Wireless bimorph micro-actuators by pulsed laser heating

We report an experimental and theoretical investigation on wireless bimorph micro-cantilever (BMC) actuated by pulsed laser heating. The micromachined BMC consists of a thin gold layer deposited on a polysilicon layer. A pulsed Nd:YAG laser of wavelength = 355 nm and pulse width = 12 ns was used to heat the BMC. The movement of the BMC was measured by a displacement sensor. Experimental results revealed the frequency of BMC vibration upon laser heating. A two-dimensional (2D) discrete model was developed to simulate the laser pulse response of the cantilever. The simulation results agreed well with experimental observation, except the minor differences in vibration amplitudes in the model.