Flexible and Extendable Honeycomb‐Shaped Triboelectric Nanogenerator for Effective Human Motion Energy Harvesting and Biomechanical Sensing

Abstract Triboelectric nanogenerator (TENG) is an attractive approach to power wearable electronic devices by harvesting energy from the environment. To further improve the electricity generation efficiency, a honeycomb‐shaped triboelectric nanogenerator (H‐TENG) with high spatial density and extendibility for human kinetic energy harvesting and motion monitoring is proposed. The honeycomb structure enables the H‐TENG to extend and stack along the required direction when in restricted space, which consequently achieves enhancive space utilization and power density promotion. 3D‐printed thermoplastic polyurethane as the elastic shell endows the H‐TENG with robust mechanical flexibility, high deformation, and advantageous fatigue resistance. In the output experiment, H‐TENG exhibits excellent electricity generation performance, that the maximum open‐circuit voltage and power density can reach 1500 V and 10.79 W m⁻². In addition, the H‐TENG can not only light 252 white light‐emitting diodes with tapping, power the electronic watch and pedometer with walking, but also can maintain the sustainable running of the electronic thermometer. Moreover, H‐TENG manifests an extraordinary sensible response to the elbow bending of different angles and can estimate the walking speed from the frequency, demonstrating the potential of H‐TENG both as the biomechanical sensor and energy harvester of human movement.