A micro-electromechanical device has a substrate (60), a movable element (15), a pair of electrodes (40) arranged on the substrate and on the movable element to move the movable element, and a controller (50) to supply the electrodes. To move the movable element to an intermediate position one or more pulses are applied during the movement, timed to compensate for under or over damping of the movement. This can reduce a settling delay. It can be applied to tunable RF capacitors. To control a decrease in the gap, a single pulse of a maximum supply level compensates for the inherent slowness of the device and over damping. To compensate for under damping, the pulses have a period corresponding to a resonant frequency, and comprise peaks and troughs above and below the final supply level, such that successive ones of the peaks and troughs are closer to the given supply level.