Squeeze film pressure sensors based on SiN membrane sandwiches

[Display omitted] •Squeeze film pressure sensors based on small gap (2–3 μm) sandwiches consisting of SiN membranes with high quality mechanical resonance frequencies in the MHz range.•Observation of pressure-dependent kinetic damping and squeeze film-induced frequency shifts of the mechanical resonances in the rarefied air and transition regimes (10-3-50) mbar.•Observation and model of air-induced coupling between the resonators.•Demonstration of high (several kHz/mbar) pressure responsivity and sub-pascal sensitivity. We realize squeeze film pressure sensors using suspended, high mechanical quality silicon nitride membranes forming few-micron gap sandwiches. The effects of air pressure on the mechanical vibrations of the membranes are investigated in the range 10−3 − 50 mbar and the intermembrane coupling induced by the gas is discussed in light of a squeeze film coupled-oscillator model. The high responsivity (several kHz/mbar) and the sub-pascal sensitivity of such simple pressure sensors are attractive for absolute and direct pressure measurements in rarefied air or high vacuum environments.