Organic piezoelectric energy harvesters in floor

The design, fabrication and testing of piezoelectric energy harvesting modules for floors is described. These modules are used beneath a parquet floor to harvest the energy of people walking over it. The harvesting modules consist of monoaxial stretched PVDF-foils. Multilayer modules are built up as roller-type capacitors. The fabrication process of the harvesting modules is simple and very suitable for mass production. Due to the use of organic polymers, the modules are characterized by a great flexibility and the possibility to create them in almost any geometrical size. The energy yield was determined depending on the dynamic loading force, the thickness of piezoelectric active material, the size of the piezoelectric modules, their alignment in the walking direction and their position on the floor. It was possible to generate up to 2.1mWs per pulse with loads of about 70 kg using a specific module design. An increase of the energy yield at higher loading forces and higher thicknesses of the modules is possible in general. Furthermore a test floor was assembled to determine the influence of the size, alignment and position of the modules on the energy yield.