A PEDOT:PSS and graphene-clad smart textile-based wearable electronic Joule heater with high thermal stability

Intelligent, highly conductive, robust, and flexible electronic textile-embedded smart devices hold surging interest in the wearable personalized heating system or thermotherapy. However, designing of these structures with desirable thermotherapy properties hinges on certain aspects such as fast temporal responsiveness, localized tunable heating characteristics, reliability, and stable conductive media over several mechanical disturbances as well as readily scalable opportunities. To address these issues, in this work, a facile and scalable dip-coating approach was devised to develop a stretchable, thermally stable, and electroconductive composite cotton textile with reduced graphene oxide (rGO) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) (CGP). The electromechanical properties of CGPs were greatly enhanced due to crystallographic and intra-intermolecular hydrogen bond energy/distance modification. The CGPs fabricated through the systematic dip-coating and drying approach demonstrated outstanding morphological synergies and structural benefits, providing effective endurance against deformations with excellent stable heating up to 60% strain. The composite heater endowed rapidly responsive (15-25 s) Joule heating characteristics, stable heating/cooling cycle and excellent durability to wash. The real-time operation of a wearable fabric heater attached to the finger and palm area of the hand is presented, suggesting its excellent avenues in the personalized electronic healthcare system through tunable and specific region-wise body temperature management for thermotherapy applications.