Printed graphene electrodes for textile-embedded triboelectric nanogenerators for biomechanical sensing

Abstract

Textile triboelectric nano-generators (TENGs) are emerging as a promising solution for wearable self-powered sensing technology. However, achieving textile TENGs with excellent output performance in conformable devices, while using textile compatible techniques, is still a challenge. In this work, a highly efficient flexible triboelectric textile is developed by using printed graphene electrodes with polydimethylsiloxane (PDMS) and the textile itself as the triboelectric pair. To achieve this, a textile planarization technique with a polyurethane adhesive was employed, along with three different deposition methods: graphene droplet films (GDF), graphene immersion films (GIF), and graphene spray films (GSF). The result was a flexible textile electrode that surpassed non-planarized devices in all three printing techniques, with a 4-fold improvement and a power density of 3.08 µW/cm². Moreover, by increasing the TENG contact area through the use of four parallel devices measuring 3 × 3 cm² each, the power output reached an effective power of 60 µW. The flexible TENG presents a stable output performance under strong deformation and its sensitivity to movement was explored as wearable sensor to monitor biomechanical movements. This work provides a versatile method for constructing flexible triboelectric textile fabrics using only industrial compatible printing textile processes, paving the way to the seamless integration of self-powered wearable sensing technology into textiles.