(Invited) Contact-Free, Wireless Wearable Physiological Sensors Based on Plasmonic Metamaterials

Wearable sensors offer a promising avenue for tracking disease progression and delivering care outside traditional clinical settings. However, existing wearable sensors require strongly adherent interfaces to the skin for continuous physiological monitoring. In this work, we propose a novel approach that introduces compact, flexible, wireless sensors capable of continuous physiological signal monitoring without the need for direct skin contact. Our sensing device integrates a wireless sensing component, a 24-GHz transceiver, and a microcontroller unit on a flexible printed circuit board. The wireless sensing mechanism allows these sensors to be placed without any physical contact to the body, including on eyewear, clothing, and wristbands. Experimental results demonstrate the effectiveness of these non-contact sensors in accurately monitoring vital signs, including heartbeat, respiration, wrist pulse, and temporal pulse.