Polyurethane aerogel-based triboelectric nanogenerator for high performance energy harvesting and biomechanical sensing

This work presents a high performance triboelectric nanogenerator (TENG) based on nanoscale porous polyurethane aerogel (PUA) for effective mechanical energy harvesting and biomechanical sensing. Through a controlled process, flexible thin films of PUA are fabricated and corresponding physical and chemical properties are characterized to be embedded into the TENG device. The electrical output characteristics of the PUA-TENG is investigated using the aerogel films with different porosity levels ranging from 0 to 94% open-cell content. The PUA-TENG with 33% open-cell content shows the highest performance where the open-circuit voltage and short circuit current are 3.5-times higher than those of the TENG with non-porous film. The improvement is due to the enhanced capacitive and surface properties of the applied polymeric aerogel film. The PUA-TENG is capable of charging different capacitors for energy harvesting applications under mechanical agitation. The device can be mounted on a human arm for monitoring the arm motion as a biomechanical sensor. Therefore, the PUA-TENG demonstrates to work effectively for both energy harvesting and biomechanical sensing.