Stretchable slide-ring supramolecular hydrogel for flexible electronic devices

• Published in: Communications materials Vol. 3; no. 1; pp. 1 - 9
• Main Authors: Wang, Shuaipeng, Chen, Yong, Sun, Yonghui, Qin, Yuexiu, Zhang, Hui, Yu, Xiaoyong, Liu, Yu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.01.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/455; 639/638/541; 9/10; Acrylamide; Butanediol; Calcium ions; Chemistry and Materials Science; Crosslinking; Cyclodextrins; Electrical properties; Electronic devices; Human motion; Hydrogels; Ion currents; Materials Science; Mechanical properties; Polymerization; Sodium hydroxide; Solubility; Strain
• ISSN: 2662-4443; 2662-4443
• DOI: 10.1038/s43246-022-00225-7

Slide-ring materials with movable cross-links have received attention due to their excellent mechanical properties. However, due to the poor solubility of polyrotaxane and low synthesis efficiency, their applications are hindered. Here, we use hydroxypropyl-modified α-cyclodextrin (Hy-α-CD) and Acrylamide-PEG 20000 -Acrylamide (ACA-PEG 20000 -ACA) to construct a polypseudorotaxane with good water solubility. Through photo-initiated polymerization of polypseudorotaxane with acrylamide in-situ, the capped polyrotaxane was easily obtained and further cross-linked by 1,4-butanediol diglycidyl ether in sodium hydroxide solution to form a slide-ring supramolecular hydrogel. The hydrogel can be stretched to 25.4 times its original length, which recovers rapidly on unloading, and the addition of Ca 2+ ions during crosslinking enhances ionic conductivity. The Ca 2+ -doped hydrogels are used to prepare wearable strain sensors for monitoring human motion. Slide-ring hydrogels possess good mechanical properties but face synthesis challenges. Here, a slide-ring hydrogel is created via photo-initiated polymerization, with its good mechanical and electrical properties allows it to be used as a flexible strain sensor.