Actuation and calibration of charge neutral electrode of a display device

This disclosure provides systems, methods, and devices for actuating, charging and calibrating the charge on a movable electrode in electromechanical systems (EMS) devices. The electromechanical systems device can include a first electrode, a second electrode spaced apart from the first electrode by a gap, a complementary electrode, at least one electrical contact, and a movable third electrode disposed between the first electrode and the second electrode. In one implementation, a method of calibrating charge on the movable electrode of the EMS device includes electrically connecting a complementary electrode to the first electrode to form a compound electrode and applying a calibration voltage across the compound electrode and the second electrode to produce a uniform electric field in the gap. Under the electric field the third electrode moves towards the first electrode until it connects with the at least one electrical contact. Once in contact with the electrical contact, an electrical charge on the third electrode can be changed and calibrated when the third electrode is in a second position. When a mechanical restorative force on the third electrode exceeds the electric force of the uniform electric field on the third electrode, the third electrode then moves to a third position.