“…More in deep, graphene, conductive polymers, CNTs, nickel, and copper metal nanoparticles have been utilized as thermal sensing element. [51][52][53][54] For flexible wearable sensors, utilizing a flexible substrate is necessary in order to impart stability to the active material. In this respect, polyurethane, PDMS, polyethylene terephthalate, Ecoflex, and polyethylene naphthalate are the most commonly used flexible substrate in wearable sensors for health monitoring.…”