*3.8.4 Tennis racquets*

A somewhat unusual application for piezoelectricity integrates piezoelectric fibers into the throat of a tennis racquet along with a microcontroller in the handle. When the tennis player strikes the ball, the racquet frame deflects and generates an electric output that is boosted, reversed, and fed back into the fibers [14]. This is an attempt to cause destructive interference and dampen structural vibration.
