Energy and Latency Optimization in NEM Relay-Based Digital Circuits

Digital circuits based on nanoelectromechanical (NEM) relays hold out the potential of providing an energy efficiency unachievable by conventional CMOS technology. This paper presents a detailed analysis of the operating characteristics of fabricated curved cantilever NEM relays using a comprehensive physical model. The mode of energy distribution within the electrical and mechanical operational domains of the relay is described in detail and the energy saving achievable by the technique of body-biasing is quantified. The analysis further reveals that the latency in a relay can be much larger or much smaller than the nominal mechanical delay depending on the point of actuation in the oscillation of the beam that takes place after pull-out. The methods that can utilize this phenomenon to reduce the latency of relay-based circuits are discussed, thus addressing one of the biggest challenges in NEM relay-based design.