A fast liquid-metal droplet switch using EWOD

A novel liquid-metal (LM) droplet switch is presented, which addresses the switching speed limitation of previously reported LM switches. An actuation technique based on electrowetting-on-dielectric (EWOD) gives contact line speeds of 50 cm/s. High accuracy positioning by placing the droplet inside a micro-frame allows us to fabricate devices with switching gaps as small as ~10 mum. We report switches with switch-on latency of 60 mus and switch-off latency of 150 mus. The rise and fall time for the switched signal was measured to be below 5 mus. In preliminary tests, 1 W of power was hot- switched for 10´s of cycles without any visual degradation. Combining with the RF performance results and the inherent contact reliability of LM, we are developing microswitches for RF applications.