Embodiments of the invention provide robust electrothermal MEMS with fast thermal response. In one embodiment, an electrothermal bimorph actuator is fabricated using aluminum as one bimorph layer and tungsten as the second bimorph layer. The heating element can be the aluminum or the tungsten, or a combination of aluminum and tungsten, thereby providing a resistive heater and reducing deposition steps. Polyimide can be used for thermal isolation of the bimorph actuator and the substrate. For MEMS micromirror designs, the polyimide can also be used for thermal isolation between the bimorph actuator and the micromirror.