In this paper we investigate the transient thermoelastic dynamics of a microcantilever subject to laser irradiation. We formulate an initial boundary-value problem (IBVP) describing the transient vibration of a microcantilever caused by laser thermal effects in a vacuum environment. This IBVP includes two PDEs describing the coupled elastic and thermal fields where the elastic beam equation is augmented by viscoelastic damping. We study three laser power distributions having the same total power to analyze the steady state temperature distribution in the microcantilever: (ⅰ) sinusoidal sin(πx/2L), (ⅱ) uniform and (ⅲ) localized δ(x - a). Analytical solutions for a SiN microcantilever with these boundary conditions are determined. We reduce the IBVP to a modal dynamical system and consider its first mode response and obtain its transient decay to a stable equilibrium position. We note that the results of the above analysis are consistent with documented experimental results.
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