A Compact Electrostatic Actuator With Enhanced Contact Force for Resistive Mems Switch

Micromechanical switches are of great interest for microwave electronics, but their implementation is hampered by low reliability. Micron-sized actuators develop low contact force, which does not allow achieving low and stable contact resistance. The force is increased by using large-sized and complex-shaped electrodes, but a compact and simple actuator is preferable. The paper describes methods for increasing the contact force of a MEMS switch with electrostatic actuation. They are demonstrated on a compact actuator with a movable electrode in the form of a 50 μm long cantilever. Selection of vertical dimensions increases the force from 10 to 115 μN and exceeding the required threshold of 100 μN with a reserve. The restoring force also increases and protects the switch from stiction. Combining several actuators and removing intermediate contact bumps additionally increases the specific force by at least 50% compared to a single device.