A typical sheet of PSI-5A material has a thickness mode vibration in the neighborhood of 13 MHz and a planar dilatation mode at around 14 KHz. At ultrasonic frequencies large surface area parts draw considerable current and resistive heating of the electrodes becomes the limiting factor. This depends on how the two piezoceramic plates are polarized. Voltage applied in the poling direction only can be raised up to 250 volts. When operated just under its first longitudinal resonance of 15 KHz, the theoretically available output power from the sheet would be around 5 watts.
Resonant designs can be considerably more efficient.
The mechanical energy input under these assumptions would be in excess of 100 watts. Resonant designs can be considerably more efficient. Applying 80 gram force to its tip at a frequency of 60 Hz produces an open circuit voltage of 15V peak between its two electrical leads. Almost any size or shape of piezoceramic element will give off a measurable signal when fastened somewhere on machinery. See 'strain gages'.