Mechanically Tri-Stable In-Line Single-Pole-Double-Throw All-Metal Switch

This paper reports on a tri-stable mechanically interlocking switch mechanism based on laterally moving curved-electrode electrostatic actuators. The in-line switches are realized in a true single-pole-double-throw configuration (SPDT) with three mechanically stable states: 1) input to first output; 2) switch off; 3) input to second output (on-off-on). The devices are fabricated in a silicon-on-glass process and are coated with sputtered gold, resulting in an all-metal switch. The switches feature active opening capability for which the curved-electrode actuators are utilized in their end-position where they develop their maximum force to guarantee a very large opening force which makes the switch less susceptible for contact stiction.