Maximizing microelectromechanical sensor and actuator sensitivity by optimizing geometry

Microelectromechanical systems (MEMS) typically consist of sensor and/or actuator units. In many cases these units are made of beams (modeled as springs) and plates that are subject to external pressure fields, such as electric, magnetic, acoustic or hydrodynamic. Frequently, it is possible to find MEMS devices that can be divided into springs, which control the movement of the device, and an active region, where the sensing or actuating takes place. The overall dimension of a device is often constrained to a small area. In this case it is necessary to find the optimal division between the springs and the active region, which occupy this area, in order to maximize the sensitivity of the device. This paper discusses the relations between the sensitivity of area-constrained MEMS devices and their geometry. The analysis is presented for devices in five different measuring modes, capacitance, tunneling, MOS, piezoresistive and piezoelectric, for a fixed-fixed configuration.     

基于MEMS加速度计的混凝土内部缺陷检测系统

针对冲击回波法进行混凝土内部缺陷检测时,传统的单点有线检测方式存在精度低、检测复杂的问题,提出了一种基于MEMS三轴加速度计的快速检测算法,同时搭建了相应的硬件系统.该系统节点采用MEMS加速度计作为拾振器,利用FPGA作为无线传感器网络节点的控制核心,通过2.4 GHz ISM频段与上位机进行无线通信.经实验测试,系...     

基于MEMS传感器的室内外多源融合导航系统设计

为纠正磁力计的过度偏转行为,使得导航坐标结果更贴合理想预设坐标值,设计基于MEMS传感器的室内外多源融合导航系统。整合多源外接模块电路输出的电量信号,将其分别反馈至MEMS磁力计与微处理器导航元件之中,再根据地图空间定义模块中导航信息数据的传输行为,确定融合信息单元的剩余存储能力,实现多源融合导航系统的硬件结构设计。在此基础上,定义MEMS传感器的实时坐标,通过计算位姿角数值的方式,处理导航点与传感器信息之间的多源融合关系,完成基于MEMS传感器的坐标转换。根据已知的路径节点平移变换原则,得到节点坐标的旋转与缩放结果,完成对导航路径的可视化处理,再结合相关硬件设备结构,实现基于MEMS传感器的室内外多源融合导航系统设计。实验结果显示,与基于降维对偶四元数的导航系统相比,在MEMS传感器作用下,实测角与理想角之间的最大差值只能达到3.7°,能够使得真实导航坐标结果更加贴合理想预设坐标值,符合精准导航的实际应用需求。     

A novel microfluidics integrated biosensor based on a MEMS resonator

Microsystem Technologies - In this paper a sensor based on MEMS resonators is proposed for digital microfluidics applications. The sensor system consists of a disk as active area immobilized for...     

Geometric optimization of van der Pauw structure based MEMS pressure sensor

This paper characterizes a piezoresistive sensor under variations of both size and orientation with respect to the silicon crystal lattice for its application to MEMS pressure sensing. The sensor to be studied is a four-terminal piezoresistive sensor commonly referred to as a van der Pauw (VDP) structure. It is observed that the sensitivity of the VDP sensor is over three times higher than the conventional filament type Wheatstone bridge resistor. With MEMS devices being used in applications which continually necessitate smaller size, characterizing the effect of size and orientation of a VDP structure on the performance of a MEMS pressure sensor is important. In this paper, the effect of relative size and misalignment of the VDP sensor on the sensitivity is investigated using a coupled piezoresistive/stress finite element model. The mode is developed to simulate the full field stress over the deformed diaphragm in which the VDP is diffused. The change in resistivity of the VDP is then analyzed to predict the sensitivity of the VDP structure. Sensor size, position relative to the diaphragm, and angular misalignment of the VDP were varied to determine a theoretical result for the dependence of VDP output on those parameters. It is determined that the performance of the sensor is strongly dependent only on the longitudinal position of the sensor on the diaphragm, and is relatively tolerant of other errors in the manufacturing process such as transverse position, sensor depth, and orientation angle.     

基于MEMS技术的微型磁性开关阵列

为了在二维微驱动系统中实时检出磁性移动块的存在位置 ,提出并试制了一种基于MEMS工艺的微型磁性开关阵列 ,它作为一种位置传感器通过扫描查询方式工作。对该传感器的工作原理、制做工艺做了详细的描述 ,并给出了一些实验结果。     

基于手势识别的智能家居人机交互系统设计

提出一种基于手势识别的智能家居人机交互系统设计,是一种为改善传统智能家居系统中人机交互提出的全新解决方案。利用ST公司的多自由度MEMS传感器平台来获取操作者的手势、体态等特征与控制器进行命令交互,结合近年来高速发展的摄像头视频处理技术、短距无线通信技术,搭建起一个人机交互友好的智能家居感知控制系统。所包含的设计领域有运动采集、模式识别、图像采集与处理、基于STM32的嵌入式软硬件开发等。完成了实验测试,进行了数据分析,结果表明该方案利用简单直观体态控制实现了一种全新的智能家居交互控制方式。     

MEMS传感器的标准化现状与发展对策

随着MEMS传感器在各个领域的广泛应用,传感器领域的标准化工作思路和技术路线发生了变化。论述了目前国内外MEMS传感器标准的现状,并就国内外MEMS传感器标准体系的发展过程、特点、标准体系存在的问题、与现有半导体标准的关系进行了分析探讨,同时,对我国MEMS传感器标准的发展对策提出了建议。     

基于DSP的小型无人飞艇控制系统设计

针对某小型无人飞艇,提出了一种以TMS320F2812DSP芯片为核心的飞行控制系统.为了减轻主CPU负担,飞艇飞行姿态解算任务并不在DSP内执行,而是交给高性能MEMS传感器MTi完成,这样DSP有足够的时间来执行较为复杂的控制算法,从而使系统响应更快,控制精度更高.给出了系统的整体方案设计和硬件选型,并简单介绍了所...     

Analysis and fabrication of a novel MEMS pendulum angular accelerometer with electrostatic actuator feedback

A new type of sensor to directly detect angular acceleration is essential for inertial and control technology. The above interest motivates us to propose a novel micro electromechanical system (MEMS) pendulum angular accelerometer with electrostatic actuator feedback. It adopts a proof pendulum with optimized moment of inertia, suspended to dual anchors by a pair of torsion spring beams, as sensing component. A pair of electrodes are designed as differential capacitors to detect the torsional angular of pendulum, then measure input angular acceleration in sensing axis. Another pair of electrodes are designed as electrostatic actuators for feedback control loop. The structure and operating principle of the MEMS angular accelerometer are introduced. Then, the structure kinetics analysis and signal detecting scheme based on differential capacitors are provided in detail, and the sensitivity and resolution of sensor are derived. Compared with the other MEMS angular accelerometers, the proof pendulum with optimized moment of inertia improves sensitivity and resolution of sensor. The electrostatic actuators feedback loop optimizes the dynamic capability and nonlinearity characteristic. The sensor is fabricated by MEMS fabrication technology. The ANSYS simulation and test results prove the validity of the theoretical analyses. The MEMS angular accelerometer can be used in industrial robots and aircraft by further implementing the signal processing electrocircuit.     

稳像系统中相机姿态信息的采集与存储

介绍了MEMS惯性传感器ADIS16355的特性,阐述了对其进行读写和数据处理的方法,在此基础上,设计了一种应用于图像稳定系统的相机姿态信息采集与存储系统。该系统由FPGA控制,利用ADIS16355进行相机位姿数据的采集,并将采集到的数据存储于系统内的存储介质FLASH中。采集完毕后,通过USB接口实现与上位机的通讯,完成列图像偏移的校正,为提高图像利用率提供了基础。     

MEMS惯性组件的误差特性分析与标定

针对惯性器件输出受工作环境及器件自身噪声影响,导致惯性组件输出信噪比低进而影响系统定位测姿精度等问题,提出MEMS惯性组件误差分析与标定方案。利用Allan方差对MEMS输出进行辨识,对输出信息曲线拟合并确立MEMS器件误差项的误差取值,建立MEMS几何误差模型并设计分立式标定方案。转台实验结果表明,24位置及速率标定方法可实现惯性组件常值误差系数的有效分离与求取,对比器件误差补偿前后的结果,验证了误差修正方案的可行性。     

Manipulator motion control based on a robust acceleration controller

This paper proposes fast motion control of a robot manipulator based on a robust acceleration controller. This acceleration controller is constructed using a mixed sensitivity problem in H_∞ control. The paper discusses the frequency performance taking sensor noise effects and disturbance rejection into account systematically. Moreover, this paper realizes a fast continuous path tracking control system based on the H_∞ acceleration controller. This control system is constructed using only position information, and it makes the multi-degrees-of-freedom motion control system simpler.     

Monolithically Fabricated Microgripper With Integrated Force Sensor for Manipulating Microobjects and Biological Cells Aligned in an Ultrasonic Field

This paper reports an electrostatic microelectromechanical systems (MEMS) gripper with an integrated capacitive force sensor. The sensitivity is more than three orders of magnitude higher than other monolithically fabricated MEMS grippers with force feedback. This force sensing resolution provides feedback in the range of the forces that dominate the micromanipulation process. A MEMS ultrasonic device is described for aligning microobjects suspended in water using ultrasonic fields. The alignment of the particles is of a sufficient accuracy that the microgripper must only return to a fixed position in order to pick up particles less than 100 mum in diameter. The concept is also demonstrated with HeLa cells, thus providing a useful tool in biological research and cell assays     

高于室温环境的热式气体微流量传感器性能分析

为了探索平板微热管的传热特性,了解微热管内不同温度区间的蒸汽传输特性,开展了热式气体微流量传感器及其检测系统的设计。设计了一种便于探索最佳温度测量点的热式微流量传感器结构,利用MEMS工艺进行加工制作,在不同环境温度下对其性能进行了测试,得到了环境温度与热式微流量传感器性能的关系。基于MSP430单片机和C＃语言自主开发了流量传感器检测系统,可对一定范围内的流量进行实时检测,并实时绘制流速随时间的变化曲线。研究表明,采用本文设计的热式微流量传感器结构,可以检测高于室温环境下的微流量气体,并可通过提高加热器温度或改变测温电阻对的测量位置来提高测量灵敏度。     

MOEMS translatory actuator characterisation,position encoding and closed-loop control

Recent developments in optical micro-electro-mechanical systems (MEMS) have produced rapidly oscillating translatory micro-mirrors with out-of-plane mirror displacements exceeding ±100 μm, which have a great potential for various applications requiring high-speed optical path difference modulation. A key factor affecting their practical applicability is a reliable operation control of the MEMS element. Presented here is a pro-active solution combining a laser reference interferometer with a novel position detection scheme and a dedicated control circuitry. By demodulating and processing the laser reference signal, the zero-crossing point of the moving MEMS device can be detected with an accuracy of one interference fringe only. This allows generating a highly accurate mirror control signal in real-time, enabling the implementation of a unique closed-loop control of such MEMS devices and thus ensuring optimally stable MEMS operation and maximal mechanical amplitudes even under varying environmental conditions. The presented solution so provides a vital step forward in the real-world deployment of optical systems using translatory micro-devices.     

一种基于视觉的移动机器人定位系统

具有自主的全局定位能力是自主式稳定机器人传感器系统的一项重要功能,为了实现这个目的,国内外均在不断地研究发展各种定位传感器系统,这里介绍了一种采用光学蝗全方位位置传感器系统,该传感器系统由主动式路标、视觉传感器、图象采集与数据处理系统组成,其视觉传感器和数据处理系统可安装在移动机器人上,然后可通过观测路标物「视角定位的方法,计算出机器人在世界坐标系中的位置和方向,实验证明,该系统可以只的在线定位,     

改进互补滤波在六旋翼飞行器中的应用

针对目前大多数消费级六旋翼飞行器捷联惯性导航姿态解算中,低成本微机电系统(MEMS)器件易发散而导致的姿态漂移问题,提出了一种基于改进一阶互补滤波的姿态解算算法,利用MEMS传感器中加速度计补偿陀螺仪偏差引起的姿态漂移误差,并针对非匀速运动引起的较大误差引入了比例—积分(PI)控制器,用修正后结果代替互补滤波的加速度计输入,从而提高非匀速运动下姿态解算的精度.基于嵌入式处理器STM32,以MPU6050为姿态测量单元的六旋翼飞行器实验平台实验表明:算法计算量小、估计精度高、实时性好,易于在低成本飞行器控制系统中实现.     

基于MEMS声传感器的圆柱壳体振动陀螺振型检测技术

振动陀螺谐振子振型一般采用激光进行非接触式测量,这种方法存在设备成本高、操作复杂、效率低等问题,因此,提出了一种基于MEMS声传感器的圆柱壳体振动陀螺谐振子振型测试方法。该方法利用体积小,指向性高的MEMS声传感器对谐振子振动声场进行高分辨率测量,获得精确的谐振子振动分布情况,建立了谐振子声波测试实验系统,进行了测试实验,并与激光测振仪的测量结果进行比对。实验结果表明,该测试系统具有较高的振型测量精度。这种测试方法成本低,操作简便,测量精度高,可以实现谐振子振型的高精度快速测量,为后续的谐振子修形及陀螺控制提供重要基础。     

基于Si_3N_4薄膜的压力传感器

采用微机电系统(MEMS)技术制造的传感器具有体积小、重量轻、成本低等特点。基于S i3N4压力敏感膜,利用MEMS技术,设计了一种用于测量气压的传感器。采用应变电阻原理对压力进行测量,进行了理论分析计算,设计了工艺过程,制作出了器件样片。这种压力传感器的显著优点是结构简单、工艺过程容易。并且,在50~100 kPa的压力条件下,对传感器进行了测试,其精度达到了0.5%。