Nanoelectromechanical systems: Potential, progress, & projections

Nanoelectromechanical systems (NEMS) represent the next regime of size reduction beyond the microscale for mechanical devices. In their tiniest, ultimate realization, NEMS will be formed with sub-nanometer scale precision from atomic- and molecular-scale mechanical elements as first envisaged by Feynman (1). Although nanowire and nanotube based NEMS today verge on this domain, their assembly into functional devices remains more of an art than a science, as they are typically fabricated one-by-one by complicated means with low yield. By contrast, the most robust forms of NEMS are currently patterned by top-down methods; in fact their production is now being scaled to enable large-scale integration over 200 mm wafers with minimum feature sizes that are below 50 nm. In this paper I will describe how nanoscale mechanical elements provide benefits beyond the obvious, that is, benefits in addition to the possibility of increased device density. The reduced size of NEMS enables mechanical functionality that completely transcends what is possible at the microscale with MEMS (2). However, size reduction to the nanoscale may not be a panacea for all applications - for some applications larger may still be better!