A micro-electromechanical integrated circuit device comprises a substrate; drive circuitry positioned on the substrate; and a plurality of elongate actuators. Each actuator comprises a fixed end portion fast with the substrate, a free end portion that is spaced from the substrate, and a heating circuit that is connected to the drive circuitry to heat the actuator. A portion of the actuator is formed of a material having a coefficient of thermal expansion such that the material is capable of performing work by thermal expansion. The heating circuit is positioned to generate differential thermal expansion and contraction when heated and cooled to cause reciprocal displacement of the free end portion of the actuator. Each actuator is a laminated structure having a first metal layer and a dielectric layer, the first metal layer being interposed between the dielectric layer and the substrate and defining the heating circuit. The drive circuitry is operable to generate drive pulses of first and second widths, the pulses of the first width being sufficient to cause substantial displacement of the free end of the actuator, and the pulses of the second width being insufficient to cause substantial displacement of the free end of the actuator.