A hierarchically designed nanocomposite hydrogel with multisensory capabilities towards wearable devices for human-body motion and glucose concentration detection

Abstract Hydrogels have shown great potential as flexible/wearable sensors, for detection of a variety of external stimuli. However, reports of sensors capable of detecting both electrochemical and mechanical stimuli are virtually non-existent. The current study employs nanostructured hierarchy, as a unique strategy towards development of hybrid hydrogel nanocomposites, for sensing human-body motion and glucose level in sweat. The nanocomposites comprise of a semi-interpenetrating polymer network where the nanometric level of hierarchy enables high conductivity, while the microscopic level imparts favorable electrochemical and mechanical properties. The hydrogels exhibit superior mechanical strength (up to 7.7 MPa) and toughness (up to 7.48 MJ m−3), one of the highest reported till date, in addition to good electrical conductivity (up to 0.14 S m−1) and electrochemical behaviour. The hydrogel-based prototype sensors could efficiently be used for successful detection of a multitude of human-body motion as well as glucose level determination with extraordinary sensitivity and minimal hysteresis. Additionally, the facile synthesis method of the hybrid hydrogel nanocomposites allows for low-cost fabrication and easy scalability of robust multifunctional sensors.