Piezoelectric micro actuators

Piezoelectric membrane actuators usually consist of several piezoelectric active and at least one passive layer. Usually the actuator principle is either a plate capacitor assembly or a so called piezo stack. The first utilizes the so called transversal piezoelectric effect, the second the longitudinal piezo electric effect. To both principles there are disadvantages:

• bad efficiency

• complex built up

To utilize surface electrodes might be a very good alternative. Surface electrode are already known with so called SAW-(surface acoustic wave)-components. The actuation with surface electrodes causes an inhomogeneous electrical field in the piezoelectric material. Highest electric field exists at the surface of the substrate and decrease the further moving into the bulk. The inhomogeneous electrical field thus causes an also inhomogeneous mechanical stress distribution, which again inevitably causes the membrane to deflect. This inevitable deflection allows the omission of any passive membrane, which is a great advantage concerning production processes. Another manufactory advantage is the electrical connection on only one side of the substrate. Surface electrodes offer flexible design possibilities, which can influence direction and form of deflection.

Fields of Application

• micro valves
• micro pumps

Contact

Dipl.-Ing. Sandy Zähringer