Surface engineering of the quality factor of metal coated microcantilevers

We performed noise measurements to obtain the quality factor (Q) and frequency shift of gold coated microcantilevers before and after surface modification using focused ion beam. As a result of our studies, it is demonstrated that surface engineering offers a promising method to control and increase the Q factor up to 50% for operation in vacuum. Surface modification could also lead to deviations from the known Q ∼ P⁻¹ behavior at low vacuum pressures P within the molecular regime. Finally, at higher pressures within the continuum regime, where Q is less sensitive to surface changes, a power scaling Q ∼ P^c with c ≈ 0.3 was found instead of c = 0.5. The latter is explained via a semi-empirical formulation to account for continuum dissipation mechanisms at significant Reynolds numbers Re ∼ 1