A flexible and stretchable polypyrrole/knitted cotton for electrothermal heater

Electrothermal heater (ETH) is very promising in wearable electronic area for its potential thermotherapy and electrical-warming garment applications. To fabricate a suitable conductive material for wearable ETH, knitted cotton is used as substrate for in-situ polymerization of pyrrole monomers, producing conductive polypyrrole/knitted cotton fabric (PKCF) with good flexibility and stretchability. A parallel strategy for current collectors is taken to enhance the temperatures of prepared PKCF from 37.0 to 51.0 degrees C at 8 V. This PKCF provides a service time about 13.5 h in a continuous electrothermal process, keeping a temperature above 35 degrees C. Besides, the PKCF still shows good electrothermal performances after bent or stretched several thousand times, and can be sewn on fabric to realize its electrothermal function in garments, which indicates a promising wearable market.