Breathable hydrogel keeps ECG signals steady through workouts and 10 days of wear‎

Hydrogels are squishy, biofriendly materials made mostly of water and a bit of polymer. The Jell-O-like substance is available in the form of medical patches, sprays and glues, and can be stuck to the skin or implanted in the body to dress wounds, affix implants, and encapsulate and release medicine over time.