AN ULTRA-HIGH SENSITIVE WEARABLE STRAIN SENSOR BASED ON POLYHEDRAL STRUCTURED N-CO3O4 COATED LASER-INDUCED GRAPHENE

We newly proposed a piezoresistive strain sensor based on polyhedral structured nanoporous cobalt oxide (N-Co3O4) nanoparticles coated laser-induced graphene (LIG) for smart wearable electronics. Exploiting the physiochemical properties of LIG and N-Co3O4, a strain sensor with outstanding sensitivity and stability were proposed and demonstrated. The fabricated sensor exhibited ultra-high sensitivity of 1177 and 39548 in low (0 to 18%) and high (18 to 23%) strain range, respectively. It also showed an ultra-low detection limit of 0.025% and excellent stability over 10,000 cycles. Finally, we have successfully exploited the sensor's performance for wearable healthcare applications such as subtle deformation (e.g., wrist pulse) induced from the human body to large finger bending motion.