Mechanical Computation, Redux?

Nanoscale mechanical devices offer the prospect of signal processing, computation, and sensing – at microwave frequencies, sub-nanosecond time scales, and with unprecedented sensitivity and consumption of extremely small amounts of power. In this brief paper I will review the current state-of-the art of nanoelectromechanical systems (NEMS) – with respect to both the underlying fundamental science, and realized (or realizable) applications. The paper concludes with my speculations regarding the future role of nanomechanics in computation, in the context of the rich and rather surprising history of (macroscale) mechanically-based logic.