This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of tho...This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of those strategies on the fabricated silicon force-balance MEMS accelerometer. The mathematical model presented is implemented in VHDL- AMS and SIMULINK TM,respectively. The simulation results from the two approaches are compared and show a slight difference. Using VHDL-AMS is flexible,reusable,and more accurate. But there is not a mature solver developed for the language and this approach takes more time, while the simulation model can be easily built and quickly evaluated using SIMULINK.展开更多
The microscopic mechanical characteristics of ultranano-crystalline diamond films which were prepared in four different atmospheres were investigated for the applications in microelectron-mechanical system（MEMS）.The...The microscopic mechanical characteristics of ultranano-crystalline diamond films which were prepared in four different atmospheres were investigated for the applications in microelectron-mechanical system（MEMS）.The loading-unloading curves and the change of modulus and hardness of samples along with depth were achieved through nanoindenter.The results show that the films which are made in atmosphere without Ar have the highest recovery of elasticity,hardness（72.9 GPa） and elastic modulus（693.7 GPa） among the samples.Meanwhile,samples fabricated at a low Ar content have higher hardness and modulus.All the results above demonstrate that atmosphere without Ar or low Ar content leads to better mechanical properties of nanodiamond films that are the candidates for applications in MEMS.展开更多
The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing t...The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing to give life, so to speak, to the small chip with a brain： One needed to awaken its senses and develop its muscles! This challenge was solved through MEMS （micro electro mechanical systems）. Indeed, MEMS today are equipped with the sense of sight, smell, hearing, taste and touch through microsensors. They are also capable of physical exertion through small muscles called microactuators. These new capabilities open wide fields of imagination and important specific applications.展开更多
This paper shows an analysis ofMEM S （micro electro mechanical systems） due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity a...This paper shows an analysis ofMEM S （micro electro mechanical systems） due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam and stationary plate, the pull-in instability happens.展开更多
The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such...The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such as accelerometers and gyros,for handheld electronics application.In parallel,MEMS has also advanced into micro total analysis system(TAS) and/or lab-on-a-chip applications.This article would discuss a relatively new but promising future direction towards MEMS biomedical implants.Specifically,Parylene C has been explored to be used as a good MEMS implant material and will be discussed in detail.Demonstrated implant devices,such as retinal and spinal cord implants,are presented in this article.展开更多
Advanced flow measurement and active flow control need the development of new type devices and systems.Micro-electro-mechanical systems(MEMS) technologies become the important and feasible approach for micro transduce...Advanced flow measurement and active flow control need the development of new type devices and systems.Micro-electro-mechanical systems(MEMS) technologies become the important and feasible approach for micro transducers fabrication.This paper introduces research works of MEMS/NEMS Lab in flow measurement sensors and active flow control actuators.Micro sensors include the flexible thermal sensor array,capacitive shear stress sensor and high sensitivity pressure sensor.Micro actuators are the balloon actuator and synthetic jet actuator respectively.Through wind tunnel test,these micro transducers achieve the goals of shear stress and pressure distribution measurement,boundary layer separation control,lift enhancement,etc.And unmanned aerial vehicle(UAV) flight test verifies the ability of maneuver control of micro actuator.In the future work,micro sensor and actuator can be combined into a closed-loop control system to construct aerodynamic smart skin system for aircraft.展开更多
Nowadays, electronic devices are more and more integrated into everyday life. These seamless integrations focus on mobility, but at the same time strive to be unobtrusive to the end user. With the introduction of pers...Nowadays, electronic devices are more and more integrated into everyday life. These seamless integrations focus on mobility, but at the same time strive to be unobtrusive to the end user. With the introduction of personal data assistants and intelligent cellular phones for the searching of the website, true mobile computing is closer than ever. However, battery technology, which powers most of these mobile connectivity solutions, has not kept up the same pace of improvement. The paper describes a methodology for the design and performance of a self-excited permanent-magnet generator applied to low power supplies. It combines an analytical field model, a lumped reluctance equivalent magnetic circuit, and an equivalent electrical circuit. An illustrated example of a 15-mW, 290-r/min generator is given, and the analysis techniques are validated by measurements on a prototype system.展开更多
文摘This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of those strategies on the fabricated silicon force-balance MEMS accelerometer. The mathematical model presented is implemented in VHDL- AMS and SIMULINK TM,respectively. The simulation results from the two approaches are compared and show a slight difference. Using VHDL-AMS is flexible,reusable,and more accurate. But there is not a mature solver developed for the language and this approach takes more time, while the simulation model can be easily built and quickly evaluated using SIMULINK.
基金Projects(51301211,21271188)supported by the National Natural Science Foundation of ChinaProject(2010A0302013)supported by the Foundation of China Academy of Engineering Physics+3 种基金Project(ZZ13005)supported by the Foundation of Laboratory of Ultra Precision Manufacturing Technology of China Academy of Engineering PhysicsProject(2012M521541)supported by the China Postdoctoral Science FoundationProject(20110933K)supported by the State Key Laboratory of Powder Metallurgy,ChinaProject(CSU2013016)support by and the Open-End Fund for Valuable and Precision instruments of Central South University,China
文摘The microscopic mechanical characteristics of ultranano-crystalline diamond films which were prepared in four different atmospheres were investigated for the applications in microelectron-mechanical system（MEMS）.The loading-unloading curves and the change of modulus and hardness of samples along with depth were achieved through nanoindenter.The results show that the films which are made in atmosphere without Ar have the highest recovery of elasticity,hardness（72.9 GPa） and elastic modulus（693.7 GPa） among the samples.Meanwhile,samples fabricated at a low Ar content have higher hardness and modulus.All the results above demonstrate that atmosphere without Ar or low Ar content leads to better mechanical properties of nanodiamond films that are the candidates for applications in MEMS.
文摘The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing to give life, so to speak, to the small chip with a brain： One needed to awaken its senses and develop its muscles! This challenge was solved through MEMS （micro electro mechanical systems）. Indeed, MEMS today are equipped with the sense of sight, smell, hearing, taste and touch through microsensors. They are also capable of physical exertion through small muscles called microactuators. These new capabilities open wide fields of imagination and important specific applications.
文摘This paper shows an analysis ofMEM S （micro electro mechanical systems） due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam and stationary plate, the pull-in instability happens.
文摘The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such as accelerometers and gyros,for handheld electronics application.In parallel,MEMS has also advanced into micro total analysis system(TAS) and/or lab-on-a-chip applications.This article would discuss a relatively new but promising future direction towards MEMS biomedical implants.Specifically,Parylene C has been explored to be used as a good MEMS implant material and will be discussed in detail.Demonstrated implant devices,such as retinal and spinal cord implants,are presented in this article.
基金National Natural Science Foundation of China (No. 90305017No. 50775188No. 51105317)
文摘Advanced flow measurement and active flow control need the development of new type devices and systems.Micro-electro-mechanical systems(MEMS) technologies become the important and feasible approach for micro transducers fabrication.This paper introduces research works of MEMS/NEMS Lab in flow measurement sensors and active flow control actuators.Micro sensors include the flexible thermal sensor array,capacitive shear stress sensor and high sensitivity pressure sensor.Micro actuators are the balloon actuator and synthetic jet actuator respectively.Through wind tunnel test,these micro transducers achieve the goals of shear stress and pressure distribution measurement,boundary layer separation control,lift enhancement,etc.And unmanned aerial vehicle(UAV) flight test verifies the ability of maneuver control of micro actuator.In the future work,micro sensor and actuator can be combined into a closed-loop control system to construct aerodynamic smart skin system for aircraft.
文摘Nowadays, electronic devices are more and more integrated into everyday life. These seamless integrations focus on mobility, but at the same time strive to be unobtrusive to the end user. With the introduction of personal data assistants and intelligent cellular phones for the searching of the website, true mobile computing is closer than ever. However, battery technology, which powers most of these mobile connectivity solutions, has not kept up the same pace of improvement. The paper describes a methodology for the design and performance of a self-excited permanent-magnet generator applied to low power supplies. It combines an analytical field model, a lumped reluctance equivalent magnetic circuit, and an equivalent electrical circuit. An illustrated example of a 15-mW, 290-r/min generator is given, and the analysis techniques are validated by measurements on a prototype system.
