Method for overcoming the unwanted displacements of an electro-thermally actuated microgripper

Thermal microactuators are based on the principle of material deformation due to heat generated by Joule effect. As a class of microactuators, the microgrippers are promising tools for manipulation of micro and nano scaled objects. The designs of two models of SU-8 microgrippers electro-thermally actuated are described. A simple design for an electro-thermaly actuated polymeric microgripper is compared with an improved design using a pair of heaters on both sides of the microgripper. We demonstrated that it is possible to reduce the unwanted out of plane displacement, the second model capable of being more stable to the out of plane deflection, generated by the stress, when a voltage is applied. Electro-thermo-mechanical simulations based on finite element method were performed for each of the model in order to make a comparison between the results. Preliminary results on the fabrication of the last model, using a surface micromachining technique and an SU-8 polymer as functional material are presented.