Field Of Microelectromechanical Systems Research Articles

Dynamic process of wet etching using BOE solutions to control the etch rate, roughness, and surface morphology of a Z-cut α-quartz wafer

Quartz is a widely used material in the field of microelectromechanical systems (MEMS) for fabricating devices such as substrates, probes, and lenses; it is also indispensable as a resonator or oscillator for frequency control in communication and network technologies. However, its development is limited because it is difficult to fabricate an ideal profile for implementation in complex structures. In practice, wet etching is the most effective and extensive method for achieving the expected structure, although dry etching and other special machining techniques have also been investigated. In this study, the dynamic wet etching process was recorded using different ratios of buffered oxide etcher (BOE) solutions as the etchant to reveal the etching mechanism. The experiments were first designed considering the fabrication of samples, experimental conditions, and measurement indicators. Subsequently, the corresponding etch rate, roughness, and surface morphology were investigated to control the process parameters during wet etching. Different etchants exhibit varying etching rates and roughness properties. A smaller proportion of hydrofluoric acid in the BOE solution results in lower etch rate, and vice versa. The roughness (Ra) in the stable stage was not completely consistent with the tendency of the etch rate, whereas the surface morphology and dimensions of the pyramids rationally complied with the roughness trend. Additionally, the results suggested that the three following stages exist during the wet etching process of the z-cut α-quartz wafer; smooth, incremental, and stable. The analysis of the dynamic wet etching process in this study is beneficial for the structural design, manufacturing, and performance of quartz MEMS devices.

Influence of electrolytic plasma spatial distribution on nanoporous structure etching on 4H-SiC surface

Single-crystal SiC nanoporous structure has important applications in the field of micro electromechanical systems, chemical sensors and biomedical devices. However, SiC exhibits a strong chemical inertness due to the short interatomic distance and high binding energy, making it significantly challenging to fabricate nanoporous structure. Electrolytic plasma-assisted chemical etching (EPACE) based on electrochemical anodic oxidation and high-activity electrolytic plasma etching is an ideal method for SiC nanoporous structure etching. In which, the spatial distribution of electrolytic plasma has an important impact on EPACE performance, such as etching efficiency and stability. In order to analyze the impact mechanism, this paper studies EPACE in tool electrode mounting posture of vertical and horizontal types by visual observation, real-time recording of voltage-current waveforms during processing, and the morphology analysis of SiC nanoporous structure after etching. It can be found that in the vertical etching type, EPACE can proceed stably because the workpiece immersion depth is greater than the bubble accumulation thickness. However, in the horizontal etching type, bubbles accumulate seriously between the workpiece and the liquid surface, which may cause bubble cavitation and abnormal discharge, leading to damage to the etching surface. The etching current in the vertical etching type is about 1.3 times that of the horizontal etching type, indicating that the bubble mass transfer in the vertical etching type is faster and the etching impedance is smaller, which is beneficial to improve the etching efficiency and obtain a uniform nanoporous structure. Finally, a SiC nanoporous layer with a thickness of 10.6 μm was prepared at etching time t = 50 min in vertical etching type, and the etching efficiency was 212 nm/min. In addition, the prepared nanoporous structure (nanofiber) was connected to the SiC substrate, indicating that it has a good bonding strength.

Study on the overall performance of ZrO2 nanoparticle reinforced Co and CoP composite coating prepared by electrodeposition

Co coating and CoP alloy coating reinforced by ZrO2 nanoparticles are prepared on the surface of the brass substrate by DC electrodeposition to improve the magnetic property and corrosion resistance. The Co/ZrO2 and CoP/ZrO2 composite coating electrodeposited on the surface of brass can be used in the field of thin-film magnetic heads, thin-film sensors and electronic circuits. By comparing the performance of different cobalt-based alloy coatings, the influence of ZrO2 nanoparticles on the electrodeposition and performance of Co coating and CoP alloy coating is studied. It is found that cobalt electrodeposition is a typical irreversible process with diffusion control. The CoP alloy coating comprises about 81% Co and 19% P. However, the electrodeposited CoP/ZrO2 composite coating possesses about 86% Co, 3% P, and 11% Zr. The incorporation of a 15 g/L ZrO2 nanoparticle with the size of 50 nm is beneficial to improve the cobalt content and decrease the amount of phosphorus in the CoP/ZrO2 composite coating. The hardness of CoP alloy coating is about 350 HV. However, the surface hardness of Co/ZrO2 and CoP/ZrO2 composite coating is about 400 HV and 470 HV, respectively. All the cobalt-based coatings show cellular surface morphology. The ZrO2 nanoparticles incorporated in the cobalt coating can enter into the cobalt lattice or disperse at the grain boundary to refine the grain size and limit the displacement of magnetic domain to improve the corrosion resistance and coercivity extremely. It is found out that the electrodeposited CoP/ZrO2 composite coating has the best corrosion resistance with only 9.7 μA/cm2 corrosion current density and the largest coercivity of 665.1 Oe. The optimal corrosion resistance and good magnetic performance of prepared CoP/ZrO2 is a promising material in the field of microelectromechanical systems as micro pumps, magnetic read heads, micro motors, and so on.

Transfer of III-nitride epitaxial layers onto pre-patterned silicon substrates for the simple fabrication of free-standing MEMS

In recent years, the remarkable properties and potential applications of III-nitride (III-N) semiconductors have sparked a significant interest in the field of microelectromechanical systems (MEMS). Traditionally, III-N MEMS are fabricated through a process involving the epitaxial growth of III-N epilayers on a silicon substrate followed by etching the handle wafer to generate free-standing structures. In this study, we explore the potential of a relatively simple approach based on the two-dimensional (2D) material-based liftoff and transfer to fabricate III-N mechanical resonators. The methodology involves van der Waals epitaxy of III-N layers on 2D hexagonal-boron nitride (h-BN), which leverages the weak van der Waals adhesion between h-BN layers to lift off and transfer these layers from their original growth substrate to an alternative host substrate. The employed method is demonstrated by fabricating 600 nm thick GaN/AlGaN and 2.5 μm thick h-BN micro-resonators onto pre-patterned cavities etched in silicon substrates. These devices are characterized using laser Doppler vibrometry, enabling the observation of well-defined modes of vibration and resonant frequencies. Furthermore, finite element method simulations are performed to gain insights into the experimental observations and the mechanical properties of the transferred layers. This approach could be extended to transfer high-quality III-N MEMS devices onto various host substrates, including flexible substrates, and could be used to assess the mechanical properties of emerging III-N semiconductor materials.

Analytical Review on Enhancing Sustainability in microsystems by Integrating MEMS for Compact Design

By combining silicon-based microelectronics with micromachining technology, microelectromechanical systems (MEMS) have been identified as one of the most promising technologies for the 21st Century. With its microsystem-based devices and technologies, it will have a dramatic impact on the way we live and the way we live our lives. With an emphasis on both commercial applications and device fabrication methods, the paper provides an introduction to the field of MEMS. As well as discussing the range of MEMS sensors and actuators, the phenomena that MEMS devices can sense and act upon, and the major challenges facing the industry, the presentation discusses the challenges faced by the MEMS industry. An introduction to the field of MEMS is presented in this paper, which is divided into four sections. A section on MEMS introduces the reader to its definitions, history, current applications, and miniaturization-related issues. Photolithography, bulk micromachining, surface micromachining, and high-aspect-ratio micromachining are among the fundamental fabrication methods discussed in the second section, as well as assembly, system integration, and packaging of MEMS devices. A brief description of the basic principles of sensing and actuation mechanisms is provided in the third section, which discusses the range of MEMS sensors and actuators, as well as the phenomena that can be sensed or acted upon with MEMS devices. Toward the commercialization and success of MEMS, the final section illustrates the challenges facing the industry.

A DFT analysis on the superlubricity performance of structural superlubricity micro/nano-component on silicon-based surface

Friction and wear are important factors which limit the development of Micro-electromechanical Systems (MEMS). Therefore, the research and preparation of wear-resistant micro and nano-functional structures in the field of MEMS has profound importance. Structural superlubricity micro/nano-components (the atomic layers are in incommensurate contact, which means that the friction and wear rate is nearly zero when the layers slide) are expected to be the basic micro and nano functional structures for fabricating ultra wear-resistant MEMS. At present, there is a lack of research on the properties of structural superlubricity micro/nano-components on the surface of silicon, which is known to be the most mainstream base material for MEMS. In this paper, the electronic properties and the atomic-scale friction of the silicon-based surface structural superlubricity micro/nano-components are simulated using first-principles calculations based on the Density functional theory (DFT). By analyzing the silicon-based surface structural superlubricity micro/nano-component with adhesion performances and superlubricity characteristics. The calculation shows that the binding energy value of its lower graphene layer is larger than that of the upper layer during the slip process, and it is found that the friction force of the silicon-based structure can reach the range of 10−3 nN and the average friction coefficient can reach the range of 10−3 in the incommensurate state. Throughout the sliding process, electrostatic repulsion plays an important role in the tribological properties. The larger the electrostatic repulsion, the smoother the potential energy fluctuation, indicating less friction, while the analysis of the charge mechanism further justifies the conclusion.

Improvement and compensation of temperature drift of scale factor of a SOI-based MEMS differential capacitive accelerometer

In recent years, the analysis and improvement of temperature characteristics of Si-based capacitive accelerometers has received considerable research attention in the field of Microelectromechanical system (MEMS) sensors. Generally, the influence of temperature on the accelerometers can be mitigated by optimizing the structural design and compensating the output signal. Herein, the output characteristics of an accelerometer designed with asymmetrically arranged combs were analyzed under various temperatures. The purpose of this paper is to improve the temperature drift of scale factor (TDSF) of MEMS capacitive accelerometer, using the asymmetric layout structure to improve the TDSF fundamentally, and the least square method to achieve temperature compensation efficiently. The variations in the TDSF were compared for the symmetric and asymmetric structures. In addition, we modeled the accelerometer with an asymmetric structure for simulations to analyze the errors resulting from the electrostatic torsion phenomenon induced by the asymmetric structure. Moreover, a temperature compensation model was developed for the scale factor of the accelerometer, which was validated and verified with the data obtained from simulations and experiment. Furthermore, an accelerometer based on silicon on insulator was fabricated and tested to verify the simulation results and the compensation effects. According to the results, the scale factor of the studied accelerometer was 171.83 mV g−1 and the average value of the TDSF was 83.56 ppm °C−1 Overall, the experimental results were almost consistent with the simulation results. Under the asymmetric layout, the scale-factor stability improvement of the accelerometer could reach up to 86.96%, and the error caused by electrostatic torsion was ∼2.93%, which is relatively negligible. After compensation, the range and standard deviation of the scale factor of the accelerometer with respect to temperature were reduced by 94.46% and 95.69%, respectively, and the average value of TDSF was reduced by 95.90%, which verified the effectiveness of the compensation model.

Micro ECDM scanning process with feedback control of flexible contact force

Quartz glass has been widely used in frontier fields of MEMS (micro electro-mechanical systems) and sensors due to its excellent chemical and mechanical properties. Although ECDM (electrochemical discharge machining) is a non-traditional material removal process suitable for machining electrically non-conductive materials of high temperature resistance and hard brittleness, the adopted feeding strategy of tool electrode directly affects the machining results, especially in a micro ECDM scanning process. The existing feed methods still cannot maintain a suitable machining gap with a minimum given contact force during the micro ECDM scanning process, causing inconsistent gap state and the damage to machining stability and geometric accuracy of micro structures. In this research, a novel spindle combining a flexure hinge and a high-resolution micro-force sensor is designed, achieving the function of real-time servo control of a given micro contact force. Using the micro tool electrodes (<Φ200 μm) fabricated by the combined process of reverse-copying micro EDM and TF-WEDG (tangential feed-wire electrode discharge grinding), the circular structures are successfully machined on quartz glass with the optimized parameters of open-circuit voltage, scanning speed, and number of scanning. To guarantee the consistent depth along a scanning layer, a feed strategy of quantified depth with servo control of flexible micro force (SCFMF-QDFS) is proposed, and micro 3D structures of S-shape and square are machined with controllable accuracy of ±2 μm and ±4 μm in depth and width.

A review of piezoelectric energy harvesters for harvesting wind energy

Microelectromechanical systems (MEMS) powered by conventional batteries are disadvantaged in terms of scope of application and environmental friendliness because their power sources need to be replaced regularly and have the risk of polluting the environment. Piezoelectric technology provides a solution for harvesting clean energy such as wind energy from the environment, achieving self-supply of electrical energy for MEMS, and meeting the requirement of without management and maintenance after installation. An overview of piezoelectric wind energy harvesting can help to connect the MEMS field and meet its self-supply needs. This paper presents a comprehensive review of state-of-the-art advances in piezoelectric wind energy harvesters (PWEH). The classification of piezoelectric materials is briefly introduced. The principle of its operation is introduced. It is divided into five categories by structure: bluff body, airfoil, flag, wind concentrator, and wind turbine structures. The research status of harvester has been discussed from four perspectives: structure, application, theoretical modeling, and signal processing. The existing literature is integrated, and the future development directions in three aspects: expanding application area, improving adaptive capabilities, and application-oriented system design are proposed. This paper provides references for people in the industry who are committed to structural innovation and performance enhancement.

Copolymerization of Parylene C and Parylene F to Enhance Adhesion and Thermal Stability without Coating Performance Degradation.

Parylene C has been widely used in the fields of microelectromechanical systems (MEMS) and electronic device encapsulation because of its unique properties, such as biocompatibility and conformal coverage. However, its poor adhesion and low thermal stability limit its use in a wider range of applications. This study proposes a novel method for improving the thermal stability and enhancing the adhesion between Parylene and Si by copolymerizing Parylene C with Parylene F. The successful preparation of Parylene copolymer films containing different ratios of Parylene C and Parylene F was confirmed using Fourier-transform infrared spectroscopy and surface energy calculations. The proposed method resulted in the copolymer film having an adhesion 10.4 times stronger than that of the Parylene C homopolymer film. Furthermore, the friction coefficients and cell culture capability of the Parylene copolymer films were tested. The results indicated no degradation compared with the Parylene C homopolymer film. This copolymerization method significantly expands the applications of Parylene materials.

Experimental investigation of rotating nodal line of MEMS-based nonlinear multi-mode resonators.

Nonlinear phenomenon is presently attracting considerable attention in the field of microelectromechanical systems (MEMS). By adjusting a controllable tuning voltage, the nonlinearity of microdevices, especially on microactuators, can be precisely manipulated. To trap and separate small particles, generating a large and stable rotation force is critical in micromanipulations. Here, we report a simple and potential angular momentum cell comprising a piezoelectric MEMS-based nonlinear multi-mode resonator with integrated electrodes. A nonlinear rotating nodal line has been observed in specific frequency bands by applying a controllable low voltage of sub 5V on a 4-port resonator made of lead zirconate titanate (PZT) thin films. The magnitude of the actuated voltage is Complementary-Metal-Oxide-Semiconductor (CMOS)-compatible and easy to integrate with the circuit. Furthermore, the real-time rotation motion of the MEMS-based nonlinear multi-mode resonator is also verified by a laser doppler vibrometer (LDV) at both chirp and single input frequencies, respectively. Therefore, this angular momentum cell shows great potential in the application of micromanipulation.

Optimized chemical mechanical polishing of Parylene C for high-density wiring in flexible electronics

With the rapid development of flexible electronics, an increasing number of microfabrication strategies originating from the Si-based integrated circuits field have been explored on organic materials. Parylene C, a polymer, has been widely used in the microelectromechanical systems field because of its outstanding fabrication merits, such as room-temperature processability, conformal coating, and precise thin film deposition capability with the thickness tunable from 1 nm to 100 μm. As a good dielectric material, the Parylene C is also suitable for interlayer dielectrics in flexible electronics. This study develops an optimized chemical mechanical polishing (CMP) technique of Parylene C for high-density redistribution wiring in high-performance flexible electronics. The roughness of the Parylene C surface after CMP was as low as 14.3 ± 1.5 Å. The problems of slurry pollution and mechanical failure of the Parylene film that degrade the dielectric performance of the Parylene C could be avoided by taking the optimized CMP method. The multi-material structure constructed by Parylene C, Silicon and electroplated Copper was prepared and polished using the optimized CMP process. Additionally, a flexible wiring sample has been successfully patterned by the Damascene process through the optimized CMP process. In this sample, both the distance between each wire and the wire width were as small as 5 μm. The optimized Parylene C CMP process is easy-to-realize, highly efficient, low cost, and with minor defects; it provides a promising way to achieve high-density interconnection in high-performance flexible electronic devices.

Burr removal from high-aspect-ratio micro-pillars using ultrasonic-assisted abrasive micro-deburring

The demand for high-aspect-ratio microstructures is ever increasing in the fields of microelectromechanical systems, biomedicine, aerospace, telecommunication, and heat transfer. Mechanical micromachining processes have a distinct advantage over lithography-based processes for machining complex three-dimensional microstructures on a variety of materials with high accuracy and surface finish. But the tool-based micromachining operations face inherent issues in the form of excessive burr formation, which needs to be addressed by post-machining burr removal operations. In this study, an ultrasonic-assisted abrasive micro-deburring process employing a probe sonotrode and abrasive particles has been investigated for deburring high-aspect-ratio micro-pillars machined on aluminium 6061 and copper. Deburring of micromilled pillars of aspect ratio 5:1 has been achieved while maintaining pillar integrity. The mechanism of deburring has been observed to be mainly by the impact of the abrasive particles with a minor role played by liquid cavitation. Burr reduction as high as 88.75% for Al 6061 and 90.1% for copper has been achieved in a short processing time of 10 s. This is a significantly faster process than other ultrasonic cavitation-based deburring processes described in literature (deburring time ranging from 60 min to a few hours). With proper control of the process parameters like stand-off distance and power, burr removal has been achieved while maintaining the integrity of the micro-pillars. Pure water cavitation has also been studied for comparison, which has resulted in a burr removal by 51.5% and 53.1% for Al 6061 and copper, respectively. Upon proper selection of the process parameters, this process can be a viable alternative to existing deburring methods in terms of minimal processing time and structure damage.

Bulk metallic glass cantilever beams: Outstanding at large-deflection deformation and their application in complaint mechanisms

Excellent combination of mechanical properties of bulk metallic glasses (BMGs) are a class of relatively young and promising candidate materials for compliant mechanisms (CMs), which are usually associated with the nonlinear large-deflection deformation. In this study, an effective design strategy was proposed to enhance the flexibility of BMG cantilever beam quantitatively, which by means of increasing the ratio of loading distance to beam thickness. Moreover, the accuracy of modulus of elasticity in bending, Eb, which measured by cantilever bending test was affected seriously by the support compliance of the fixed end, and the accurate Eb value of BMG beam can be attained after eliminating this influencing factor. The critical boundary condition of cantilever beams within the scope of small-deflection deformation was identified, which situates at non-dimensional deflection parameter, δy/L, is 0.2. Correspondingly, the critical loading distance-to-thickness ratios, (L/t)c, of cantilever beams within small-deflection deformation were derived for BMGs and conventional crystalline metals, which provide a criterion to predict the potential to achieving large-deflection deformation. It is noticed that by plotting the flexural stress-δy/L relations for BMG and several conventional crystalline metals used in CMs, the unique advantages of BMG cantilever beam in the aspect of achieving large-deflection deformation and enduring higher flexural stress can be reflected more intuitively. These advantages of BMG cantilever beam are well suitable for CMs which designed to have a small footprint and requirement of large-deflection motions, such as in the fields of microelectromechanical systems (MEMS) and biomedicines.

Direct laser writing of liquid crystal elastomers oriented by a horizontal electric field.

Background: The ability to fabricate components capable of performing actuation in a reliable and controlled manner is one of the main research topics in the field of microelectromechanical systems (MEMS). However, the development of these technologies can be limited in many cases by 2D lithographic techniques employed in the fabrication process. Direct Laser Writing (DLW), a 3D microprinting technique based on two-photon polymerization, can offer novel solutions to prepare, both rapidly and reliably, 3D nano- and microstructures of arbitrary complexity. In addition, the use of functional materials in the printing process can result in the fabrication of smart and responsive devices. Methods: In this study, we present a novel methodology for the printing of 3D actuating microelements comprising Liquid Crystal Elastomers (LCEs) obtained by DLW. The alignment of the mesogens was performed using a static electric field (1.7 V/µm) generated by indium-tin oxide (ITO) electrodes patterned directly on the printing substrates. Results: When exposed to a temperature higher than 50°C, the printed microstructures actuated rapidly and reversibly of about 8% in the direction perpendicular to the director. Conclusions: A novel methodology was developed that allows the printing of directional actuators comprising LCEs via DLW. To impart the necessary alignment of the mesogens, a static electric field was applied before the printing process by making use of flat ITO electrodes present on the printing substrates. The resulting microelements showed a reversible change in shape when heated higher than 50°C.

Direct laser writing of liquid crystal elastomers oriented by a horizontal electric field

Background: The ability to fabricate components capable of performing actuation in a reliable and controlled manner is one of the main research topics in the field of microelectromechanical systems (MEMS). However, the development of these technologies can be limited in many cases by 2D lithographic techniques employed in the fabrication process. Direct Laser Writing (DLW), a 3D microprinting technique based on two-photon polymerization, can offer novel solutions to prepare, both rapidly and reliably, 3D nano- and microstructures of arbitrary complexity. In addition, the use of functional materials in the printing process can result in the fabrication of smart and responsive devices. Methods: In this study, we present a novel methodology for the printing of 3D actuating microelements comprising Liquid Crystal Elastomers (LCEs) obtained by DLW. The alignment of the mesogens was performed using a static electric field (1.7 V/µm) generated by indium-tin oxide (ITO) electrodes patterned directly on the printing substrates. Results: When exposed to a temperature higher than 50°C, the printed microstructures actuated rapidly and reversibly of about 8% in the direction perpendicular to the director. Conclusions: A novel methodology was developed that allows the printing of directional actuators comprising LCEs via DLW. To impart the necessary alignment of the mesogens, a static electric field was applied before the printing process by making use of flat ITO electrodes present on the printing substrates. The resulting microelements showed a reversible change in shape when heated higher than 50 °C.

High-quality welding of glass by a femtosecond laser assisted with silver nanofilm

Glass products with high joint strength are highly demanded in the field of microelectromechanical system (MEMS). While the quality requirement of MEMS is getting higher and higher, much attention has been paid to further improving the welding strength of the glass. Herein, a femtosecond laser welding method assisted by silver nanofilm for quartz glass is proposed. To optimize the welding results, the influence of the laser power on the location of the heat-affected zone is studied. The effect of coated silver nanofilm at the interface of two glass substrates on femtosecond laser absorptivity is conducted. Also, the welding spot size under different irradiation periods is investigated. In addition, the welding strength with and without the silver nanofilm is measured and compared. It is demonstrated that the welding strength was increased nearly 20% on average by our proposed method compared with direct femtosecond laser welding. In addition, even at the lower laser power than the welding threshold, the welding process could be realized by the proposed method.

Simulation of a Cantilever Biosensor for various Diseases Detection

Development in the field of Microelectromechanical systems has led to the enormous increase in the field of biomedical applications. In this paper, various diseases are simulated in the cantilever biosensor to detect at an early stage. The designs are modelled and simulated using Comsol multiphysics software to get the displacement value. Displacement refers to the changes in the structure by providing force or pressure on the surface of the cantilever. By the displacement value we can identify the type of disease through this biosensor.

Piezoelectric Energy Harvesting Methodologies using Ambient Mechanical Vibration: Design Perspective and Challenges

Background and Objective: Piezoelectric energy harvesting is an emergent research area for unobtrusive power supply for fully autonomous micro-scale devices. Method: The method of energy harvesting is to utilize waste ambient mechanical vibrations to generate electrical energy through the piezoelectric effect. Results and Conclusion: The present work highlights the major advances made in the field of micro- electromechanical systems based on piezoelectric energy harvester on extracting ambient vibrations and converting them into usable electric power. The present study explores energy harvesting approaches for portable electronics and self-powered wireless network nodes. The performance matrices like device physics, volume, operating frequencies, design and materials have been thoroughly analyzed in this work. Conventional cantilever fabrication steps have also been discussed. Finally, guidelines for future research and performance enhancements in the field of Piezoelectric Energy Harvesting (PEH) at micro scale have been discussed.

Topological microelectromechanical systems

We explore the topological aspect of dynamics in a micro-electro-mechanical system (MEMS), which is a combination of an electric-circuit system and a mass-spring system. A simplest example is a sequential chain of capacitors and springs. It is shown that such a chain exhibits novel topological dynamics with respect to its oscillation modes. On one hand, when it undergoes free oscillation, the system is governed by the Su-Schrieffer-Heeger model, and the topological charge is given by a winding number. Topological and trivial phases are differentiated by measuring the dynamics of the outermost plate. On the other hand, when it undergoes periodical motion in time, the system is governed by an inversion-symmetric-trimer model, and the topological phases are characterized by an inversion-symmetry indicator. There emerge topological edge states, which are well signaled by measuring electromechanical-impedance resonance. Our results will open an attractive field of topological MEMS.