High‐power MEMS switch enabled by carbon‐nanotube contact and shape‐memory‐alloy actuator

A forest of vertically aligned carbon nanotubes (CNTs) is integrated as an electrical contact material with a high‐power, normally‐open switch based on micro‐electro‐mechanical systems (MEMS) technology. A shape‐memory‐alloy (SMA) cantilever is thermally actuated to enable switching between the movable CNT forest and the copper electrode formed on the SMA. The out‐of‐plane SMA actuator provides high forces to enable distributed contacts with the CNT forest, achieving low contact resistances and high ON/OFF resistance ratios. The ON state of the switch shows contact resistances as low as 35 Ω with a dependence on the operating current. The device operation is performed with over 5‐W input powers. Long‐term operation with more than 1 × 10 6 switching cycles is demonstrated. The results indicate that a combination of the CNT‐based contact and the SMA actuator may be a promising path to realizing reliable MEMS contact switches for high‐power applications.