Intrinsically Stretchable, Transient Conductors from a Composite Material of Ag Flakes and Gelatin Hydrogel

ACS Appl Mater Interfaces. 2020 Jun 17;12(24):27572-27577. doi: 10.1021/acsami.0c05378. Epub 2020 Jun 5.

Abstract

Transient conductors are one of the most important components in transient electronics, which attract great attention because of their environment-friendly and biocompatible characters. To meet the requirement for wearable electronics, good stretchability and mechanical durability are needed for the transient conductors. However, it remains challenging to achieve stretchability and transient behavior simultaneously because of a lack of the proper elastomer. Herein, we demonstrate the first highly stretchable and transient conductor from a composite material of Ag flakes and gelatin hydrogel. It shows a maximum stretchability of more than 100% with minimal resistance increase and a good cyclic durability of 1000 cycles of deformation at 20%. The above mentioned good mechanical properties come from the rational design of the conductor with a seamless interface between the hydrogel and Ag flakes. When the conductor is immersed in water at 60 °C, it can be quickly dissolved within 90 s, and the transient behavior can be controlled by tuning the content of the hydrogel in the conductors and dissolving temperature. These properties make the conductor a good wiring candidate for stretchable and transient electronics.

Keywords: gelatin hydrogel; intrinsically stretchable conductors; low resistance; silver flake; transient electronics.