Pull-in analysis of microbeam laminated with LASMP

This work focuses on the pull-in phenomena of electrically actuated size-dependent microbeam laminated with the light-activated shape memory polymer, which can realise the Young's modulus variation under the light exposure. Based on the modified couple stress theory, a size-dependent microbeam model is developed. The dynamic governing equation of the microbeam is derived according to the Hamilton principle and solved by the Galerkin method and Runge Kutta method numerically. The reliability and accuracy of the present method are validated experimentally. The static and dynamic pull-in behaviours of the microbeam are studied when the microbeam is under a purely direct current voltage and alternating current voltage, respectively. Influences of the size effect and dynamic Young's modulus on pull-in behaviour of the microbeam are discussed comprehensively. This research may be helpful and useful in electrostatically actuated microstructure applications and provide a theoretical foundation for designers and engineers.