Electrostatic–pneumatic activation

Electrostatic–pneumatic activation is an actuation method for shaping thin membranes for microelectromechanical and microoptoelectromechanical systems.^[1][2] This method benefits from operation at high speed and low power consumption.^[3] It can also cause large deflection on thin membranes. Electrostatic-pneumatic MEMS devices usually consist of two membranes with a sealed cavity in between. One membrane-calling actuator deflects into the cavity by electrostatic pressure to compress air and increase air pressure. Elevated pressure pushes the other membrane and causes a dome shape. With direct electrostatic actuation on the membrane, a concave shape is achieved.

This method is used in MEMS deformable mirrors^{[4][5] [6][7][8]} to create convex and concave mirrors.^[9] Electrostatic-pneumatic actuation can double maximum displacement of a thin membrane compared to only electrostatic actuated membrane.^[10]

Moreover, mechanical advantage^[11] is possible by use of electrostatic-pneumatic actuation. Since the cavity is filled with air, mechanical amplification is lower than hydraulic machinery with a non-compressible fluid.

See also

• Electro-pneumatic control