Natural biowaste material-based green triboelectric nanogenerators for self-powered gait monitoring

The advancement of triboelectric nanogenerators (TENGs) has attracted increasing interest in recent years due to the growing tension between the increasing demand for energy and the increasing destruction of fossil fuels. For environmentally friendly and self-sufficient devices with high outputs, a TENG based on natural biomaterials is essential. Herein, we report natural biowaste material-based green triboelectric nanogenerators for self-powered gait monitoring. We systematically investigated three novel tribonegative materials: elephant apple, turmeric peel, and taro stem powder. The elephant apple powder-based TENG (EA-TENG) provides the highest output voltage because of its fibrous surface structure. The EA-TENG exhibits an open circuit voltage (V _oc) of 304 V, yielding a maximum power density of approximately 6.4 W m^-2, high stability, achieving a high sensitivity of 2.78 V kPa^-1, and operates in the pressure range of 1-126 kPa. Finally, we showcase its potential by integrating the EA-TENG into flexible sensors capable of accurately monitoring human movements, with a motion detection accuracy of 99.3% achieved using a deep learning-based model. This study comprehensively examines the fundamental triboelectric characteristics of natural fibers and the influence of material composition on output performance, thereby contributing to the field of sustainable energy harvesting technologies and green self-powered sensor applications to reduce electronic waste.