Flexible Hybrid Energy Harvester based on Thermoelectric Composite Film and Electrospun Piezopolymer Membranes

A hybrid energy harvester that consisted of thermoelectric (TE) composite film and electrospun piezoelectric (PE) polymeric membranes was constructed. TE composites were fabricated by dispersing inorganic TE powders inside polyvinylidene fluoride elastomer using a drop-casting technique. The polyvinylidene fluoride-trifluoroethylene, which was chosen due to its excellent chemical resistance, mechanical stability, and biocompatibility, was electrospun onto an aluminum foil to fabricate the ultra-flexible PE membranes. To create a hybrid energy harvester that can simultaneously convert heat and mechanical energy resources into electricity, the TE composite films attached to the PE membrane were encapsulated with protective polydimethylsiloxane. The fabricated energy harvester converted the outputs with a maximum voltage of 4 V (PE performance) and current signals of 0.2 μA (TE performance) under periodical heat input and mechanical bending in hybrid modes. This study demonstrates the potential of the hybrid energy harvester for powering flexible and wearable electronics, offering a sustainable and reliable power source.