Wearable strain sensors for human motion detection and health monitoring based on hybrid graphite-textile flexible electrodes

Facile and inexpensive assembly of graphite coatings through pencil drawing method has become a fascination for variety of electronic and optoelectronic applications. Here, we report the successful assembly of graphite coatings on flexible and stretchable textiles for the fabrication of electronic devices. Graphite pencils are used for directly coating the graphite on commercial textiles through drawing method. The graphite-coated textiles are used as electrodes for the fabrication of stretchable multifunctional sensors. A fruitful pre-strain strategy is used for assembly of graphite coatings which not only can tune the sensitivity of sensors, but also increases the resistance stability of devices. The fabricated sensor is used for human motion detection and health monitoring; it efficiently detects the strains provided by human organs during their movements, and being multifunctional, adeptly senses the changes in humidity and human sweating, notices the changes in temperature and responds to changes in light concentration. The sensor can work soundly for uniaxially applied strain up to 50% and multiaxially up to 50 × 50%, it is washable, low-cost, possessed a stable response, worked proficiently for 5000 stretching cycles, delivered a markable sensitivity of 3247 for applied strain 50%, and offered a response time of 0.11 s.