Soft yet Tough: a Mechanically and Functionally Tissue-like Organohydrogel for Sensitive Soft Electronics
Gehong Su, Yulin Zhang, Xueqian Zhang, Jinkui Feng, Jie Cao, Xinxing Zhang, Tao Zhou
Abstract
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.