Adiabatic Logic Gates for Ultra-Low-Power Operation Using Contactless Capacitive MEMS

We propose a concept of ultra-low-power logic gates based on flexural capacitive MEMS. Contactless operation avoids reliability issues faced by micro-electromechanical relays and allows for elimination of static losses. Furthermore, capacitive information encoding allows recovery of the invested charges, which makes adiabatic operation possible. This new paradigm is thus expected to be much more energy efficient than any CMOS logics that inherently presents static and dynamic losses. The design of an inverter (NOT) gate based on a complementary architecture of combdrives is detailed. They operate in the unconventional configuration where the initial overlap of the comb fingers is zero for the sake of a minimum usage of energy of the gate. Fabrication of proof-of-concept devices is presented using a silicon-on-insulator technology with 0.5 μm critical dimensions.