Macro-modeling for polysilicon cascaded bent beam electrothermal microactuators

A comprehensively thermal-electro-mechanical analytical model which can precisely predict the performance of polysilicon cascaded bent beam electrothermal actuators has been presented in this paper. This model has taken into account various modes of heat dissipations such as heat loss to circumstance by convection and radiation and to substrate by conduction through trapped air volumes with a temperature range from 300 to 800 K. Furthermore, the influences result from temperature dependent physical parameters of polysilicon are also considered. The model is validated by both 3D-FEA model simulations and available experimental data. With this model, the tip displacement as a function of geometrical dimension as well as many other physical parameters of polysilicon cascade bent beam actuator can be accurately simulated. Moreover, optimization means for achieving high performance of cascaded bent beam actuators are provided based on the theoretical model.