Thermally Driven Polysilicon Actuators for Lateral Displacement

A novel one-mask polysilicon actuator driven by thermal expansion is developed, modeled and tested. The structures are heated by electric current due to resistive dissipation. Thermal strain is magnified by two mechanical mechanisms-lever and parallelogram. The device is tested in air and has a lateral 8 jim-displacement by applying a low voltage (below 3.5 V). The critical current to reach melting point is about 67 mA with the input voltage less than 5 V. The simulation results by analytical and FEM schemes are compared with experimental data. The maximum output forces is measured with a built-in cantilever beam and is calculated to be about 3.3 μN.