A highly sensitive and multiplexed wireless sensing system with skin-like compliance and stretchability for wearable applications.

Wearable wireless sensing systems capable of monitoring critical biomarkers are increasingly valued for health monitoring and disease management. However, current systems often compromise on sensitivity, multi-parameter sensing capacity, compactness, power consumption, and wearing comfort, limiting their skin-interfaced applications. Here, we present a wireless, battery-free, multiplexed sensing system based on a high-order exceptional point (EP)-a singularity in non-Hermitian realm. This system features multiple distinct resonance frequencies that sensitively respond to physiological variations, exhibiting over 10-fold sensitivity improvement and 50% size reduction compared to conventional resonator-based systems. Moreover, the sensor employs a strain-resilient liquid metal composite and a soft substrate, ensuring wearing comfort, mechanical reliability, and antimicrobial properties. The effectiveness of this system is demonstrated through in situ monitoring of skin temperature and sweat electrolytes during exercise and prolonged monitoring of sweat glucose and ammonium in different subjects. The proposed system is highly transformative, offering benefits for various wearable applications.