US Patent 7388186 Optically controlled MEMS devices

An optically controlled mechanical device actuated by electrostatic forces. The device includes electrostatic plates disposed on opposing portions of the device to accumulate charge; conductors to conduct charge to the electrostatic plates from a bias supply; and a photoelectric element having a photoresistive element arranged to affect a quantity of charge reaching the electrostatic plates from the bias supply. The device is caused to actuate to one position when the photoresistive element is exposed to a first level of illumination, and to a another position when the photoresistive element is exposed to a different second level of illumination.