Summary
Nanomechanical resonators often exhibit nonlinear dynamic behaviors due to their small sizes. In this study, we show that the geometric nonlinearity of high-Q Si3N4 nanomechanical string resonators can be substantially tuned by support design. Through careful engineering of support geometries, we control both stress and geometric nonlinearities, tuning nonlinear dynamics from hardening to softening solely by mechanical design. Our work offers new insights into nullifying or enhancing nonlinearity in a purely mechanical manner which is of interest for resonant sensors.
