A breathable, designable and flexible leather–heater used in wearable thermotherapy

Flexible heaters with personal thermal management capabilities have great potential in thermal therapy applications due to their excellent flexibility, low power consumption, and portability. However, manufacturing wearable heating devices that are breathable, wear resistant and conformal for long-term use is still challenging. To address these issues, we designed a leather heater using breathable, biocompatible, and tailorable leather as the substrate through a simple in-situ polymerization polypyrrole strategy. This heater exhibits excellent heating and mechanical properties (reaching 64°C at a voltage of 5 V with efficient Joule heat generation of 2286 W/m² and uniform temperature distribution, and functioning properly after 1000 cycles of bendability tests). In addition, this heater displays better wear resistance and water vapor permeability rate (38.04 g/(m² h)). The cuttable and sewable of leather gives the strategy ability to be flexibly designed to mold the heater to the specific requirements of different body parts, providing a new approach to wearable thermal therapy.