Design and Fabrication of An Electro-Thermal Microactuator with Multi-Lateral Motion in Plane

• Main Authors: Yi-Kun Chen, 陳義坤
• Other Authors: Chia-Lung Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/86931418016452574313

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 92 === In this paper, we present a new electro-thermal microactuator to have multi-lateral motion in-plane by only varying voltage potentials at two contact pads. The new microactuator combine the traits of two basic electro-thermal microactators proposed by Guckel (1992) and Pan and Hsu (1997), respectively. The design principle is based on the asymmetrical thermal expansion of the structure with (1) the different lengths and widths of the beams, (2) the varying resistivity of the beams by selective doping, and (3) the rigorous control of thermal boundary conditions. Analytical models are derived to describe the electro-thermo-mechanical performances of the actuator. The commercial finite element package ANSYS is used to demonstrate the feasibility of the design principle, to verify the analytical results, and to characterize the microactuator in details under large deformation theory or under complex heat transfer conditions. Design parameters (including the structural dimensions, selective doping and heat transfer conditions) significantly influencing the performance of the microactuator are discussed. Thereafter, the optimal structures of the microactuators cab be obtained by varying the dimensions and resistivity of the beams to get proper performance of the microactuator. Conventional silicon-based micromachining techniques compatible with IC processes are used to fabricate the microactuators. Because Phosphorous-doped LPCVD (low pressure chemical vapor deposition) polycrystalline silicon films have been widely used in a variety of MEMS and IC applications, they are used herein to demonstrate the effectiveness of the proposed microactuators. According to the simulation and experimental results, it is found that only low input voltages (0~7V) are required to achieve displacements in microns with the operating temperatures below 300℃, and hence the simple CMOS electronics can be incorporated on the same chip to control the devices.