Clean surface additive manufacturing of aramid paper-based electrically heated devices for medical therapy application

Flexible thin-film heaters with high heat generation performance and good thermal stability have great potential for medical wearable thermal management applications. However, the current preparation of flexible electrothermal devices mainly uses complex chemical deposition methods, which are interspersed with many environmentally unfriendly chemical wastewaters left by the preparation. In this study, we used water-free plasma treatment and magnetron sputtering techniques to prepare conductive silver/aramid fiber paper (Ag/AFP) flexible thin film heaters. The resultant Ag/AFP sputtered with 6 min exhibited fast thermal response and efficient Joule heating characteristics, reaching 120 degrees C in less than 6 s at an applied voltage of 1.2 V. Ag/AFP also provided excellent mechanical properties that could withstand bending, folding, and wrinkling without significant loss of electrical and thermal properties. When used in a thermotherapy patch, the Ag/AFP has unique synergistic antibacterial and thermal therapy. The results showed that magnetron sputtering combined with plasma treatment would provide a clean pathway for fabricating wearable textiles/devices.