Abstract: A localized gap plasmon resonator includes: a pad including: a first plasmonic material to support a surface plasmon; and a first plasmon surface; a nanoelectromechanical (NEM) member disposed opposing the first plasmon surface of the pad and spaced apart from the pad by a plasmon gap, the plasmon gap supporting a plasmon resonance; and a plasmonic nanoprism disposed on the NEM member and including: a second plasmonic material to support a surface plasmon; and a second plasmon surface, such that: the second plasmon surface of the plasmonic nanoprism opposes the first plasmon surface of the pad; and the pad, the plasmonic nanoprism, and the plasmon gap support a localized gap plasmon (LGP) mode.