Electrical Energy Harvesting From Mechanical Motions by Employing Ferroelectrets Featuring Large Transverse Piezoelectric Activity

Fluorinated ethylene propylene (FEP) ferroelectret films with a parallel tunnel structure and significantly transverse piezoelectric effect are utilized to configurate energy harvesters for scavenging kinetic energy. In the device, a dual-steady cantilever beam structure is adopted to amplify the force input, and a stopper is used to control the strain of the film within an elastic deformation range. Results show that the maximum energy can be delivered to the storage capacitor being with the same capacitance of the device as theoretically predicted. For an energy harvester with an active area of
${30}\,\,\text {mm} \times {10}\,\,\text {mm}$
, the energy delivered to the storage capacitor is 23.5 nJ for one push motion with a displacement of 5.5 mm. The energy can be effectively enhanced by increasing the area of the ferroelectret film and multiplying devices in electrical parallel. These energy harvesters could be implemented in some facilities and devices, such as carpets, floors, and buttons, to scavenge the kinetic energy of motions at low frequencies.