Zwitterionic Hydrogel with High Transparency, Ultrastretchability, and Remarkable Freezing Resistance for Wearable Strain Sensors

• Published in: Biomacromolecules Vol. 22; no. 3; pp. 1220 - 1230
• Main Authors: Jiao, Qin, Cao, Lilong, Zhao, Zhijie, Zhang, Hong, Li, Junjie, Wei, Yuping
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 08.03.2021
• Subjects: adsorption; biocompatibility; electronic sensing; frost resistance; gellan gum; humans; hydrogels; polyacrylamide; proline; temperature; zwitterions
• ISSN: 1525-7797; 1526-4602; 1526-4602
• DOI: 10.1021/acs.biomac.0c01724

Multifunctional hydrogel with outstanding conductivity and mechanical flexibility has received enormous attention as wearable electronic devices. However, fabricating transparent, ultrastretchable, and biocompatible hydrogel with low-temperature stability still remains a tremendous challenge. In this study, an ultrastretchable, highly transparent, and antifreezing zwitterionic-based electronic sensor is developed by introducing zwitterionic proline (ZP) into gellan gum/polyacrylamide (GG/PAAm) double network (DN) hydrogel. The existence of ZP endows the hydrogel with remarkable frost resistance. The toughness and transparency of zwitterionic Ca-GG/PAAm-ZP DN hydrogel can be maintained down to −40 °C. Also, the zwitterionic hydrogel shows good biocompatibility and protein adsorption resistance. The zwitterionic Ca-GG/PAAm-ZP DN hydrogel-based strain sensor can accurately monitor human motions (such as speaking and various joint bendings) under a broad temperature range from −40 to 25 °C. The zwitterionic Ca-GG/PAAm-ZP DN hydrogel-based strain sensor will be of immense value in the field of wearable electronic devices, especially for extreme environment applications.