Fabrication of microcellular TPU/BN-CNT nanocomposite foams for high-performance all-in-one structure triboelectric nanogenerators

In recent years, triboelectric nanogenerators (TENGs) has become one of the strongest energy solutions for the continuous operation of the next-generation wearable devices. However, a broad application of TENGs was often limited due to a number of essential accessories required to complete relative motions. This study reported a thermoplastic polyurethane (TPU) based all-in-one structured TENGs (A-TENGs) integrated with one-dimensional carbon nanotubes (CNT) and two-dimensional boron nitride (BN). When the microcellular pores were introduced by supercritical treatment, the BN becomes were partially ejected and exposed to the surface of TPU/CNT matrix. The exposed BN particles and CNT/TPU were in contact when TPU/BN-CNT composite was mechanically deformed. This resulted in a contact-release motion between them generating electricity. The average output current and voltage from 1 cm2 area of proposed TPU/BN-CNT nanocomposite foam was around 70 nA and 17 V, respectively. To the best of author's knowledge, this was the first time to employ BN for practical application of TENGs. Furthermore, it was clearly demonstrated that the proposed TENGs can be used to monitor human motions without external power soures. This work suggested a novel A-TENGs system wiith a new triboelectric pair, which can be adapted to polymer processing industry. This will be one of the most powerful candidates for future power sources for wearable devices.