Body-Biased Multiple-Gate Micro-electro-mechanical Relays

Micro-electro-mechanical relays with multiple gate electrodes ( i.e ., multiple input voltage signals), operated with a tunable body bias voltage, are investigated for more compact and energy-efficient implementation of digital logic circuits. Specifically, a relay design with three gate electrodes of equal area is demonstrated to be capable of performing different digital logic functions for the same input operating voltage ( ${V} _{\textbf {DD}}$ ), by adjusting the body bias voltage. Since the lower limit for ${V} _{\textbf {DD}}$ is equal to the switching hysteresis voltage ( ${V} _{\textbf {H}}$ ), the magnitude of ${V} _{\textbf {H}}$ is investigated for different combinations of transitioning input voltage signals. It is found that ${V} _{\textbf {H}}$ is larger for fewer transitioning input voltage signals, i.e. , reduced effective actuation area of the switching input voltage signal. This can set a practical upper limit for the number of independent gates in a single relay.