Experimentally characterising the dynamical landscape of an active MEMS cantilever

Micro- and nano-electromechanical systems (M/NEMS) are in high demand for cutting-edge future technological solutions. Their strongly nonlinear nature is regarded as beneficial for optimising performance metrics for a wide range of engineering applications. As model-free experimentation remains limited to forward time observations, important dynamic features can be left uncharted, resulting in an incomplete dynamical landscape. Here we address this issue by employing experimental continuation - a model-free technique for constructing bifurcation diagrams by tracking steady-states and/or periodic responses directly in a physical experiment. This approach is unexplored for investigating micro-scale systems with fast timescales. Our state-of-the-art experiment investigates an active MEMS cantilever operated as a self-oscillator with a natural frequency of 100 kHz; the fastest timescales of a mechanical system probed with experimental continuation. We explore the cantilever's nonlinear responses to external, periodic excitation via a sequence of one-parameter response curves. By experimentally mapping out the MEMS cantilever's stable and unstable periodic orbits, we expose the dynamic landscape by rendering a multi-valued response surface across a range of forcing frequencies and amplitudes. An atypical, non-Duffing-like bifurcation structure is revealed.