Mxene Reinforced Supramolecular Hydrogels with High Strength, Stretchability, and Reliable Conductivity for Sensitive Strain Sensors

Abstract

Conductive hydrogels used as electronics have received much attention due to their great flexibility and stretchability. However, the fabrication of ideal conductive hydrogels fulfilling the excellent mechanical properties and outstanding sensitivity remains a great challenge until now. Moreover, high sensitivity and broad linearity range are pivotal for the feasibility and accuracy of hydrogel sensors. In this study, a conductive supramolecular hydrogel is engineered by directly mixing the aqueous dispersion of MXene with the precursor of N‐acryloyl glycinamide (NAGA) monomer and then rapidly photo cross‐linked by UV irradiation. The resultant PNAGA/MXene hydrogel‐sensors exhibit high mechanical strength (4.8 MPa), great stretchability (630%), and excellent durability. The conductive hydrogel‐based sensor presents excellent conductivity (17.3 S m−1) and a wide scope of linear dependence of sensitivity on strain (0%–125%, gauge factor = 2.05). It displays reliable detection of various motions, including repeated subtle movements and large strain. It also shows good degradation in vitro and antifouling capability. This work may provide a simple and promising platform for engineering conductive supramolecular hydrogels with integrated high performance aiming for smart wearable electronics, electronic skin, soft robots, and human–machine interfacing.

Fabrication of a High-Strength, Tough, Swelling-Resistant, Conductive Hydrogel via Ion Cross-Linking, Directional Freeze-Drying, and Rehydration

“…Comparison of the current hydrogel to previously reported works. − The solid data points represent that the hydrogels had swelling resistance property, while the hollow data points represent that the hydrogels showed no swelling resistance property.…”

Ultrathin Cellulose Nanofiber-Reinforced Ti3C2Tx-Crosslinked Hydrogel for Multifunctional and Sensitive Sensors

“…Due to the excellent performance of MPCB composite hydrogels in electrochemical and mechanical properties, combined with the good biocompatibility characteristics of the PVA/BCNF substrate, it is expected to function as a wearable tensile strain sensing material for monitoring human movement behavior. − To do this, we embedded the fixed fine copper wires at each end of the MPCB for the collection of resistance signals. The sensing performance test was then carried out within an appropriate tensile range (0–250%).…”

Tough and Recyclable Phase-Separated Supramolecular Gels via a Dehydration–Hydration Cycle

“…When exposed to a pure oil, the PSG surface was initially partially wetted with olive oil but was restored to a pristine state by washing with water (Figure d). This property is vital for the use of hydrogels in strain sensors and biomedical applications. ,− …”