Wearable heater composites comprising traditional Hanji cellulose fibers coated with graphene, silver nanowires, and PEDOT:PSS via scalable supersonic spraying

Abstract

Traditional Korean Hanji paper and cotton fabric were introduced as flexible substrates in the fabrication of graphene-coated heaters. Silver nanowires and PEDOT:PSS were added to increase the electrical conductivity of the heaters, thereby enhancing their heating performance. The optimal concentrations of silver nanowires and PEDOT:PSS with respect to that of graphene were identified. These active materials were deposited on flexible Hanji/cotton and non-flexible alumina substrates using supersonic spraying. The proposed Hanji- and cotton-based heaters were light, wearable, stretchable, skin-friendly, and biodegradable. The unyielding alumina-based heater exhibited the highest heating temperature of 275 °C at 13 V. Wearable heater bendability and stretchability were tested considering multiple bending and stretching cycles. Moreover, water boiling and fabric drying were successfully performed using the alumina-based heater. The supersonic spraying deposition technique was used to produce writable and patternable heaters.