An energy harvesting system is presented that converts energy out of flowing media, like water or wind. Without the need for any rotating part the harvester converts the energy out of the bending of a piezoelectric cantilever. A bluff body, which the cantilever is attached to, causes vortices and therefore pressure differences above and beneath the cantilever. Thus the cantilever oscillates and generates an alternating voltage. A first macroscopic model proofed this working concept for air and water. Measurements showed good coupling between flow velocity and power generation. Furthermore a self synchronization of different cantilevers could be observed in water. A second model of the harvester was build with improved distribution of piezoelectric layers. To store and distribute the generated energy of the harvester, it was combined with a low power circuit that was developed, too. Therefore, a complete autonomous system that is able to supply a load and the necessary electric circuit with power is presented.
First, energy harvesting from floor is described as a sustainable method to generate electrical energy. Different solutions, available on the market, will be considered and evaluated. Second, the design, fabrication and test of organic piezoelectric harvesting modules will be discussed. These modules shall be used directly beneath the firstlayer of the floor to gain energy from people walking across this area.The harvesting modules consist ofa polymeric thin film of PVDF. PVDF shows piezoelectric properties if it was be stretched during or after the foil fabrication. Besides this stretching, it is required to polarize the PVDF, too. This polarization process is fortunately realized at temperatures above room temperature. The better the polarization process the better the conversion efficiencyof the material. Although the values of voltage conversion are not as high as with PZT-ceramics, PVDF offers some interesting properties making it very useful for such harvesting applications. 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 fabrication process of the harvesting modules is very simple and suited for mass production. Harvesting modules are built upas roller-type capacitors.The energy yield was determined depending on thedynamic loading force and the thickness of piezoelectric active material.An increase of the energy yield at higher loading forces and higher thicknesses of the modules is possible in general.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.