Surface micromachined metallic microactuator with buckling characteristics

This paper presents a new class of thermally driven actuators. Thermally induced buckling of metallic microbridges has been used for actuation. The heating elements were realised by an polysilicon layer, isolated by siliconoxide, under the metal. The micro bridge was manufactured by electroplating and finally completed by a sacrificial layer etching. Polysilicon was used as a sacrificial layer material. During heating of the polysilicon heaters, the high thermal expansion coefficient of the metallic bridge produces a large compressive stress and results in a buckling of the structure.