Combinational Logic Design Using Six-Terminal NEM Relays

This paper presents techniques for designing nanoelectromechanical relay-based logic circuits using six-terminal relays that behave as universal logic gates. With proper biasing, a compact 2-to-1 multiplexer can be implemented using a single six-terminal relay. Arbitrary combinational logic functions can then be implemented using well-known binary decision diagram (BDD) techniques. Compared to a CMOS-style implementation using four-terminal relays, the BDD-based implementation can result in lower area without major impact on performance metrics such as delay, and energy (when the relays are scaled to small dimensions). Although it is possible to implement any combinational circuit with a single mechanical delay, the relay count can be significantly reduced for complex logic functions by allowing multiple mechanical delays.