A Highly Stretchable, Conductive, and Transparent Bioadhesive Hydrogel as a Flexible Sensor for Enhanced Real‐Time Human Health Monitoring

Abstract Real‐time continuous monitoring of non‐cognitive markers is crucial for the early detection and management of chronic conditions. Current diagnostic methods are often invasive and not suitable for at‐home monitoring. An elastic, adhesive, and biodegradable hydrogel‐based wearable sensor with superior accuracy and durability for monitoring real‐time human health is developed. Employing a supramolecular engineering strategy, a pseudo‐slide‐ring hydrogel is synthesized by combining polyacrylamide (pAAm), β‐cyclodextrin (β‐CD), and poly 2‐(acryloyloxy)ethyltrimethylammonium chloride (AETAc) bio ionic liquid (Bio‐IL). This novel approach decouples conflicting mechano–chemical effects arising from different molecular building blocks and provides a balance of mechanical toughness (1.1 × 10 6 Jm −3 ), flexibility, conductivity (≈0.29 S m −1 ), and tissue adhesion (≈27 kPa), along with rapid self‐healing and remarkable stretchability (≈3000%). Unlike traditional hydrogels, the one‐pot synthesis avoids chemical crosslinkers and metallic nanofillers, reducing cytotoxicity. While the pAAm provides mechanical strength, the formation of the pseudo‐slide‐ring structure ensures high stretchability and flexibility. Combining pAAm with β‐CD and pAETAc enhances biocompatibility and biodegradability, as confirmed by in vitro and in vivo studies. The hydrogel also offers transparency, passive‐cooling, ultraviolet (UV)‐shielding, and 3D printability, enhancing its practicality for everyday use. The engineered sensor demonstratesimproved efficiency, stability, and sensitivity in motion/haptic sensing, advancing real‐time human healthcare monitoring.