Screen-printed large-area wearable graphene-coated cotton fabric-based thermoelectric generator for solar energy harvesting and health monitoring

Abstract

Wearable fabric-based thermoelectric generators (TEGs) have significant potential in the field of self-powered health monitoring. However, achieving solar energy harvesting, stable thermoelectric performance, wearable comfort and scalable production remains a challenge. This study presents large-area, graphene-coated, cotton fabric-based thermoelectric generators (TEGs) prepared using a screen-printing technique with uniformly dispersed graphene ink. These devices demonstrate excellent thermoelectric performance, with a minimum discernible temperature difference of 0.2 K and a fast temperature response time of 1.721 s, as well as solar energy harvesting capability, cycling stability and durability. Due to their temperature recognition and haptic sensing characteristics, the TEGs can quickly detect the different temperature states of water and convert thermal voltage signals from finger contact into English words. When integrated into a mask, the TEG can monitor respiratory rate by detecting the temperature difference between exhalation and the environment. When embedded in a sleeve, the TEG can collect body heat and solar energy synergistically to achieve self-power supply. This study introduces a straightforward, accessible, and scalable fabrication method for graphene-based wearable thermoelectric generators, which exhibit considerable potential for applications in self-powered wearable electronic devices and health monitoring for individuals with visual impairments.