A sonic actuator including a multi-layer membrane having a non-metallic
elastomeric dielectric polymer layer with a first surface and a second
surface, a first compliant electrode layer contacting the first surface
of the polymer layer, and a second compliant electrode layer contacting
the second surface of the polymer layer. The actuator further includes a
support structure in contact with the sonic actuator film. Preferably,
the non-metallic dielectric polymer is selected from the group consisting
essentially of silicone, fluorosilicone, fluoroelastomer, natural rubber,
polybutadiene, nitrile rubber, isoprene, and ethylene propylene diene.
Also preferably, the compliant electrode layer is made from the group
consisting essentially of graphite, carbon, and conductive polymers. The
support structure can take the form of grid having a number of circular
apertures. When a voltage is applied to the electrodes, portions of the
film held at the aperture of the support structure can bulge due to the
electrostriction phenomenon. The resultant "bubbles" can be modulated to
generate sonic vibrations, or can be used to create a variable surface
for airflow control.