If you have ever had your blood drawn, whether to check your cholesterol, kidney function, hormone levels, blood sugar, or as part of a general checkup, you might have wondered why there is not an easier, less painful way.

Now there might be. A team of researchers from Caltech’s Cherng Department of Medical Engineering has unveiled a new wearable sensor that can detect in human sweat even minute levels of many common nutrients and biological compounds that can serve as indicators of human health.

The sensor technology was developed in the lab of Wei Gao, assistant professor of medical engineering, Heritage Medical Research Institute investigator, and Ronald and JoAnne Willens Scholar. For years, Gao’s research has focused on wearable sensors with medical applications, and this latest work represents the most precise and sensitive iteration yet.