A low frequency energy converter for electromagnetic or piezoelectric energy harvesting

Harvesting kinetic ambient energy usually involves the development of converters which operate in the low frequency range (from 0 to 100 Hz). A limit of the harvesters proposed in the literature is their relatively high operating frequency. This work deals with the development of a very low frequency energy harvester based on two counteracting Belleville springs. For a given height to thickness ratio, Belleville springs have nearly zero stiffness over a wide deflection range, thus giving the possibility to build a low frequency system. Either electromagnetic or piezoelectric transduction but also a hybrid of both can be applied to the proposed converter. A preliminary analytical and computational investigation of this solution is presented in the work showing promising results.