A nonlinear model for a self-powered electromechanical actuator using radioactive thin films

This paper presents a nonlinear model for the self-powered electromechanical actuator using radioactive thin films. The theoretical formulations are based on Hamilton principle and include the effects of geometric nonlinearity due to nonlinear curvature and load nonlinearity due to radioactive source. Two models which named as constant coefficient collector current model (CCM) and variable coefficient collector current model (VCM), respectively, are presented to formulate the electrostatic force. The nonlinear governing equations based on the CCM and VCM are solved using Galerkin principle and iterative method. The present nonlinear model is validated through direct comparisons with the experimental results in open literature. Numerical results show that the CCM is valid for small initial distance only whereas for large initial distance, the VCM must be used for accurate analysis. The effects of initial distance, cantilever beam length and thickness on the drop-down time of the self-powered electromechanical actuator are also discussed.