In this article, an indirectly heated micro-electrothermal actuator is presented. The actuator has a capacitive sensor monolithically
integrated to provide in vivo sensing of the actuator’s displacement. The actuator and sensor are fabricated using the PolyMUMPs
process. Electrothermal and thermal-mechanical models of the actuator have been developed. Simulated displacement versus input
current reasonably agrees with tested results. The integrated capacitive sensor readout is an indicator for the displacement.