风车型低频压电振动能量采集器的研究与设计

基于微机电系统（MEMS）设计了风车型结构的压电振动能量采集器,通过压电效应将低频振动能量转化为电能,用以解决环境中低频能量采集的问题。风车型结构的压电振动能量采集器以硅为基底,以PZT 5A为压电材料,包含上、下电极;4条悬臂梁旋转连接中心质量块与四周固定端,类似于风车结构。数学建模与有限元仿真分析表明,在结构尺寸与材料相同的情况下,圆弧风车型结构的谐振频率较直接连接、直角连接结构的谐振频率更低;4条悬臂梁距离中心质量块越远,谐振频率越低;在0.1g(g=9.8 m/s2)加速度谐振状态下,输出电压约为6.2 V,最大位移接近1.2 mm。基于MEMS工艺,通过IntelliSuite软件研究和定义了风车型振动能量采集器的工艺流程。     

Computer aided modelling and diaphragm design approach for high sensitivity silicon-on-insulator pressure sensors

Silicon on insulator (SOI) pressure sensor diaphragm is a composite structure of the buried oxide and the SOI layer. This paper brings out the inadequacy of the existing analytical model in describing the deflection response of SOI square diaphragms and focuses on the computer aided burst pressure incorporated high sensitivity design approach using IntelliSuite for SOI pressure sensors. The simulation results indicate that the maximum sensitivity is achieved at a side length of 800 μm for burst pressures of 10 and 5 MPa and at 900 μm for burst pressure of 2 MPa. The new modified analytical model developed and presented in this paper for describing the load–deflection performance of SOI composite diaphragm is able to predict the deflection accurately when compared with deflection obtained by IntelliSuite FEA thus illustrating the validity of the computer aided design approach. Further the new model has demonstrated that the existing analytical model overestimates the deflection and hence inadequate for application to SOI pressure sensors. The subsequent piezoresistive analysis carried out on these SOI sensors also confirms these findings and the maximum sensitivity that can be achieved is estimated to be 56 mV/MPa/V for the burst pressure of 5 MPa. The experimental results reported in the literature have been compared with the simulation results to validate the design approach presented in this paper.