Self-Excitation in Electrostatically Actuated Non-Identical Coupled Curved Microbeams

SummaryWe report on an experimental demonstration of an open-loop self-excitation (OPSE) response in a microstructure composed of two initially curved and non-identical microbeams. One of the beams faces the electrode (beam #1), exposing it to displacement-dependent electrostatic loading, whilst the second beam (beam #2) experiences a “mechanical”, displacement-independent emanating from a truss set in between the two beams. The SE is triggered at high voltages, where one would expect to encounter a pull-in (PI) response. However, the presence of an SE appears to prevent a PI towards the electrode from occurring. The existence of an SE response, which can occur, regardless of any added modification to the circuit, suggests that such a response is an intrinsic feature of the microstructure.