Direct 3D-printed triboactive polymer layers on stretchable conductive fabric for high-performance T-TENGs

Printing polymer materials onto fabrics presents significant challenges, particularly due to high-temperature printing requirements and adhesion issues. This investigation presents a novel approach to fabricating high-performance textile-triboelectric nanogenerators (T-TENGs) by direct 3D printing of polymers onto stretchable conductive fabrics using a low-cost fused filament fabrication (FFF) method for wearable energy harvesting and sensing applications. Achieving strong interfacial adhesion between triboactive polymers and flexible conductive fabric substrates remains challenging. This work effectively demonstrates the integration of polypropylene (PP) via direct 3D printing on fabric electrodes, enabling precise surface patterning and enhanced mechanical stability. Systematic evaluations were conducted to assess the impact of surface patterning, single-layer (SL) and double-layer (DL) printing configurations, and varying thicknesses. These studies revealed that surface engineering plays a critical role in optimizing triboelectric properties. The fabricated PP-based T-TENG exhibited a maximum output voltage of approximately 193.3 V, a peak current of around 17 μA and a peak power density of up to 2043 mW/m². Direct 3D printing enabled intimate and uniform bonding between the dielectric layer and the fabric electrode, resulting in higher output than conventional electrode attachment approaches. Notably, the newly developed T-TENGs are highly flexible, scalable, shape-adaptable, washable, and mechanically stable. The successful integration of these T-TENGs into an Internet of Things (IoT)-enabled adaptive touch sensing system demonstrates the real-world applicability. Further, this work advances the potential of self-powered wearable devices for a broad spectrum of applications in healthcare, robotics, and environmental monitoring by enabling real-time tracking and remote monitoring through IoT connectivity.