FINITE ELEMENT MODELING OF RESONATING MEMS MICRO-HEATER STRUCTURES FOR DESIGN VERIFICATION AND OPTIMIZATION

摘要

The object of this project is to develop finite elementrncomputer models of SOIMUMPs fabricated MEMSrnmicroheater structures to predict their performancernaccurately for use as a design verification andrnoptimization tool. Primary performance criteria for thernmicroheaters are (1) temperature uniformity, (2) highrnheating efficiency and (3) fast thermal response time.rnModels of SOI-MEMS micro-heaters were developedrnemploying COMSOL Multiphysics? platform. In order tornestablish the subdomain and boundary conditions for suchrnmicroscaled structures, parameters were extracted byrncomparing experimental displacement results to FEMrnsimulated displacement results of a hot-arm-cold-armrnmicrogripper (thermal microactuator) structure, fabricatedrnon the same wafer with the microheaters. Results of thernmicrogripper experiments were then used to narrow thernrange of plausible values for a comprehensive sweep ofrnour primary design, the resonating microheater.rnParameters to be established are temperature coefficientrnof resistance and convective (to air) heat transferrncoefficient; values of each in the microgripper providingrnmost accurate agreement with experiment are found to bern.0055°C-1 and 200/100 (top/bottom and sides) W/m2/°Crnrespectively. Finally, results of the microgripper-guidedrnparametric sweep of the microheater show a maximumrnrange of temperature differences from 2.87% at 32°C torn4.71% at 270°C and very high heating efficienciesrn(4.29°C/mW – 8.42°C/mW). Thermal time constants werernfrom 2.38ms to 1.40ms.