Conductive hydrogel-based flexible strain sensors with superior chemical stability and stretchability for mechanical sensing in corrosive solvents

Abstract
Wearable flexible sensors face many harsh environments in practical applications. However, developing corrosion-resistant conductive hydrogel-based flexible sensing materials for applications under harsh conditions remains a formidable challenge because significant damages are caused by the inevitable solvent corrosion on the polymer network structure. Here, a novel conductive hydrogel with superior chemical stability and stretchability was intelligently designed and successfully fabricated by introducing a small amount of N,N '-methylenebis(acrylamide) (BIS) and graphene oxide (GO) as chemical and physical crosslinking agents into the polymer interpenetrating network formed by poly(N-isopropylacrylamide) (PNIPAM) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Benefiting from the introduction of strong chemical bonds and GO nanosheets, the synthesized conductive hydrogel exhibited swelling resistance to strong alkali/polar solvents and surprising chemical structure stability to all solvents. Interestingly, the hydrogel-based sensor could even achieve an accurate and a stable mechanical sensing of tensile strain in a variety of solvents. Furthermore, the hydrogel sensor is featured by strong adhesion, high reliability, and wide sensing ranges for detecting and distinguishing various human motions. Therefore, such design strategy greatly extends the application range of conductive hydrogels in flexible electronic devices and shows great potential in the applications of electronic skins and soft robots in harsh environments (especially in various solvents).

Published in NEW JOURNAL OF CHEMISTRY,Volume 45,4647-4657;10.1039/d0nj05880g,MAR 14 2021

Copyright © Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences
Address: No.18,Tianshui Middle Road,Lanzhou,P.R.China ZIP Code:730000 Tel: 86-0931-4968009 Fax: 86-0931-8277088
E-mail: webeditor@licp.cas.cn Technical support: Qingyun Software