High-Strength, Freeze-Resistant, Recyclable, and Biodegradable Polyvinyl Alcohol/Glycol/Wheat Protein Complex Organohydrogel for Wearable Sensing Devices

The application of flexible wearable sensing devicesbased on conductivehydrogels in human motion signal monitoring has been widely studied.However, conventional conductive hydrogels contain a large amountof water, resulting in poor mechanical properties and limiting theirapplication in harsh environments. Here, a simple one-pot method forpreparing conductive hydrogels is proposed, that is, polyvinyl alcohol(PVA), wheat protein (WP), and lithium chloride (LiCl) are dissolvedin an ethylene glycol (EG)/water binary solvent. The obtained PVA/EG/WP(PEW) conductive organohydrogel has good mechanical properties, andits tensile strength and elongation at break reach 1.19 MPa and 531%,respectively, which can withstand a load of more than 6000 times itsown weight without breaking. The binary solvent system composed ofEG/water endows the hydrogel with good frost resistance and waterretention. PEW organohydrogel as a wearable strain sensor also hasgood strain sensitivity (GF = 2.36), which can be used to detect themovement and physiological activity signals in different parts ofthe human body. In addition, PEW organohydrogels exhibit good degradability,reducing the environmental footprint of the flexible sensors afterdisposal. This research provides a new and viable way to prepare anew generation of environmentally friendly sensors.