Synergetic effects in composite-based flexible hybrid mechanical energy harvesting generator

Energy scavenging techniques based on piezoelectric and triboelectric effects have become increasingly attractive in the last few years, due to their efficient working processes as well as promising output potentials. Here, we report the fabrication of hybrid generators based on PDMS composite films embedded with a range of functional materials combining both piezoelectric and triboelectric properties. Single effect generators were also fabricated in order to analyze the output contribution of each effect in contrast to the combined effect, and to understand the impact of each material on the piezoelectricity or triboelectricity during the power generation process. An average open-circuit voltage of 48.46 V with an energy conversion efficiency of 31.62% was achieved by a device based on the PDMS composite with PVDF/MWCNT/BaTiO3. The ratio of the triboelectric and piezoelectric effects in the composite generators is introduced and analyzed in this work. Our findings not only indicate that individual materials in a composite can synergistically enhance their intrinsic properties, but also validate that the capacity of composites in converting mechanical energy is far beyond that of the individual material.