Soft yet Tough: a Mechanically and Functionally Tissue-like Organohydrogel for Sensitive Soft Electronics

Human soft tissues like skins and muscles possess uniquely soft yet tough and tear-resistant mechanical features and sophisticated functionality, which is still challenging to mimic in artificial materials. Herein, we report a mechanically and functionally tissue-like organohydrogel by constructing abundant sacrificial bonds (hydrogen bonds) between a soft hydrogel matrix and glycerol (Gly) via a facile solvent displacement strategy. By regulating the Gly content, the optimized organohydrogel exhibited remarkable mechanical properties that fully match human soft tissues, including the distinct soft (∼128 kPa in Young's modulus) yet tough (∼15.66 MJ m–3 in toughness), and tear-resistant (∼13.99 kJ m–2 in fracture energy) features. Meanwhile, the gel is strong (∼1.35 MPa in tensile and ∼23.1 MPa in compression) and ultrastretchable (∼2150%). Furthermore, the organohydrogel possesses a wide spectrum of tissue-like functionalities, including freezing/heating tolerance, self-healing, electroconductivity, and multiple sensations (tensile, pressure, temperature, and solar flux). By taking these advantages, proof-of-concept applications in personal healthcare monitoring, anti-counterfeiting, and soft electronic skins were demonstrated using the PAAN/Gly organohydrogel. We anticipated that this work would open an avenue toward developing soft materials with sophisticated mechanical properties and functionalities resembling human tissues.