Zwitterionic Eutectogel-Based Wearable Strain Sensor with Superior Stretchability, Self-Healing, Self-Adhesion, and Wide Temperature Tolerance

Ionicconductive eutectogels have great application prospects inwearable strain sensors owing to their temperature tolerance, simplicity,and low cost. Eutectogels prepared by cross-linking polymers havegood tensile properties, strong self-healing capacities, and excellentsurface-adaptive adhesion. Herein, we emphasize for the first timethe potential of zwitterionic deep eutectic solvents (DESs), in whichbetaine is a hydrogen bond acceptor. Polymeric zwitterionic eutectogelswere prepared by directly polymerizing acrylamide in zwitterionicDESs. The obtained eutectogels owned excellent ionic conductivity(0.23 mS cm(-1)), superior stretchability (approximately1400% elongation), self-healing (82.01%), self-adhesion, and widetemperature tolerance. Accordingly, the zwitterionic eutectogel wassuccessfully applied in wearable self-adhesive strain sensors, whichcan adhere to skins and monitor body motions with high sensitivityand excellent cyclic stability over a wide temperature range (-80to 80 & DEG;C). Moreover, this strain sensor owned an appealing sensingfunction on bidirectional monitoring. The findings in this work canpave the way for the design of soft materials with versatility andenvironmental adaptation.

Automated summary

Ionicconductive eutectogels have great potential in wearable strain sensors due to their temperature tolerance, simplicity, and low cost. In this study, zwitterionic eutectogels were prepared using zwitterionic deep eutectic solvents. These eutectogels exhibited excellent ionic conductivity, stretchability, self-healing, self-adhesion, and temperature tolerance. They were successfully used in wearable self-adhesive strain sensors, showing high sensitivity and cyclic stability over a wide temperature range. The findings pave the way for the design of versatile and environmentally adaptive soft materials.