Piston Motion Performance Analysis of a 3DOF Electrothermal MEMS Scanner for Medical Applications

MEMS scanners are useful for medical applications as optical coherence tomography and laser microsurgery. Although widespread design of MEMS scanners have been presented, their behavior is not well known, and thus, their motions are not easily and efficiently controlled. This deficiency induces several difficulties (limited resolution, accuracy, cycle time, etc.), and to tackle this problem, this article presents the modeling of an ISC electrothermally actuated MEMS mirror and the experimental characterization for the piston motion. Modeling and characterization are important to implement the control. A multiphysic model is proposed, and an experimental validation is performed with a good correspondence for a voltage range from 0 V to 3.5 V with a maximum displacement up to 200 µm and with a relative tilting difference of 0.1°. The article also presents a simple and efficient experimental setup to measure a displacement in dynamic and static mode, or a mirror plane tilting in static mode.     

Transmission and reflection dual operational mode MEMS display device

A novel MEMS display device comprising a light separator and MEMS light shutters is introduced. This device is operable both in transmissive mode using internal light source and in reflective mode using external sun light. In transmissive mode, the light separator directs internal backlight illuminated on its incident surface into a plural of small openings (grooves) on the viewing surface. The MEMS light shutters are used to control the color and intensity of light at individual pixels. Internal light utilization efficiency of this display is the greatest compared to any other transmissive displays. The device is capable of having true black background, hence a very high contrast ratio. In reflective mode, MEMS shutters direct part of the sun light for image display. MEMS shutters have fast response time, making the new device suitable for vivid motion picture display, and operable at very low voltages, suitable for mobile device applications.     

Development of a micro optical diffusion sensor using laser‐induced dielectrophoretic manipulation

We have developed a novel micro optical diffusion sensor (MODS) based on laser‐induced dielectrophoresis (LIDEP), which enables rapid measurement with a small sample volume and on‐site sensing of protein conformation. This paper presents the measurement principle, the chip design, and the validity of the proposed method. To verify the applicability of MODS, we confirmed a sinusoidal concentration distribution of polystyrene beads in a surface‐modified microchannel generated by LIDEP force. The decay time of the diffusion of the concentration distribution agreed well with theoretical calculations, confirming the applicability of MODS as a technique for measuring the diffusion coefficient. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20303     

Mechanical Property Measurement at the Micro/Nano‐scale1

Abstract: The introduction of sensors and actuators that have features on the scale of micrometres and nanometres has created a demand for new test methods to determine the mechanical properties of the materials used in them. These devices are fabricated by processes that are used in the microelectronics industry, and test specimens must be produced by the same processes. An entirely new area of experimental solid mechanics has developed over the past 15 years to meet these needs, and this paper summarises some of the progress. The coverage is limited to uniaxial tensile and compressive tests as these are the premier and standardised tests for macrospecimens.     

Numerical modelling of impact rupture in polysilicon microsystems

A 2D geometrical model for polycrystals was developed in this paper by means of a Voronoi tessellation in which each crystal is assumed to be elastic anisotropic. An implicit–explicit FE dynamic code coupled with an automatic procedure for the introduction of cohesive interface elements with cohesive traction-jump softening laws was used in order to simulate intergranular and transgranular fracture. Accidental drop simulations were performed with the principal aim to capture the maximum acceleration and to simulate local rupture phenomena in MEMS. In order to reduce the excessive problem size, a simplified, decoupled global–local three level multi-scale approach was used.     

微执行器的研究与展望

在微机电系统中,微执行器是核心部件。为了优化设计微执行器,通过对比近年来各种微执行器的研究和发展,系统地总结了线性位移微执行器所采用的驱动原理、驱动方式和应用以及存在的优缺点等。针对热执行器,提出了个人的一些见解。     

Advances in Fabrication of TES μ-Calorimeter Arrays and Associated Filter Structures for AC-Biased Read Out

In this paper we describe microfabrication developments for a 1024 pixel calorimeter array, to be used in future X-ray spectroscopic space missions. We report on an optimization study of high packing factor, mushroom shaped, Cu/Bi absorbers, for which a sputter deposition technique into a new type of photoresist mould has been developed. We have fabricated a prototype 32×32 array where 98 representable pixels are potentially functioning TESs. To gain more control on the detector pixel performance a new procedure was developed to couple absorber and thermometer, utilizing a thin insulating layer. Advances are reported in the fabrication of superconducting LC resonating circuits, needed for frequency domain multiplexed read out. A quality factor Q∼4000 @ 2.6 MHz has been measured, which was limited by critical current in the circuit.      

MICROFABRICATION OF CYLINDRICAL ION TRAP MASS SPECTROMETER ARRAYS FOR HANDHELD CHEMICAL ANALYZERS

A new microfabrication method for micro-cylindrical ion trap (μ-CIT) mass spectrometer arrays (r_o, z_o ≅ 360 μm) is presented along with a strategy for incorporating integrated high-field emission electron sources for ionization. Simulations of the performance of μ-CITs were used to guide the geometrical design of the array, and process flows for microfabrication in silicon were developed and optimized for reduced capacitance. The microfabrication process is described in detail along with initial test results. Field emission sources were also fabricated in silicon using an edge-to-edge emission strategy to improve robustness in moderate vacuum environments. Simulations were also used to guide the design of the field emitter arrays. The microfabrication process is described and initial field emission data are presented. Strategies for further optimization and integration are also briefly discussed.     

Experimental and simulation research on the influence of voltage amplitude,frequency and carrier gas flow rate on the performance of FAIMS

A micro sensor chip of High-field Asymmetric Waveform Ion Mobility Spectrometry(FAIMS) was designed and fabricated by inductively coupled plasma(ICP) etching on the both sides of silicon and double silicon-glass bonding,with dimensions of 18.8 mm×12.4 mm×1.2mm.The sample ions were created at ambient pressure by VUV lamp ion source,which was equipped with a 10.6 eV photo discharge lamp(λ=116.5 nm).The 2-pentanone was adopted to illustrate the influences of high-field rectangular asymmetric waveform voltage a...