Triboelectric nanogenerator for entire stroke energy harvesting with bidirectional gear transmission

Triboelectric nanogenerators (TENGs) play an important role in harvesting mechanical energy from the environment. Most of their mechanical movements are reciprocating. And the mechanical energy always exists during the entire stroke, which involves the downward and ascending movements. To effectively harvest mechanical energy in the entire stroke, a bidirectional gear transmission triboelectric nanogenerator (BGT-TENG) is developed. The BGT-TENG comprises a platen, a bidirectional gear transmission system, a flywheel and shells. In a series of experiments, optimal setting parameters such as the flywheel mass and the size of the flexible fluorinated ethylene propylene (FEP) film were determined. When the BGT-TENG is acted upon by an external random excitation, reciprocating motion of the platen is transferred to a continuous operation of the flywheel through its bidirectional gear transmission. The BGT-TENG generates electric energy of 2.4 mJ under the low frequency bidirectional equi-spaced excitation of 3.5 Hz. Using a rectifying circuit, the BGT-TENG can power 375 light-emitting diodes, and a digital thermometer is powered successfuly. The results imply that the BGT-TENG has a wider application prospect in the field of energy harvesting.