Hydrogen-bonding-assisted toughening of hierarchical carboxymethyl cellulose hydrogels for biomechanical sensing

Herein we present a CMC based hydrogel that can be engineered for texture by applying a soaking strategy after freeze-thaw. These two processes lead to a hierarchal structure within the CMC polymer hydrogels. Such hydrogels can be strain hardening; that is the gel modulus increases with higher strain levels. Both the failure stress and energy are high (1.54 MPa and 9.94 kJm(-2) respectively). At sub-failure strains, the hydrogels show a high degree of recoverability as evidenced by their minimal hysteresis in a stress-strain test. Furthermore, these hydrogels are electrically conductive making them good candidates for tough sensors and wearable electronic devices.

Automated summary

The CMC-based hydrogel presented here has a hierarchical structure and strain hardening properties, with high failure stress and energy, as well as high recoverability in strain tests. Additionally, these hydrogels are electrically conductive, making them suitable for sensors and wearable electronic devices.