A Customisable Wearable Saliva Sensing Platform

Principle Investigator: 
Prof. YAN Feng, Associate Director, Research Institute for Intelligent Wearable Systems; Chair Professor of Organic Electronics, Department of Applied Physics

This personalised, comfortable, saliva sensing platform integrates multi-gate organic electrochemical transistors, a wireless circuit, an ultrathin battery and a wearable substrate designed for intraoral use. Positioned near the sublingual glands, it ensures direct detection of fresh saliva, enabling real-time, continuous monitoring of critical biomarkers such as glucose, uric acid and lactate.

The platform effectively records dynamic changes in these metabolites during daily activities such as eating, drinking, running and working. Clinically, it has achieved accurate glucose monitoring, showing a strong positive correlation (90%) between fasting saliva and blood glucose levels in 500 subjects, including both diabetic and healthy individuals. This suggests that saliva glucose levels can non-invasively estimate fasting blood glucose.

The ability of the platform to track glucose variations in both saliva and blood offers a promising approach to non-invasive continuous glucose monitoring, marking a significant advancement in wearable sensors for personalised healthcare.