Adhesive,\nStretchable, and Transparent Organohydrogels\nfor Antifreezing, Antidrying, and Sensitive Ionic Skins

Abstract

As a flexible wearable device, hydrogel-based\nsensors have attracted\nwidespread attention in soft electronics. However, the application\nof traditional hydrogels at extreme temperatures or for a long-term\nstability still remain a challenge because of the existence of water.\nHerein, we reported an antifreezing and antidrying organohydrogel\nwith high transparency (over 85% transmittance), high stretchability\n(up to 1200%), and robust adhesiveness to various substrates, which\nconsist of polyacrylic acid, gelatin, AlCl³⁺, and tannic\nacid in a water/glycerin binary solvent as the dispersion medium.\nAs the binary solvent easily forms strong hydrogen bonds with water\nmolecules, organohydrogels exhibited excellent tolerance for drying\nand freezing. The organohydrogels maintained conductivity, adhesion,\nand stable sensitivity after a long-term storage or at subzero temperature\n(−14 °C). Moreover, the organohydrogel-based wearable\nsensors with a gauge factor of 2.5 (strain, 0–100%) could detect\nboth large-scale movements and subtle motions. Therefore, the multifunctional\norganohydrogel-wearable sensors with antifreezing and antidrying properties\nhave promising potential for human–machine interfaces and healthcare\nmonitoring under a broad range of environmental conditions.