A method of driving an element of an active matrix electro-wetting on dielectric (AM-EWOD) device comprise applying a first alternating voltage to a reference electrode of the AM-EWOD device; and either (i) applying to the element electrode a second alternating voltage that has the same frequency as the first alternating voltage and that is out of phase with the first alternating voltage or (ii) holding the element electrode in a high impedance state. The effect of applying the second alternating voltage to the element electrode is to put the element in an actuated state in which the element is configured to actuate any liquid droplet present in the element, while the effect of holding the element electrode in the high impedance state is to put the element in a non-actuated state.