Advanced Manufacturing of Flexible and Sustainable Triboelectric Nanogenerators Using Waste Materials for Energy Harvesting and Sensing Applications

Growing interest in sustainable materials has led to increased efforts to investigate waste-derived triboelectric nanogenerators (TENGs), using discarded materials such as plastics, agro-residues, and textiles as tribo-layers to transform waste into functional energy harvesters. In this study, we present a flexible and sustainable TENG fabricated through upcycling of waste materials and 3D printing (3DP). Discarded polyethylene terephthalate (PET) plastic bottles were recycled into 3D-printed tribo-positive layers, and graphite from discarded batteries was recovered as a conductive ink for the electrode. Polydimethylsiloxane (PDMS) was used as a tribo-negative layer to produce ReWearSense TENG, which delivered high electrical outputs, including an open-circuit voltage of up to ≈130.8 V and a short-circuit current of up to ≈112 μA, with a peak power density of 33.84 μW/cm² at 700 kΩ load. ReWearSense TENG exhibited excellent durability, sustaining 10,000 cyclic loadings without performance degradation. Practical utility was demonstrated by charging capacitors (1–33 μF) via a rectified output, attaining sufficient stored energy to drive low-power electronics. Outcomes of this study underscore a sustainable route for energy harvesting and self-powered sensing by synergistically integrating recycled polymers, e-waste carbon electrodes, and 3DP to transform selected waste streams into functional energy harvesters with circular-materials integration.