Research For Electro-Thermal Microgroppers

Microgrippers are needed for microassembly and microoperation.In recent years several designs based on different drive mechanism have been demonstrated,and they are successful used for micromanipulation of biological cells and lenses.Thermal microgripper rely on thermal expansion of an electrically heated so-called'hot-arm'is one of the hotspots in MEMS microgrippers. The main research contents are presented as follows:(1)An electro-thermal actuated microgripper are described in detail.The design of microgripper structure is based on a simple actuator consisting of three parallel beams connected by an end bar.And the actuator is able to both open and close. The multi-energy mathematic model of the electrothermal microgripper was developed .The temperature distribution and deflection for the driving voltage were analyzed with analytic solution.(2)A finite element model of the microgripper was developed with ANSYS.Output displacement and gripping force of the microgripper dependent upon the change of structure parameters were simulated.The deformation and stress distribution of microgripper was gained by a predigest model of grasping.At the precondition of same boundary condition and structure dimension ,the output displacement and gripping force of microgripper was compared with two-hot-arm actuator.(3)Through modal analysis, the several former natural frequency and mode shapes were gained.The response of the microgripper to the impact is analyzed by taking it as a distributed parameter system.