An electrostatic actuator comprising: first and second comb arrays of
electrodes arranged on a base, the electrodes of the first and second
comb arrays being interleaved; a third comb array of electrodes spring
mounted over the first and second comb arrays, the electrodes of the
third comb array being essentially aligned with the electrodes of the
second comb array; means for applying a first voltage to the third comb
array and a second voltage to the first and second comb arrays to
generate an attractive force acting on the third comb array to move the
third comb array toward the second comb array; and, means for applying
the first voltage to the second and third comb arrays and the second
voltage to the first comb array to generate a repulsive force acting on
the third comb array to move the third comb array away from the second
comb array.