Hybrid dynamic modeling of V-shaped thermal micro-actuators

A new electro-thermal dynamic model for V-shaped thermal micro-electromechanical actuators is proposed. The experimental observation of the dynamic voltage-displacement relationship for a thermal micro-actuator shows a complex characteristic indicating the simultaneous presence of electrical/thermal energy storage and mechanical energy dissipation mechanisms. To completely characterize these mechanisms and yet have a simple representation for control, a new electro-thermal model using the lumped elements concept of dynamic systems is developed. This model represents the electrical-thermal energy conversion phenomenon by an equivalent resistive and capacitive circuit leading to a mathematically well-posed linear differential equation. The Lumped-Element (LE) electro-thermal dynamic model accounts for both conduction and convection losses. Experimental results along with numerical simulations with MATLAB and ANSYS are used to verify the accuracy of the proposed modeling approaches.