Piezoelectric wafers promise new generation of devices

17 Jun 2002

Researchers at NASA's Langley Research Center have taken advantage of a well-known phenomenon exhibited by piezoelectric materials. These materials generate mechanical movement when subjected to an electric current, as in a speaker or actuator, and generate electrical charge in response to mechanical stress, as in certain types of sensors. Dubbed THUNDER, for Thin-Layer Composite-Unimorph Piezoelectric Driver and Sensor, the device could be applied in electronics, optics, jitter (irregular motion) suppression, noise cancellation, pumps, valves and a variety of other fields.

The first generation of THUNDER devices are being fabricated in the lab by building up layers of commercially available ceramic wafers. The layers are bonded using a Langley-developed polymer adhesive. The process results in a prestressed device with significantly improved performance. In addition, the process is controllable and results in highly uniform pieces of hardware.

In the ideal fabrication process piezoelectric ceramic materials would be ground to a powder, processed and blended with an adhesive before being pressed, molded or extruded into wafer form. The result would be increased ability to tailor properties, more flexibility in choosing methods of manufacturing and increased amenability toward mass production. THUNDER wafers could be any practical size from areas of a few square millimeters to several square meters and thicknesses of fractional millimeters to several millimeters.