Self-healing and anti-freezing graphene–hydrogel–graphene sandwich strain sensor with ultrahigh sensitivity. Issue 13 (23rd March 2021)

• Record Type: Journal Article
• Authors: Wu, Lu; Fan, Mingshuai; Qu, Meijie; Yang, Shuaitao; Nie, Jia; Tang, Ping; Pan, Lujun; Wang, Hai; Bin, Yuezhen
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 13(2021)
• Page Start: 3088
• Page End: 3096
• Publication Date: 2021-03-23
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tb00082a
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : Hydrogels with specially designed structures and adjustable properties have been considered as smart materials with multi-purpose application prospects, especially in the field of flexible sensors. Abstract : Hydrogels with specially designed structures and adjustable properties have been considered as smart materials with multi-purpose application prospects, especially in the field of flexible sensors. However, most hydrogel-based sensors have low sensitivity, which inevitably affects their promotion in the market. Herein, a strain sensor comprising a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) hybrid hydrogel sandwiched between two graphene layers was successfully constructed in a facile way, and it exhibited many excellent properties including extremely high sensitivity. The incorporation of glycerol ensured the good flexibility and anti-freezing performance of the hydrogel-based sensor even at −15 °C. The dynamic coordination bonds in the hydrogel-based sensor endowed it with excellent self-healing properties. In particular, the sandwich-structured hydrogel sensor showed a very high gauge factor (GF) value of 39 at the strain of 50%, which is much higher than those of most ordinary hydrogel-based strain sensors. A super stable signal value after 5000 strain cycles and a very short response time of 274 ms guaranteed the long-term usability and sensitivity of the hydrogel-based sandwich sensor. More importantly, the hydrogel-based sandwich sensor could detect both large and tiny human motions accurately and instantly in a series of real-time monitoring experiments, showing great potential for intelligent wearable electronic devices.