Thermal Microactuator Simplified

Application ID: 16357

This example model consists of a two-hot-arm thermal actuator made of polysilicon. The actuator is activated through thermal expansion. The temperature increase required to deform the two hot arms, and thus displace the actuator, is obtained through Joule heating (resistive heating). The greater expansion of the hot arms, compared to the cold arm, causes a bending of the actuator.

The material properties of polysilicon are temperature dependent, which means that the involved physics phenomena are fully coupled. The actuator’s operation thus involves three coupled physics phenomena: electric current conduction, heat conduction with heat generation, and structural stresses and strains due to thermal expansion.

This example uses the physics interfaces from the base package of COMSOL Multiphysics, and then manipulates them using the Equation View feature.

This model example illustrates applications of this type that would nominally be built using the following products: