Highly Deformable and Durable Hydrogels through Synergy of Covalent Crosslinks and Nanosheet‐Reinforced Dynamic Interactions toward Flexible Sensor

Abstract

AbstractIntegration of both excellent mechanical performance and remarkable durability into composite hydrogel materials is highly demanded yet challenging. Herein, a synergistic strategy of combining covalent crosslinks with nanosheet‐reinforced dynamic interactions is developed for the design and fabrication of deformable and recoverable nanocomposite hydrogels. Layered double hydroxide nanosheets and a trace amount of covalent crosslinks are simultaneously incorporated into the network, providing profound synergy in mechanical enhancement and durability extension. The resultant materials displayed high deformability (stretchability >1100%, compressibility >90%), considerable springiness and resilience, rapid and excellent recovery over 2000 cycles of compression and retraction as well as a 100% hysteresis ratio after only 1 min during large stretching. Notably, these networks are also transparent and ionically conductive. To demonstrate the utility, a wearable strain sensor is constructed for sensing and detecting human motions (e.g., subtle movement of mouth‐opening and large motion of joint‐bending), exhibiting a linear response with high sensitivity (gauge factor as high as 7.66) over 100–300% strain. This line of research will inspire renewed interest and work into synergic exploitation of nanospecies‐reinforced interactions and covalent crosslinks into the design of high‐performance composite materials.