Compact thermally actuated latching MEMS switch with large contact force

Abstract

A novel latching microelectromechanical system (MEMS) switch is reported, which uses a compact configuration of thermal actuators. In the proposed latching mechanism, the necessary displacement of one of the contacts can be reduced, allowing the use of a linear thermal actuator. This linear actuator together with a V-shaped actuator can be aligned next to each other, requiring less area than the classical latching switch design. Another advantage of the proposed design is the high contact force of 1.33 mN, ensuring a stable contact resistance. The latching switch was fabricated in the Metal multi-user MEMS processes (MUMPs) technology and its functionality was successfully tested. In the latched state, a switch resistance of 0.6 Ω was measured

Research Status and Development Trend of MEMS Switches: A Review

“…Dellaert D et al [40] proposed a compact thermal driven latched MEMS switch, as shown in Figure 11. The main structure of the switch is composed of a linear actuator, a V-shaped actuator, a pair of vertically placed contacts and two levers.…”

“…A great deal of effort has been made to address the shortcomings of electrothermal switches. Similar to switches with other driving principles, bistable systems are frequently used for their low power consumption [13,[40][41][42]139,140]. The response speed of MEMS switches can be improved by the actuator optimization of geometry, material properties and driven voltage.…”

“…Generally, an electrical isolation layer is sandwiched between two layers of the driving structure and contact. The electric isolation layer is usually the layer [ 40 , 41 ], or the layer which is formed by plasma-enhanced chemical vapor deposition (PECVD) [ 142 ] and then patterned.…”

“… A compact thermal driven MEMS bistable switch (Dellaert D et al 2015 [ 40 ]): ( a ) the schematic; ( b ) the working process. …”

“…Of course, MEMS switches can be divided into laterally actuated switches [ 13 , 39 , 40 , 41 , 42 ] and vertically actuated switches [ 43 , 44 , 45 ] The displacement of vertically actuated switches is out-of-plane while that of laterally actuated switches is in-plane.…”