Micromachined S-shaped actuator

We report on a new type of micromachined electrostatic actuator with an S-shaped film element. The actuator consists of a pair of planar electrodes with an S-shaped film between them. The S-bend film moves back and forth through switching on applied voltage to each electrode plate. An advantage of this actuator is that it allows vertical film displacement to the order of several hundreds of micrometers. The actuator is suitable for gas control devices which require large conductance under rarefied pressure conditions. We made a prototype S-shaped microactuator by using micromachining technologies. It was composed of three stacked wafers. We succeeded in constructing an S-shaped film element with a structure height of 220 μm and a thickness of 0.4 μm. The S-shaped film was able to be operated by electrostatic force when the applied voltage was about 70 V