Displacment amplification and latching mechanism using V-shape actuators in design of electro-thermal MEMS switches

This paper reports two unique mechanisms using "V-shape" electro-thermal actuators to realize large displacement and reliable contact in MEMS switches. The first mechanism is a novel displacement amplification system that enables a large in-plane traveling distance for closing the gap between switch contacts. The structure features a movable end and pivot joints connecting to the amplification beam that can result in smaller actuating force distinguishing this mechanism from others. The second mechanism involves a unique latching system to provide a large lateral force for reliable contact. In both mechanisms, out-of-plane displacements are minimized due to the structural symmetry of the "V-shape" actuators. The devices are fabricated using PolyMUMPS process. At 1 V driving voltage for 2 pairs of 3-arm V-shape actuators, the displacement amplification system provides a gain of ~6.5 while consuming 2×3.8 mW power. Each 4-arm V-shape latching actuator generates ~2.7 μm displacement and ~240 μN contact force with a power consumption of ~2.2 mW.