Electrochemically Active, Compressible, and Conducting Silk Fibroin Hydrogels
Jiaojiao Yang, Jun Luo, Haidong Liu, Liyang Shi, Ken Welch, Zhaohui Wang, Maria Strømme
Abstract
Silk fibroin-based conducting hydrogels possess hierarchical structural motifs featuring unique properties, but the development of such materials has proven to be challenging. Herein, we develop a novel strategy for the fabrication of a conducting silk fibroin hydrogel based on an interpenetrated network of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and silk fibroin. The hydrogel possesses good electrical conductivity and considerable capacitance and cycling stability due to the existence of the PEDOT conducting network, as well as enhanced mechanical properties such as compressibility due to beta-sheets in the silk fibroin network and Ca2+ cross-linking of the PSS components. A symmetric charge storage device based on conductive silk fibroin hydrogel electrodes exhibited a remarkable areal capacitance of 1.1 F cm(-2) at 0.5 mA cm(-2), as well as a good capacitive response under a compressed state. This combination of compression strength and electrochemical properties makes this conducting silk hydrogel a potential material for unconventional energy storage applications.