Viscous damping of microcantilevers with modified surfaces and geometries

Noise measurements were performed to determine the quality factor Q and the resonating frequency shift as a function of gas pressure P for microcantilevers with modified surfaces and geometries. In the molecular and continuum regimes, energy loss is dominated by the surrounding fluid leading to reduction of the Q factor and shift of the resonance frequency by Δf, which becomes significant in the continuum regime showing sensitivity on surface changes. This is shown via three methods: frequency shift Δf vs. P, Q factor vs. P, and direct calculation using surface roughness details acquired via atomic force microscopy.