电热激励硅谐振器件的研究

设计了悬臂梁结构电热激励、压阻拾取硅微机械谐振器件,分析了电热激励和压阻拾取的基本工作原理,设计了与Bipolar工艺兼容的器件制作工艺流程,并制作了器件样品.对真空中器件的幅频特性进行了实验研究,研究结果表明,在粗真空范围内,保持激励功率不变的情况下,微悬臂梁的振幅、谐振频率与真空度之间具有明显的依赖关系,可以用来设计、制作MEMS粗真空谐振式传感器.     

微悬臂梁FPA红外成像系统实时图像去噪算法研究

基于MEMS热传感效应的红外成像有着独特的优势。利用双材料微悬臂梁制作了MEMS IR FPA,并构建了红外成像系统。针对基于双材料微悬臂梁FPA红外成像系统中的图像噪声,提出了离散量和平均灰度的红外图像实时处理算法,解决了灰度阈值分割法在去除噪声的同时滤除掉目标物体像素、使红外图像细节丢失且灰度级减少的问题,在目标物体像素损失较小的情况下,去除了目标物体周围的随机噪声及背景噪声,提高了信噪比。     

压电微悬臂梁共振频率的检测系统

介绍了一种压电微悬臂梁共振频率检测系统.压电材料沉积在微悬臂梁上,在压电层的上下电极之间施加交变电压使其振动,当微悬臂梁的振动频率等于它的固有频率时,发生共振,此时微悬臂梁的振幅最大.结合所设计的激励电路以及微悬臂梁共振频率检测电路,对压电微悬臂梁进行了检测实验.实验结果表明,放大电路能够检测出压电微臂梁的共振频率,并且压电微悬臂梁达到共振时,共振频率附近振幅远大于其他频率对应的振幅,振幅最大值接近600 nm.     

单轴应力下热氧化SiO_2的介电电致伸缩系数研究

微机电系统和集成电路中常用的热氧化SiO2是各向同性材料,研究了其在单轴应力场中介电常数的变化规律。依据介质在自由和束缚两种边界条件下受到单轴应力作用产生的应变不同,从电动力学基本关系出发推导了各向同性电介质两种边界下的介电电致伸缩系数计算公式,表明介电电致伸缩系数是与电介质的初始介电常数、杨氏模量和泊松比有关的常数。计算得到热氧化SiO2薄膜在自由和束缚条件下的介电电致伸缩系数M12分别为-0.143×10-21和-0.269×10-21 m2/V2。搭建了基于三维微动台的微位移加载系统,测量了在单轴应力下微悬臂梁SiO2薄膜电容的变化,测量得到热氧化SiO2薄膜的M12为(-0.19±0.01)×10-21 m2/V2,表明实际SiO2薄膜介质层的边界条件处于自由和束缚之间。     

Temperature dependence of the photothermal laser coolina efficiency for a micro-cantilever

The relationship between the photothermal cooling efficiency of a micro-cantilever＇s mechanical mode and the en- vironmental temperature is studied. The micro-cantilever and a polished fiber end form a low finesse Fabry-Perot （FP） cavity. Experimental results in a temperature range from 77 K to 298 K show that temperature has an obvious influence on photothermal cooling efficiency. The photothermal cooling efficiency, ηph, at 100 K is 10 times that at 298 K. This accords well with the theoretical analysis that the high photothermal cooling efficiency can be achieved when photothermal response time, τph, and mechanical resonant frequency, ω0, are close to the optimal photothermal cooling condition ω0τph = 1. Our study provides an important approach for high effective photothermal cooling and high-sensitivity measurement for force microscopy.     

微悬臂谐振传感器闭环接口和嵌入式频率电路

设计了谐振式微悬臂梁传感器闭环接口和嵌入式频率读出电路。首先,谐振式微悬臂梁传感器和接口电路组成闭环自激振荡系统。为了提高该闭环系统的频率稳定性和频率跟踪性能,引入具有无相差频率跟踪的锁相环电路,并设计放大移相电路以满足闭环自激振荡条件。该闭环系统的频率稳定性可达±0.1Hz,并且能够实时跟踪悬臂梁谐振频率的变化。此外,单独设计了嵌入式的频率读出电路,用于检测并显示悬臂梁的谐振频率。将悬臂梁传感器、接口电路和频率读出电路集成在一起,做出了小巧便携式样机,用该样机可成功探测到体积分数低至约几个10-9量级的DMMP气体。     

Analysis of a Micro-Optomechatronic Force Sensor

Abstract

The purpose of this article is to study the dynamic behavior and modal analysis of a micro-optomechatronic device with primary applications to force sensing and optical attenuation/coupling. The system consists of two initially aligned micro-cantilevers with a narrow gap between them. The light beam enters to the first waveguide and, after propagation along it, couples to second waveguide through the mentioned narrow gap. The externally static or dynamic applied force on the first micro-cantilever deflects it and results in reduced optical coupling between the two waveguides. Changes in this factor are measured to give the properties of the applied force.     

ABNORMAL BENDING OF MICRO-CANTILEVER PLATE INDUCECD BY A DROPLET

The abnormal bending of a micro-cantilever plate induced by a droplet is of great interest and of significance in micro/nano-manipulations. In this study, the physical mechanism of this abnormal phenomenon induced by an actual droplet is elucidated. Firstly, the morphologies of 2D and 3D droplets axe solved analytically or numerically. Then the Laplace pressure difference acting on the cantilever plate caused by the droplet is presented. Finally, the deflections of the micro-cantilever plates driven by the capillary forces are quantitatively analyzed. These analytical results may be beneficial to some engineering applications, such as micro-sensors, MEMS and the micro/nano-measurement.     

焦平面阵列反光板的优化设计与制作

光学读出红外热成像系统中,焦平面阵列(FPA)反光板的初始弯曲降低了系统的光学检测灵敏度。针对FPA的设计制作,提出了两种降低其反光板初始弯曲的优化设计方案:减薄反光板上金层厚度和制作带加强筋的反光板。在理论分析的基础上,设计制作了单元尺寸为200μm的反光板金层减薄FPA,其反光板曲率半径提高至原来金层未减薄FPA的4.71倍,系统光学检测灵敏度提高了5.2倍;单元尺寸为60μm的反光板带加强筋FPA,其反光板曲率半径提高至原来没有加强筋FPA的4.29倍,系统光学检测灵敏度提高了1.18倍。实验验证了理论分析的结果。     

一种新型微梁阵列传感器设计及实现

微悬臂梁传感技术是微纳传感技术研究的热点,仪器装置的研究也从单悬臂梁向微梁阵列的方向发展.本文针对间距为250μm的商品化微梁阵列,提出了一种实现对其弯曲变形的读出系统光路.利用高精度位移平台调节激光器空间位置,使光束实现微距离上平行,并分别照射在阵列梁的相邻微梁上.用位置敏感探测器对两个微悬臂梁尖端反射的激光信号进行...