Ultraflexible Transparent Film Heater Made of Ag Nanowire/PVA Composite for Rapid-Response Thermotherapy Pads

• Published in: ACS applied materials & interfaces 2017-02, Vol.9 (7), p.6644-6651
• Main Authors: Lan, Wei, Chen, Youxin, Yang, Zhiwei, Han, Weihua, Zhou, Jinyuan, Zhang, Yue, Wang, Junya, Tang, Guomei, Wei, Yupeng, Dou, Wei, Su, Qing, Xie, Erqing
• Format: Article
• Language: English
• Subjects: Electric Conductivity; Hardness; Hot Temperature; Hyperthermia, Induced; Membranes, Artificial; Nanowires; Oxidation-Reduction; Silver; Surface Properties
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b16853

Ultraflexible transparent film heaters have been fabricated by embedding conductive silver (Ag) nanowires into a thin poly­(vinyl alcohol) film (AgNW/PVA). A cold-pressing method was used to rationally adjust the sheet resistance of the composite films and thus the heating powers of the AgNW/PVA film heaters at certain biases. The film heaters have a favorable optical transmittance (93.1% at 26 Ω/sq) and an outstanding mechanical flexibility (no visible change in sheet resistance after 10 000 bending cycles and at a radius of curvature ≤1 mm). The film heaters have an environmental endurance, and there is no significant performance degradation after being kept at high temperature (80 °C) and high humidity (45 °C, 80% humidity) for half a year. The efficient Joule heating can increase the temperature of the film heaters (20 Ω/sq) to 74 °C in ∼20 s at a bias of 5 V. The fast-heating characteristics at low voltages (a few volts) associated with its transparent and flexibility properties make the poly­(dimethylsiloxane)/AgNW/PVA composite film a potential candidate in medical thermotherapy pads.