Thermal actuation of thin film microelectromechanical structures

Thermal actuation of thin-film cantilever microstructures is studied. The cantilevers are composed of bilayers of aluminum and silicon nitride fabricated using surface micromachining on glass substrates. The structures are actuated by supplying heat from a TiW microheater located near the foot of the cantilever. The movement of the cantilever in response to a temperature change is due to the difference in coefficients of thermal expansion of the two component materials. This movement is characterized optically as a function of the input power (under quasi-DC conditions) and as a function of the frequency of the applied power (under AC conditions) for different length cantilevers.