ACS applied materials & interfaces | 2019
One-step preparation of highly stretchable, conductive and transparent polyvinyl alcohol-phytic acid hydrogel for casual writing circuits.
Abstract
Conductive hydrogels have shown great potential applications in a wide field, including artificial intelligence devices and biomedical engineering. However, it still remains a great challenge to develop a facile and cost-effective approach to achieve a conductive hydrogel with favorable qualities. Herein, we have changed the traditional ingredient of polyvinyl alcohol (PVA) hydrogel by the addition of phytic acid (PA), which could obtain a conductive hydrogel through one freezing-thawing cycle. The PVA-PA hydrogel holds several virtues of large stretchability (about 1100% strain), excellent conductivity (1.34 kΩ·cm) and high optical transparence (about 95%). By assembling the PVA-PA hydrogel into a wearable strain sensor, the gel-based sensor has a good performance for real-time monitoring of human daily activities and health conditions. Moreover, one formula of PVA-PA sol ink could fast convert to the gel state just by injected on a flexible substrate under ice-bath, which would satisfy the demand of casual writing circuits. This one-step prepared method of PVA-PA hydrogel may open an innovative avenue for the fabrication of easy-molding and functional hydrogel with only two components under a mild ambient.