A nodal analysis model for out-of-plane beamshaped electrothermal microactuators

This paper originally introduces a nodal analysis model for the out-of-plane beam-shaped electrothermal microactuator, which could simulate the temperature distribution along the actuator and the nodal displacement of the actuator. The beam is extracted as the essential element from this kind of actuators. With the temperature correlation along the beam taken into account, the computational complexity is significantly reduced to build the coupled electrothermal model of the beam. The nodal model of the beam with 12 degrees of freedom is utilized to represent the out-of-plane electrothermal microactuator which takes the effect of the change of axial length and large axial stress into account. The temperature dependent thermal conductivity of the beam and the air, heat convection coefficient of the beam surface, and the electrical resistivity are also calculated in the model of the beam. Simultaneously, the change of the gap between the beam and the substrate while actuating which is related closely to the heat transfered from the beam to the substrate, is included in the model. This nodal analysis model of the beam is verified by the published experiment results of the out-of-plane electrothermal microactuator fabricated at MUMPs