Scalable, ultra-high stretchable and conductive fiber triboelectric nanogenerator for biomechanical sensing

A reliable energy device for wearable products and soft electronics must meet the essential needs of high stretchability, stable performance and easy to integration. Despite the substantial advances in material and structural design of two-dimensional planar energy devices, fiber-based electronics remains restricted to scalable fabrication and low conductivity due to the challenges in manufacturing technologies. Herein, we report a homogeneous wet-spun fiber with scalable fabrication and tailorable knittability by in-situ copolymerization dopamine-modified MXene (P-MXene) marring with MXene/TPU (MP) fibers (MMP). The resulting exhibit high stretchability (∼ 675%), good conductivity (4.32 S cm−1) and reliable stability under large deformation thanks to the superior deformation recovery properties of TPU and reliable electrical conductivity of P-MXene ink. Furthermore, the breathable and hydrophobic properties are achieved by a scalable integration of as-prepared fibers due to the porous structure and inherent properties of plain fabric. A fiber-based triboelectric nanogenerator (TENG) constructed by the designed fabric from conductive MMP fiber and aluminum foil shows a maximum open-circuit voltage, short-circuit current and power density of 20.1 V, 0.92 μA and 0.16 mW m−2, respectively. Interestingly, the fiber-based TENG proved a capable to stabilized electrical energy output over 100 times bending with no significant attenuation of voltage signals. As a proof-of-concept, the scalable integrated fabric is used for energy harvesting and human motion sensing via simultaneously real-time responds of electrical signals. This strategy that integrating generators and active sensors simultaneously provide new insights for the development of advanced wearable energy devices, intelligent fabrics, and human-computer interaction.