Piezo film is a transparent film made of highly polarized polyvinylidene fluoride (PVDF). When external forces are applied, an electrical charge is generated in the material, which can be picked up via the metal-coated outer surfaces. Conversely, when an electrical voltage is applied, a proportional mechanical deformation occurs. The direct piezoelectric effect is used for sensors and the inverse piezoelectric effect for actuators.
Due to the enormous dynamic range and the extreme bandwidth as well as the high flexibility, many measurement tasks can be solved which cannot be achieved with other transducers. Piezo foil can be manufactured as an extremely thin and flexible foil ( starting from 9 µm) in almost any dimensions and can be used as a sensor e.g. for force measurements on surfaces.