An electro-thermally and laterally driven polysilicon microactuator

A novel electro-thermally and laterally driven microactuator made of polysilicon has been designed, fabricated, and tested. The operational principle is based on the asymmetrical thermal expansion of the microstructure with different lengths of two beams, but not based on the variable cross sections of the microstructure. A microgripper to demonstrate one possible application of the microactuator is fabricated and characterized. The input voltage of this design is less than 10 dc to produce 20 μm displacement with about 0.6 mJ heat dissipation, and the maximum temperature is less than 600°C. A gripping force up to 2.8 μN can be generated. Simulation results are compared with the experimental data and show good agreement. Some design parameters strongly influencing the performance of the microactuator are discussed also.