A semi-interpenetrating network ionic composite hydrogel with low modulus, fast self-recoverability and high conductivity as flexible sensor

Hongyao Ding; Xiaoxu Liang; Qiao Wang; Miaomiao Wang; Zongjin Li; Guoxing Sun

doi:10.1016/j.carbpol.2020.116797

A semi-interpenetrating network ionic composite hydrogel with low modulus, fast self-recoverability and high conductivity as flexible sensor

Carbohydr Polym. 2020 Nov 15:248:116797. doi: 10.1016/j.carbpol.2020.116797. Epub 2020 Jul 23.

Authors

Hongyao Ding¹, Xiaoxu Liang¹, Qiao Wang¹, Miaomiao Wang¹, Zongjin Li¹, Guoxing Sun²

Affiliations

¹ Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau SAR, China.
² Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau SAR, China. Electronic address: gxsun@um.edu.mo.

PMID: 32919535
DOI: 10.1016/j.carbpol.2020.116797

Abstract

There is a growing demand for hydrogel-based sensors due to their biomimetic structures and properties, as well as biocompatibility. However, it is still a challenge to fabricate hydrogel sensor with integration of good mechanical properties and high conductivity. Herein, a tough and conductive hydrogel is developed with semi-interpenetrating network formed by incorporating carboxymethyl chitosan and sodium chloride into polyacrylamide network. The hydrogels have high tensile strength, elongation and toughness, but low modulus comparable to human skin. In addition, the hydrogels exhibit fast self-recovery and satisfactory self-healing capabilities. Owing to the existence of sodium chloride, the hydrogel also has high conductivity, good water retention property and anti-freezing ability. When used as a strain sensor, it demonstrates a broad strain window and shows a high sensitivity in monitoring human motions. This work provides a facile method in fabricating multifunctional ionic conductive hydrogel for applications in wearable electronics and soft robotics.

Keywords: Hydrogen bond; Ionic conductivity; Self-recovery; Semi-interpenetrating network; Strain sensor; Tough hydrogel.