A MEMS resonant strain sensor with 33 nano-strain resolution in a 10 kHz bandwidth

In this paper the authors demonstrate a high performance strain measurement system that consists of a polysilicon double ended tuning fork (DETF) resonant sensor and surface mount electronics to measure its output. This system achieves a resolution of 33 nano-strain (nepsiv) in a bandwidth of 10 kHz, and has a noise floor of 60 pico-strain per root hertz (pepsiv/radicHz) up to 1kHz. The 60 pepsiv/radicHz noise floor is equivalent to a displacement resolution of 12 femto-meters per root hertz (fm/radicHz). To the best of the author's knowledge the smallest reported displacement resolution using surface micromachining is 16 fm/radicHz (Geen et al., 2002)