Vibrational IR MEMS sensor: Application of torsion-bars tension-enhanced by bio-nano crystallization for highly sensitive detection

A thin-film MEMS infrared (IR) sensor using torsional resonators was developed to achieve high sensitivity. The torsional resonators consisted of bimaterial; a tense Si thin-film and a metal film for IR absorption. Light incidence induced out-of-plane displacement of the resonators thereby shifting the resonant frequency of torsional vibration. To improve the response of the frequency shift, tension in the Si thin-film was enhanced by metal-induced lateral crystallization using biomineralized Ni nanoparticles and a lightweight metal was deposited onto the resonator to obtain flat profile. Response to heat and light incidence were discussed for the fabricated devices.