Flexible porous silicone rubber-nanofiber nanocomposites generated by supercritical carbon dioxide foaming for harvesting mechanical energy

Triboelectric nanogenerators (TENGs), a promising energy harvesting technology, have been rapidly developed in past few years. However, the specific structure and complicated preparation method greatly limited their mechanical flexibility as well as their potential applications. In this work, a novel and effective strategy to fabricate all-in-one triboelectric nanogenerator(TENG) was reported. The as-mentioned TENG was based on rubber/carbon nano-fiber composites achieved by supercritical carbon dioxide foaming process, which is environmentally friendly and suitable for mass production. Under the optimal condition, 91 V of the open voltage, 2.87 μA of short current and 40 nC of transferred charge was obtained, while this structure contributed to about 10-fold enhancement to transferred charge compared with the single-layer structured TENG at the same area of 4 cm2. The flexible silicone rubber based TENG can collect complex mechanical energy, such as stretching, twisting, bending and compressing. Moreover, when being pasted on soles, it can harvest the mechanical energy from human motion and the outputs can also be regarded as sensing signals which can be used to analyze the gait and sense the motion. This work provides a feasible and effective way to prepare an all-in-one TENG with high outputs, which can bring potential for the industrialized production and widespread application.