Microelectrical device

A microelectrical device comprising a ferroelectric layer disposed between two generally parallel electrodes at least one of which is movable, the electrodes having a closed position in which the ferroelectric layer is sandwiched between the two electrodes and an open position in which the or each movable electrode is spaced from the ferroelectric layer by a gap, and means for biasing the movable electrode(s) towards the open position, the electrodes being connectable to a voltage source for applying:

• a first voltage pulse to move the movable electrode(s) from the open to the closed position against the action of the biasing means,
• a low or zero voltage, and
• a second voltage pulse of opposite polarity to the first voltage pulse;
• such that when the or each movable electrode is moved to the closed position by the application of a first voltage pulse the ferroelectric layer is polarized to hold the movable electrode(s) against the ferroelectric layer, and when said low or zero voltage is applied the or each movable electrode is held in the closed position by remnant polarization of the ferroelectric material until the application of the second voltage pulse which cancels the remnant polarization of the ferroelectric material to allow the movable electrode(s) to be moved to the open position by the action of the biasing means.