Danny Weber
UC San Diego researchers built a prototype ring that measures up to four of six biomarkers without exercise-induced sweating.
Engineers at the University of California San Diego have created a prototype smart ring for continuous biochemical monitoring. The device analyzes sweat from the surface of a finger and can simultaneously track up to four of six biomarkers: glucose, ketones, vitamin C, uric acid, lactate and alcohol. The study was published on July 23, 2026, in Nature Communications.
No exercise or deliberate sweating is required. A built-in osmotic hydrogel creates a pressure gradient and painlessly draws a small amount of fluid through the skin. Electrochemical sensors then determine the concentration of the selected substances, while the results are sent wirelessly to a smartphone app.
In tests involving healthy volunteers and people with type 1 diabetes, glucose readings closely matched commercial continuous glucose monitoring systems, while ketone measurements aligned with portable blood analyzers. The authors say tracking both markers at once could eventually help refine insulin dosing, but the ring remains a research prototype and is not intended for independent medical decisions.
The prototype contains a sensor array, a sweat microchannel, low-power electronics and a flexible rechargeable zinc–silver oxide battery. A single charge provides about 12 hours of continuous operation, and individual sensor calibration remained stable for roughly two months. Its polymer housing is 3D-printed and still considerably bulkier than ordinary smart rings.
Unlike most commercial wearables, which mainly track physical signals such as heart rate, temperature, activity and sleep, the new design adds molecular sensing. That could significantly broaden what wearable devices can monitor, although researchers still need to shrink the ring, improve battery life and confirm its accuracy in larger studies.
© A. Krivonosov