MXene-based double-network organohydrogel with excellent stretchability, high toughness, anti-drying and wide sensing linearity for strain sensor

Gel-based strain sensors could be capable of converting external stimuli into electrical signals to realize real-time monitoring, leading to the flourishing development in flexible wearable device. However, how to trade off robust mechanical properties against strain sensitivity is still a great challenge. Herein, the MXene-PAM/SA-Ca2+ double-network (DN) organohydrogel was prepared by a facile one-pot and two-step method. The formation of physical interaction between Ca2+, glycerol and polymer chain endowed the DN organohydrogel with excellent stretchability (1170%), robust fracture strength (540 kPa) and high toughness (3.8 MJ m-3). At the same time, the intrinsic characteristic of glycerol also brought anti-drying and low-temperature resistance to it. Due to doping MXene, the organohydrogel-based strain sensor performed outstanding sensitivity with GF = 1.21, especially a linearity trend in the wide strain range of 0-600%. Similarly, the sensor exhibited satisfactory response time (0.6 s) to external stimuli and accurately capture the motion signal of human, providing a gigantic potential in the fields of e-skin.

Automated summary

In this study, a MXene-PAM/SA-Ca2+ double-network (DN) organohydrogel was prepared using a simple method, which achieved high strain sensitivity while maintaining robust mechanical properties. The gel exhibited excellent stretchability, robust fracture strength, and high toughness, as well as anti-drying and low-temperature resistance due to the physical interaction between the components. The organohydrogel-based strain sensor performed outstanding sensitivity and quick response time to external stimuli, making it highly promising for applications in e-skin.