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The pull-down instability is a newly found phenomenon for oscillators with even nonlinearities. It is a seemingly periodic motion, which will suddenly pull down after some cycles. The phenomenon is similar to the pull-in instability in the micro-electromechanical systems. This paper restudies the well-known Toda oscillator, which is considered to be in periodic motion. Its pseudo-periodic property is studied and the pull-down instability is found for the first time ever. To this end, this paper establishes a variational principle for the Toda oscillator, and the criterion for prediction of the pull-down motion is obtained. A simple formulation to calculate the pull-down instability is proved and verified through examples. Furthermore, an approximate frequency formula is obtained by Li–He modified homotopy perturbation method. [ABSTRACT FROM AUTHOR]

Ethanol sensors have found extensive applications across various industries, including the chemical, environmental, transportation, and healthcare sectors. With increasing demands for enhanced performance and reduced energy consumption, there is a growing need for developing new ethanol sensors. Micro-electromechanical system (MEMS) devices offer promising prospects in gas sensor applications due to their compact size, low power requirements, and seamless integration capabilities. In this study, SnO2-TiO2 nanocomposites with varying molar ratios of SnO2 and TiO2 were synthesized via ball milling and then printed on MEMS chips for ethanol sensing using electrohydrodynamic (EHD) printing. The study indicates that the two metal oxides dispersed evenly, resulting in a well-formed gas-sensitive film. The SnO2-TiO2 composite exhibits the best performance at a molar ratio of 1:1, with a response value of 25.6 to 50 ppm ethanol at 288 °C. This value is 7.2 times and 1.8 times higher than that of single SnO2 and TiO2 gas sensors, respectively. The enhanced gas sensitivity can be attributed to the increased surface reactive oxygen species and optimized material resistance resulting from the chemical and electronic effects of the composite. [ABSTRACT FROM AUTHOR]

This study focuses on obtaining differences in rock fracture surface morphology under various loading directions and speeds to infer rock damage mechanics by using micro-electro–mechanical system (MEMS) sensors, which can measure stress, strain, and displacement during loading accurately, providing detailed data for understanding the rock fracture mechanism for physics-informed statistics. Statistical variables analyze directional angle samples of the normal vector central line. The deviation normal distribution coefficient (DNDC) for rock fracture surface normal vectors is defined by the kurtosis coefficient. Brazilian splitting tests calculate the DNDC for Brazilian disk fracture surfaces. The variation in the DNDC with a measurement scale distinguishes morphological differences. Three results are obtained: the DNDC has a scale effect; loading the specimen in another direction before compression causes internal damage; and different loading speeds do not significantly change the DNDC. This research holds promise for a better understanding of rock fractures.

Ethanol sensors have found extensive applications across various industries, including the chemical, environmental, transportation, and healthcare sectors. With increasing demands for enhanced performance and reduced energy consumption, there is a growing need for developing new ethanol sensors. Micro-electromechanical system (MEMS) devices offer promising prospects in gas sensor applications due to their compact size, low power requirements, and seamless integration capabilities. In this study, SnO2-TiO2 nanocomposites with varying molar ratios of SnO2 and TiO2 were synthesized via ball milling and then printed on MEMS chips for ethanol sensing using electrohydrodynamic (EHD) printing. The study indicates that the two metal oxides dispersed evenly, resulting in a well-formed gas-sensitive film. The SnO2-TiO2 composite exhibits the best performance at a molar ratio of 1:1, with a response value of 25.6 to 50 ppm ethanol at 288 °C. This value is 7.2 times and 1.8 times higher than that of single SnO2 and TiO2 gas sensors, respectively. The enhanced gas sensitivity can be attributed to the increased surface reactive oxygen species and optimized material resistance resulting from the chemical and electronic effects of the composite.

Bedrock wear is statistically one of the major causes of submarine cable failure. Therefore， a new submarine cable monitoring system is developed. First， a long-distance multi-node synchronous acquisition method is proposed to establish a shape reconstruction and positioning model of the submarine cable. Then， sensors， acquisition boards， control boards， 4G wireless transmission and battery modules are developed， and a submarine cable monitoring system based on the MEMS （micro-electromechanical systems） sensor array is built. Finally， high-intensity magnetic environment test， pressure test， accuracy test of the sensor array， and long-term monitoring of submarine cables in the landing section in Zhujiajian prove that the system can monitor displacement of submarine cables and remotely transmit the monitoring data in real time.

The dynamic pull-in instability of a microstructure is a vast research field and its analysis is of great significance for ensuring the effective operation and reliability of micro-electromechanical systems (MEMS). A fractal modification for the traditional MEMS system is suggested to be closer to the real state as a practical application in the air with impurities or humidity. In this paper, we establish a fractal model for a class of electrostatically driven microstructure resonant sensors and find the phenomenon of pull-in instability caused by DC bias voltage and AC excitation voltage. The variational iteration method has been extended to obtain approximate analytical solutions and the pull-in threshold value for the fractal MEMS system. The result obtained from this method shows good agreement with the numerical solution. The simple and efficient operability is demonstrated through theoretical analysis and results comparisons. [ABSTRACT FROM AUTHOR]

A nonlinear vibration system, over a span of convincing periodic motion, might break out abruptly a catastrophic instability, but the lack of a theoretical tool has obscured the prediction of the outbreak. This paper deploys the amplitude-frequency formulation for nonlinear oscillators to reveal the critically important mechanism of the pseudo-periodic motion, and finds the quadratic nonlinear force contributes to the pull-down phenomenon in each cycle of the periodic motion, when the force reaches a threshold value, the pull-down instability occurs. A criterion for prediction of the pull-down instability is proposed and verified numerically. [ABSTRACT FROM AUTHOR]

Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The pull-in behavior is an inherent property of the micro-electromechanical oscillator. The bisection method and an iterative method are introduced to find its pull-in voltage, and the main factors affecting the pull-in voltage are elucidated. The simple and efficient operability is demonstrated through theoretical analysis and result comparison. [ABSTRACT FROM AUTHOR]

Typically, an inertial navigation system (INS) is used to determine the position, speed, and orientation of an object moving relative to the earth's surface. The navigation information (position, speed and orientation) of an unmanned aerial vehicle (UAV) is needed to control its flight. Since the resistance of INS to interferences is very high, it is possible to ensure reliable flights in conditions of high-intensity noise. This article explores the principles of constructing inertial measurement units (IMU) that are part of the INS and indicates perspective directions for their development. Micro-electromechanical inertial measurement units were studied in this work, and functional and principal electrical circuits for connecting units of inertial measurements to the microcontroller were developed. The results of practical measurements of units without calibration and after calibration were obtained using the created laboratory device. Based on the obtained results, the necessity of sensor calibration was revealed, and accuracy was improved by performing calibration with the Kalman filter algorithm. The Kalman filter is the heart of the navigation system. In a low-cost system, IMU errors like bias, scale factor error and random walk noise dominate the INS error growth.

Aluminum scandium nitride (Al1−xScxN) film has drawn considerable attention owing to its enhanced piezoelectric response for micro-electromechanical system (MEMS) applications. Understanding the fundamentals of piezoelectricity would require a precise characterization of the piezoelectric coefficient, which is also crucial for MEMS device design. In this study, we proposed an in situ method based on a synchrotron X-ray diffraction (XRD) system to characterize the longitudinal piezoelectric constant d33 of Al1−xScxN film. The measurement results quantitatively demonstrated the piezoelectric effect of Al1−xScxN films by lattice spacing variation upon applied external voltage. The as-extracted d33 had a reasonable accuracy compared with the conventional high over-tone bulk acoustic resonators (HBAR) devices and Berlincourt methods. It was also found that the substrate clamping effect, leading to underestimation of d33 from in situ synchrotron XRD measurement while overestimation using Berlincourt method, should be thoroughly corrected in the data extraction process. The d33 of AlN and Al0.9Sc0.1N obtained by synchronous XRD method were 4.76 pC/N and 7.79 pC/N, respectively, matching well with traditional HBAR and Berlincourt methods. Our findings prove the in situ synchrotron XRD measurement as an effective method for precise piezoelectric coefficient d33 characterization. [ABSTRACT FROM AUTHOR]

Currently, vestibular rehabilitation approaches used to monitor body position and movement during rehabilitation training require specialized equipment or rely on clinician observation. Thus, a simpler position-sensing approach that can be used to monitor movement during vestibular rehabilitation is required. This study used wearable motion sensors with built-in accelerometers and gyrometers to assess movement in adults. We explored stepping patterns in adults using this motion-sensing system. Six healthy adults (men, age 27.3 ± 5.8 years) underwent a modified Fukuda stepping test (Foulage test [FT]) while wearing a six-axis motion sensor (accelerometer: X-axis, Y-axis, Z-axis; gyrometer: X-axis, Y-axis, Z-axis) positioned at the head, thorax, and lumbar spine. For motion sensor parameters, we calculated the root mean square (RMS), autocorrelation coefficient (AC), power spectrum (PS) of the AC, and Euler angles from the six-axis motion sensor. For the FT parameters, the FT value, step variance, and θ values were calculated. Data were analyzed, and multivariable regression analysis was performed using the FT value, step variance, and θ value as the dependent variables to investigate their influence on dynamic equilibrium. The explanatory variables included the motion sensor parameters, RMS, AC, and PS. Our results suggested that almost no head and lumbar spine movement occurred while stepping with eyes open. Contrastingly, the head and lumbar spine swayed with eyes closed. This accelerometric and gyroscopic device is easy to use, does not require specialized equipment, and can be used to analyze performance in the modified Fukuda stepping test in clinical practice. Inertial sensors have many advantages over other sensing technologies.

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary. Typically, an inertial navigation system (INS) is used to determine the position, speed, and orientation of an object moving relative to the earth's surface. The navigation information (position, speed and orientation) of an unmanned aerial vehicle (UAV) is needed to control its flight. Since the resistance of INS to interferences is very high, it is possible to ensure reliable flights in conditions of high-intensity noise. This article explores the principles of constructing inertial measurement units (IMU) that are part of the INS and indicates perspective directions for their development. Micro-electromechanical inertial measurement units were studied in this work, and functional and principal electrical circuits for connecting units of inertial measurements to the microcontroller were developed. The results of practical measurements of units without calibration and after calibration were obtained using the created laboratory device. Based on the obtained results, the necessity of sensor calibration was revealed, and accuracy was improved by performing calibration with the Kalman filter algorithm. The Kalman filter is the heart of the navigation system. In a low-cost system, IMU errors like bias, scale factor error and random walk noise dominate the INS error growth. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Light detection and ranging (LiDAR), combining traditional radar technology with modern laser technology, has much potential for applications in navigation, mapping, and so on. Benefiting from the superior performance, an all-solid-state beam steering realized by integrated optical phased array (OPA) is one of the key components in the LiDAR system. In this review, we first introduce the basic principle of OPA for beam steering. Then, we briefly review the detailed advances of different solutions such as micro-electromechanical system OPA, liquid crystal OPA, and metasurface OPA, where our main focus was on the recent progress of OPA in photonic integrated chips. Finally, we summarize the different solutions and discuss the challenges and perspectives of all-solid-state beam steering for LiDAR. [ABSTRACT FROM AUTHOR]

Aluminum scandium nitride (Al1−xScxN) film has drawn considerable attention owing to its enhanced piezoelectric response for micro-electromechanical system (MEMS) applications. Understanding the fundamentals of piezoelectricity would require a precise characterization of the piezoelectric coefficient, which is also crucial for MEMS device design. In this study, we proposed an in situ method based on a synchrotron X-ray diffraction (XRD) system to characterize the longitudinal piezoelectric constant d33 of Al1−xScxN film. The measurement results quantitatively demonstrated the piezoelectric effect of Al1−xScxN films by lattice spacing variation upon applied external voltage. The as-extracted d33 had a reasonable accuracy compared with the conventional high over-tone bulk acoustic resonators (HBAR) devices and Berlincourt methods. It was also found that the substrate clamping effect, leading to underestimation of d33 from in situ synchrotron XRD measurement while overestimation using Berlincourt method, should be thoroughly corrected in the data extraction process. The d33 of AlN and Al0.9Sc0.1N obtained by synchronous XRD method were 4.76 pC/N and 7.79 pC/N, respectively, matching well with traditional HBAR and Berlincourt methods. Our findings prove the in situ synchrotron XRD measurement as an effective method for precise piezoelectric coefficient d33 characterization.

This paper presents a new block diagram for defining a dynamic error in instruments for measuring the angular position of moving objects. The diagram proposes a new concept for investigating dynamic error characteristics as well as for compiling algorithms, inventing methods, and employing means for elimination of the dynamic error as independent component. Based on that concept, a system for measuring the roll, pitch, trim, and heel of moving objects has been developed. The system features high accuracy ensured through a combination of the capacities of different micro-electromechanical sensors that are unified into a shared platform with a specific algorithm used to determine and eliminate a real-time dynamic error. In addition, the paper presents the results from experimental research work. The results confirm the large operational capacity of the proposed concept concerning measurement accuracy. [ABSTRACT FROM AUTHOR]

Position controlling with less overshoot and control effort is a fundamental issue in the design and application of micro-actuators such as micro-positioner. Also, tracking a considered path is very crucial for some particular applications of micro-actuators such as surgeon robots. Herein, a proportional–integral–derivative controller is designed using a feedback linearization technique for path tracking control of a cantilever electromechanical micro-positioner. The micro-positioner is simulated based on a 1-degree-of-freedom lumped-parameter model. Three different paths are considered, and the capability of the designed controller on the path tracking with lower error and control effort is investigated. The obtained results demonstrate the efficiency of the designed proportional–integral–derivative controller not only for reducing the tracking error but also for decreasing the control effort. [ABSTRACT FROM AUTHOR]

Light detection and ranging (LiDAR), combining traditional radar technology with modern laser technology, has much potential for applications in navigation, mapping, and so on. Benefiting from the superior performance, an all-solid-state beam steering realized by integrated optical phased array (OPA) is one of the key components in the LiDAR system. In this review, we first introduce the basic principle of OPA for beam steering. Then, we briefly review the detailed advances of different solutions such as micro-electromechanical system OPA, liquid crystal OPA, and metasurface OPA, where our main focus was on the recent progress of OPA in photonic integrated chips. Finally, we summarize the different solutions and discuss the challenges and perspectives of all-solid-state beam steering for LiDAR.

Capacitive pressure sensors have become a reasonable choice due to their low power consumption, energy efficiency, and robustness. In this paper, a thorough investigation of MEMS based capacitive pressure sensor with square diaphragm has been carried out. A comparative study of the diaphragm displacement and capacitance as a function of external pressure and temperature has been done by using various diaphragm materials such as Si, Poly Si, Si3N4 and 3C-SiC. The performance analysis of the device was envisaged with and without packaging stress by measuring various parameters. The simulation results are emphasized on the change in capacitance at different die bonding temperatures. Temperature dependence of capacitance at varying ambient pressure has also been realized. The present work will facilitate researchers for choosing a selective material for automotive applications. [ABSTRACT FROM AUTHOR]

Systems that are capable of robustly reproducing single‐molecule junctions are an essential prerequisite for enabling the wide‐spread testing of molecular electronic properties, the eventual application of molecular electronic devices, and the development of single‐molecule based electrical and optical diagnostics. Here, a new approach is proposed for achieving a reliable single‐molecule break junction system by using a microelectromechanical system device on a chip. It is demonstrated that the platform can (i) provide subnanometer mechanical resolution over a wide temperature range (≈77–300 K), (ii) provide mechanical stability on par with scanning tunneling microscopy and mechanically controllable break junction systems, and (iii) operate in a variety of environmental conditions. Given these fundamental device performance properties, the electrical characteristics of two standard molecules (hexane‐dithiol and biphenyl‐dithiol) at the single‐molecule level, and their stability in the junction at both room and cryogenic temperatures (≈77 K) are studied. One of the possible distinctive applications of the system is demonstrated, i.e., observing real‐time Raman scattering in a single‐molecule junction. This approach may pave a way to achieving high‐throughput electrical characterization of single‐molecule devices and provide a reliable platform for the convenient characterization and practical application of single‐molecule electronic systems in the future. [ABSTRACT FROM AUTHOR]

Vibration energy harvesting typically involves a mechanical oscillatory mechanism to accumulate ambient kinetic energy, prior to the conversion to electrical energy through a transducer. The convention is to use a simple linear mass-spring-damper oscillator with its resonant frequency tuned towards that of the vibration source. In the past decade, there has been a rapid expansion in research of vibration energy harvesting into various nonlinear vibration principles such as Duffing nonlinearity, bistability, parametric oscillators, stochastic oscillators and other nonlinear mechanisms. The intended objectives for using nonlinearity include broadening of frequency bandwidth, enhancement of power amplitude and improvement in responsiveness to non-sinusoidal noisy excitations. However, nonlinear vibration energy harvesting also comes with its own challenges and some of the research pursuits have been less than fruitful. Previous reviews in the literature have either focussed on bandwidth enhancement strategies or converged on select few nonlinear mechanisms. This article reviews eight major types of nonlinear vibration energy harvesting reported over the past decade, covering underlying principles, advantages and disadvantages, and application-specific guidance for researchers and designers. [ABSTRACT FROM AUTHOR]

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fourier transform spectrometers (FTS), mostly working in infrared (IR) or near infrared (NIR) range, provide a variety of chemical or material analysis with high sensitivity and accuracy and are widely used in public safety, environmental monitoring and national border security, such as explosive detection. However, because of being bulky and expensive, they are usually used in test centers and research laboratories. Miniaturized FTS have been developed rapidly in recent years, due to the increasing demands. Using micro-electromechanical system (MEMS) micromirrors to replace the movable mirror in a conventional FTS system becomes a new realm. This paper first introduces the principles and common applications of conventional FTS, and then reviews various MEMS based FTS devices.

Monitoring blood coagulation is an important issue in the surgeries and the treatment of cardiovascular diseases. In this work, we reported a novel strategy for the blood coagulation monitoring based on a micro-electromechanical film bulk acoustic resonator. The resonator was excited by a lateral electric field and operated under the shear mode with a frequency of 1.9 GHz. According to the apparent step-ladder curves of the frequency response to the change of blood viscoelasticity, the coagulation time (prothrombin time) and the coagulation kinetics were measured with the sample consumption of only 1 μl. The procoagulant activity of thromboplastin and the anticoagulant effect of heparin on the blood coagulation process were illustrated exemplarily. The measured prothrombin times showed a good linear correlation with R 2 =0.99969 and a consistency with the coefficient of variation less than 5% compared with the commercial coagulometer. The proposed film bulk acoustic sensor, which has the advantages of small size, light weight, low cost, simple operation and little sample consumption, is a promising device for miniaturized, online and automated analytical system for routine diagnostics of hemostatic status and personal health monitoring. [ABSTRACT FROM AUTHOR]

Currently, vestibular rehabilitation approaches used to monitor body position and movement during rehabilitation training require specialized equipment or rely on clinician observation. Thus, a simpler position-sensing approach that can be used to monitor movement during vestibular rehabilitation is required. This study used wearable motion sensors with built-in accelerometers and gyrometers to assess movement in adults. We explored stepping patterns in adults using this motion-sensing system. Six healthy adults (men, age 27.3 ± 5.8 years) underwent a modified Fukuda stepping test (Foulage test [FT]) while wearing a six-axis motion sensor (accelerometer: X-axis, Y-axis, Z-axis; gyrometer: X-axis, Y-axis, Z-axis) positioned at the head, thorax, and lumbar spine. For motion sensor parameters, we calculated the root mean square (RMS), autocorrelation coefficient (AC), power spectrum (PS) of the AC, and Euler angles from the six-axis motion sensor. For the FT parameters, the FT value, step variance, and θ values were calculated. Data were analyzed, and multivariable regression analysis was performed using the FT value, step variance, and θ value as the dependent variables to investigate their influence on dynamic equilibrium. The explanatory variables included the motion sensor parameters, RMS, AC, and PS. Our results suggested that almost no head and lumbar spine movement occurred while stepping with eyes open. Contrastingly, the head and lumbar spine swayed with eyes closed. This accelerometric and gyroscopic device is easy to use, does not require specialized equipment, and can be used to analyze performance in the modified Fukuda stepping test in clinical practice. Inertial sensors have many advantages over other sensing technologies., (© 2023 The Author(s).)

There is an expanding interface between electronic engineering and neurosurgery. Rapid advances in microelectronics and materials science, driven largely by consumer demand, are inspiring and accelerating development of a new generation of diagnostic, therapeutic, and prosthetic devices for implantation in the nervous system. This paper reviews some of the basic science underpinning their development and outlines some opportunities and challenges for their use in neurosurgery. [ABSTRACT FROM AUTHOR]

The vibration analysis of a micro-pump diaphragm is presented. A piezoelectric micro-pump is studied. For this purpose, a dynamic model of the micro-pump is derived. The micro-pump diaphragm is modeled as circular double membranes, a piezoelectric one as actuator and a silicon one for representing the membrane for pumping action. The damping effect of the fluid is introduced into the equations. Vibration analysis is established by explicitly solving the dynamic model. The natural frequencies and mode shapes are calculated. The orthogonality conditions of the system are discussed. To verify the results, the finite-element micro-pump model is developed in ANSYS software package. The results show that the two methods are well comparable. [ABSTRACT FROM AUTHOR]

Abstract: Dual pulse actuation voltage waveforms that are capable of mitigating micro-electromechanical system (MEMS) switch bouncing are presented. The displacement and velocity of the MEMS switch membrane actuated using these waveforms are then simulated and compared. To eliminate bouncing, the velocity of the membrane should ideally be zero just before contact is made. Otherwise the large momentum from high velocity impact will bounce the membrane back, extending the switching time and bringing about wear and tear to the contact surfaces. The effect of MEMS switch parameter variations on the bouncing membrane is then studied for switches with different gap widths. The impact of the variation in the voltage waveform is also investigated in this paper. The exponentially saturating dual-pulse actuation waveform has shown great robustness against both switch and voltage waveform parameter variations. The waveform also exhibited the fastest switching time for a wider range of parameters variations. Practical experiments were carried out on TeraVicta TT712-68CSP MEMS switch to corroborate the findings. [Copyright &y& Elsevier]

Abstract: In this work, we present a 4-cell air-breathing micro direct methanol fuel cell (μDMFC) stack featured with novel n-inlet and n-outlet (NINO) anode flow fields. Compared with the conventional parallel flow field, the NINO flow field with micro structures improves the methanol solution transport efficiency and facilitates the exclusion of CO2 gas bubbles accumulated in flow channels. The μDMFC stack patterned with novel NINO flow field is fabricated using silicon-based micro electromechanical system (MEMS) technologies. The polydimethylsiloxane (PDMS) distributors are used not only for the stack packaging but also for the uniform distribution of methanol solution through the connected double-side patterns. Experimental results reveal that the NINO flow fields exhibit higher peak power density than that of the conventional flow field. The NINO structures with different patterns have significant influences not only on the momentum transfer but also on the cell performance. The maximum power output of the μDMFC stack can yield about 80mW at room temperature, which is significative for portable applications. [Copyright &y& Elsevier]

Abstract: These last 10 years, smaller, less expensive, and higher performance sensors are required for gas sensing applications. To date no true detection principle has been recognized as the best candidate for such application. Microsytems or Micro/Nano ElectroMechanical Systems (M/NEMS) used as gravimetric detectors are among the probable candidates. The technology can indeed be manufactured en masse and can provide multi-gas analysing platform. In this paper, we present a comprehensive overview of micro/nano sensors based on the gravimetric effect to detect an absorbed gas on top of their surfaces. The paper provides a comparison between different electromechanical devices (Bulk Acoustic Wave, Surface Acoustic Wave, Capacitive Micro-machined Ultrasonic Transducer, Micro/Nano cantilevers) with an introduction to gas adsorption mechanisms, material selection, detection principles and design guidance useful to researchers or engineers. [Copyright &y& Elsevier]

The paper presents a scheme of the biosensor for determining the intracellular pressure of erythrocytes. The possibility of measuring of the volume and area of the erythrocyte is provided in a biosensor to determine the value intracellular pressure. In MEMS this creates flow that enters into Coulter capacitive sensor through the rate control system and then in the system of signal transmitting. The definition of erythrocyte volume and calculation of intracellular pressure occur in the computer system. [ABSTRACT FROM AUTHOR]

This work presents a nonparametric identification method to study the nonlinear response of a micro-electromechanical system (MEMS) resonator. The MEMS resonator is a clamped–clamped microbeam fabricated for out-of-plane motion, which is dominated by the cubic nonlinearity due to mid-plane stretching while actuated by electrostatic forces. Experimental measurements show hardening behavior in the frequency–response of the first symmetric mode of the resonator due to the dominant cubic nonlinearity. Modeling the dynamics of the microbeam using a nonparametric identification method is shown to be very effective in capturing the characteristics of the complex nonlinear system at different electrostatic AC and DC voltages. [ABSTRACT FROM AUTHOR]

Translational research may lead to development of micro-electromechanical system-based devices to treat muscle and nerve dysfunctions whose current treatments are inadequate and, at best, palliative. This paper discusses the development of engineered microsystems as a treatment option for palsies of the seventh cranial nerve and the potential application of these devices as a platform technology for treatment of other nervous dysfunctions. The engineering techniques for electrical and chemical stimulation of denervated muscle are discussed along with current caveats from clinical and engineering standpoints. As opposed to current treatments, miniaturized implants offer the possibility of the reduced toxicity and increased specificity of direct drug delivery. As with the increased miniaturization of other technologies, engineering of these increasingly small implantable microsystems holds great promise for the future development of yet smaller, even nanoscale, implantable devices. [ABSTRACT FROM AUTHOR]

In order to understand the loss mechanism of mechanical oscillators in micro-electromechanical systems, we have studied the temperature dependence of the quality factor Q of a high Q silicon mechanical oscillator from 0.4 to 300 K. At temperatures above 70 K, the energy loss is principally caused by thermoelastic effect in the flexural components of the modes. Below 50 K, we find the improvements in vibration isolation guided by the finite element method which do not significantly improve its Q. This indicates that some intrinsic loss mechanism may still be important even at low temperatures. [Copyright &y& Elsevier]

• Influencing parameters of the flame optimization schemes are summarized. • Influence parameters of the micro-thermal photoelectric system are analyzed. • Influence parameters of the thermoelectric conversion efficiency are investigated. • Technical limitations and development of the micro power equipment are summarized. Hydrocarbon fuel and hydrogen are used as fuels for micro power equipment to replace traditional batteries and provide energy for micro-electromechanical systems, which has become a hot research direction. However, due to the reduction in the size of micro power equipment, not only the flame in the micro combustor is affected, but the overall energy conversion efficiency of micro power equipment is also affected by the size effect. Therefore, it is significance to analyze the energy loss and design optimization methods pertinently from the point of energy conversion. In the past ten years, many researchers have done research about the direction, which has been reviewed in this article. For the flame optimization, the influencing parameters of optimization methods such as exhaust gas recirculation, cavity combustor, bluff body combustor, porous media combustion, and hydrocarbon fuels mixed with hydrogen are summarized. For the micro-thermal photoelectric system, the influence parameters of combustion efficiency, radiant efficiency, spectral efficiency, view factor efficiency and photovoltaic cell efficiency are analyzed. In the micro-thermoelectric system, the influence parameters of combustion efficiency, heat conduction efficiency and thermoelectric conversion efficiency are analyzed. For the micro internal combustion engine, the influencing parameters of combustion efficiency and conversion efficiency are analyzed. Finally, the technical limitations and development of each micro power equipment are summarized in this article. [ABSTRACT FROM AUTHOR]

Single-Molecule Junctions: An On-Chip Break Junction System for Combined Single-Molecule Conductance and Raman Spectroscopies (Adv. Funct. Keywords: cryogenic characterization; electrical characterization; micro-electromechanical system; Raman spectroscopy; single-molecule junction EN cryogenic characterization electrical characterization micro-electromechanical system Raman spectroscopy single-molecule junction 1 1 1 07/11/20 20200709 NES 200709 In article number 2000615, Joshua Hihath and co-workers present a novel on-chip single-molecule break junction device utilizing a micro-electromechanical system fabricated using conventional semiconductor manufacturing processes. Cryogenic characterization, electrical characterization, micro-electromechanical system, Raman spectroscopy, single-molecule junction. [Extracted from the article]

Fourier transform spectrometers (FTS), mostly working in infrared (IR) or near infrared (NIR) range, provide a variety of chemical or material analysis with high sensitivity and accuracy and are widely used in public safety, environmental monitoring and national border security, such as explosive detection. However, because of being bulky and expensive, they are usually used in test centers and research laboratories. Miniaturized FTS have been developed rapidly in recent years, due to the increasing demands. Using micro-electromechanical system (MEMS) micromirrors to replace the movable mirror in a conventional FTS system becomes a new realm. This paper first introduces the principles and common applications of conventional FTS, and then reviews various MEMS based FTS devices. [ABSTRACT FROM AUTHOR]

In the paper we carry out the calculation mechanical properties and intracellular pressure of erythrocytes by finite element method and comparison of these data to the experimental data obtained using atomic force microscopy. The paper proposes a model of the erythrocyte representing the erythrocyte as a homogeneous elastic body with the elasticity depending on the distance to the center of the erythrocyte. The model is based on data from atomic force microscopy obtained by various authors, in particular the data on rigidity of the membrane, which depends on the position of the measuring point on the surface. The good agreement between calculated and experimental data confirms the consistency of the model and allows us to conclude that the morphology of the erythrocyte is largely determined by the elastic properties of the membrane and intercellular pressure. [ABSTRACT FROM AUTHOR]