the excitation signal AC is grounded; the first anchor point 31 is connected to the active signal DC, and the other end of the active signal DC is grounded, the active signal DC being used to provide DC voltage for the mechanical resonant structure 3; the second anchor point 32 is connected to the resistor R1, and the other end of the resistor R1 is grounded; and the second fixed structure 21 outputs a signal through the second capacitor C2. GND1, GND2, and GND3 represent grounding.
[0037] The operation of the micro-mechanical electrical signal amplifier includes: the electrical signal to be amplified is applied to the first fixed structure 11 of the electro-mechanical conversion structure 1 through capacitive coupling, generating electrostatic drive displacement; in response to the electrostatic drive displacement, a first DC current is generated on the mechanical resonant structure 3, and at the same time, the first fixed structure 11 and the second fixed structure 21 apply a DC voltage to the mechanical resonant structure 3 to obtain the amplified electrical signal; and the amplified electrical signal is output through the second fixed structure 21 of the electro-mechanical conversion structure 2.
[0038] In this embodiment, the electromechanical conversion capability of the electromechanical conversion structure 1 is related to the distance between the first fixed structural member 11 and the first movable structural member 12, the capacitance of the first capacitor C1, the stiffness of the first elastic beam 331 and the second elastic beam 332, the resonant frequency, and the DC voltage applied to the mechanical resonant structure 3; the electromechanical conversion capability of the electromechanical conversion structure 2 is related to the distance between the second fixed structural member 21 and the second movable structural member 22, the capacitance of the second capacitor C2, and the DC voltage applied to the mechanical resonant structure 3. The amplification capability of the mechanical resonant structure 3 in response to electrostatically driven displacement is related to the size of the mechanical resonant structure 3, its piezoresistive characteristics, and the magnitude of the DC current flowing through the mechanical resonant structure 3.
[0039] This embodiment utilizes electrostatic force to drive the movement of a piezoresistive resonator. A certain current flows through the elastic beam of the piezoresistive resonator, and the self-amplification effect of the nanoscale piezoresistive resonator increases the vibration displacement of the piezoresistive resonator, thereby increasing the capacitance gap between the piezoresistive resonator and the detection capacitor (second capacitor C2). At this time, a higher DC voltage is applied to the piezoresistive resonator, resulting in a larger output signal at the detection capacitor port. This embodiment amplifies the electrostatic force response displacement by utilizing the self-amplification effect of the piezoresistive resonator. Since the piezoresistive resonator is limited by the nonlinearity of vibration, the output voltage is generally in the millivolt range; therefore, increasing the output of the detection capacitor increases the amplitude of the output signal.
[0040] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.
Claims
1. A microelectromechanical signal amplifier, characterized in that, include: Electromechanical conversion structure for generating electrostatically driven displacement; A mechanical resonant structure is used to respond to and amplify the electrostatically driven displacement, thereby generating an amplified electrical signal; as well as A mechanical-to-electrical conversion structure is used to output the amplified electrical signal. The mechanical resonance structure includes a first surface and a second surface disposed opposite to each other; The electromechanical conversion structure is connected to the first surface of the mechanical resonant structure; and The mechatronics conversion structure is connected to the second surface of the mechanical resonant structure.
2. The microelectromechanical signal amplifier according to claim 1, characterized in that, The electromechanical conversion structure includes a first fixed structural component and a first movable structural component. The first movable structural member is fixed to the first surface; The first movable structural member includes a first groove; and The first fixing structure is a boss structure, with the small end of the boss structure located in the first groove.
3. The microelectromechanical signal amplifier according to claim 2, characterized in that, The mechanical-to-electric conversion structure includes a second fixed structural component and a second movable structural component. The second movable structural member is fixed to the second surface; The second movable structural member includes a second groove; and The second fixing structure is a boss structure, with the small end of the boss structure located in the second groove.
4. The microelectromechanical signal amplifier according to claim 3, characterized in that, The mechanical resonance structure includes a first anchor point, a second anchor point, an elastic beam assembly, and a mass block. The mass block is connected to the first anchor point and the second anchor point via an elastic beam assembly.
5. The microelectromechanical signal amplifier according to claim 3, characterized in that, The distance between the first movable structural member and the first fixed structural member is 1×10. -6 mm-1×10 -3 mm; The materials of the first movable structural member and the first fixed structural member include conductive materials; The distance between the second fixed structural member and the second movable structural member is 1×10. -6 mm-1×10 -3 mm; and The materials of the second fixed structural member and the second movable structural member include conductive materials.
6. The microelectromechanical signal amplifier according to claim 4, characterized in that, The elastic beam assembly includes a first elastic beam and a second elastic beam. The widths of both the first and second elastic beams are 1×10. -6 mm-1×10 -4 mm; The lengths of both the first and second elastic beams are several 1×10. -5 mm-1×10 -2 mm; The shapes of the first elastic beam and the second elastic beam include one of a straight beam, a folded beam, or a curved beam; The materials of the first elastic beam and the second elastic beam include piezoresistive materials; and The materials of the first anchor point, the second anchor point, and the elastic beam assembly include conductive materials or the same piezoresistive materials as the first and second elastic beams.
7. The microelectromechanical signal amplifier according to claim 6, characterized in that, When the microelectromechanical signal amplifier is in operation, the circuit connection method includes: The first fixed structural component is connected to the excitation signal via a first capacitor, and the other end of the excitation signal is grounded; The first anchor point is connected to an active signal, the other end of which is grounded. The active signal is used to provide a DC voltage for the mechanical resonant structure. The second anchor point is connected to a resistor, the other end of which is grounded. The second fixed structure outputs a signal through the second capacitor.
8. The microelectromechanical signal amplifier according to claim 7, characterized in that, The operation of the microelectromechanical signal amplifier includes: The electrical signal to be amplified is applied to the first fixed structural component of the electromechanical conversion structure through capacitive coupling, generating electrostatic drive displacement; In response to the electrostatically driven displacement, a first direct current is generated on the mechanical resonant structure, and simultaneously, a direct current voltage is applied to the mechanical resonant structure relative to the first and second fixed structural members, resulting in an amplified electrical signal; and The amplified electrical signal is output through the second fixed structural component of the mechanical-to-electrical conversion structure.
9. The microelectromechanical signal amplifier according to claim 7, characterized in that, The electromechanical conversion capability of the electromechanical conversion structure is related to the distance between the first fixed structural member and the first movable structural member, the capacitance of the first capacitor, the stiffness of the first elastic beam, the stiffness of the second elastic beam, the resonant frequency, and the DC voltage applied to the mechanical resonant structure. The electromechanical conversion capability of the mechanical-electric conversion structure is related to the distance between the second fixed structural member and the second movable structural member, the capacitance of the second capacitor, and the DC voltage on the mechanical resonant structure.
10. The microelectromechanical signal amplifier according to claim 8, characterized in that, The amplification capability of the mechanical resonant structure in response to electrostatically driven displacement is related to the size of the mechanical resonant structure, the piezoresistive characteristics of the piezoresistive material, and the magnitude of the DC current flowing through the mechanical resonant structure.