Composite Wearable Textile Materials with Spatial Control of Joule Heating

Flexible heaters have gained interest as a viable option for thermal management and heat generation in wearable devices. Various conductive polymers, fibers, and textiles have been studied for their effectiveness as Joule heaters. Most existing methods provide uniform heating over an area but do not allow a spatially varying heat flux. In this work, we designed a low-profile composite textile material that enables spatial control of the localized level of heating by tailoring the geometry of an integrated serpentine conductive textile pathway. The composite material is composed of three layers bonded by heat sealing—a thermoplastic polyurethane (TPU)-coated supportive backing textile, a serpentine-patterned conductive textile, and an electrically insulating TPU top layer—enabling facile fabrication. Using an analytical approach to determine the relationship between power density and material design, a desired spatial distribution of heat flux can be achieved. This material provides a customizable and repeatable heating method for applications in wearable devices for thermoregulation and thermotherapy, actuation mechanisms for soft robots, and climate control devices for temporary or portable shelters.