Ultrahigh\nStretchable,\nHighly Transparent, Self-Adhesive,\nand Environment-Tolerant Chitin Nanocrystals Engineered Eutectogels\ntoward Multisignal Sensors

Addressing\nthe conflict between achieving elevated mechanical\nstretchability\nand environmental adaptability is significant to a breakthrough in\nthe practical application of flexible wearable materials. Therefore,\ninspired by the perceptive and protective properties of human skin,\nflexible wearable electronic skins (E-skins) based on deep eutectic\nsolvent (DES) liquid and multiresponse eutectogel have been widely\nconsidered to be a promising platform for building a flexible wearable\nmanagement system to achieve the purpose of “one stone, two\nbirds”. In this work, a multifunctional E-skin was designed\nbased on an ultrastretchable, transparent, self-adhesive, and environmentally\ntolerant eutectogel by first incorporating cationized modified chitin\nnanocrystals into a covalently cross-linked polymer network comprised\nof the skeleton formed by a PAA polymerization network structure serving\nas a stretchable matrix and filled with DESs (ChCl:EG). The obtained\neutectogel exhibits superhigh stretchability (up to 6707%), high toughness\n(17.7 MJ/m<sup>3</sup>), mechanical strength (0.48 MPa), self-adhesive,\nand high transparency (91.2%). Simultaneously, the multisignal sensor\nbased on the above comprehensive properties and thermosensitive capacity\nexhibits a wide monitoring range, high strain/compression/temperature\nsensitivity, and good reproducibility. Remarkably, the sensor could\nbe attached to rat hearts without glue or stickers for long-term monitoring\nof high-quality in vivo heartbeat signals. In this way, it is believed\nthat the designed E-skin system based on eutectogel has great potential\nto serve as a promising platform for the next generation of flexible\nmultisignal monitoring integrated wearable management systems.