Dental floss pick measures cortisol in real time

Chronic stress can lead to increased blood pressure and cardiovascular disease, decreased immune function, depression and anxiety, but the tools to monitor stress are often imprecise or expensive.

“It started in a collaboration with several departments across Tufts, examining how stress and other cognitive states affect problem solving and learning,” said Sameer Sonkusale, professor of electrical and computer engineering. “We didn’t want measurement to create an additional source of stress, so we thought, can we make a sensing device that becomes part of your day-to-day routine? Cortisol is a stress marker found in saliva, so flossing seemed like a natural fit to take a daily sample.”

Their design of a saliva-sensing dental floss looks just like a common dental floss pick, with the string stretched across two prongs extending from a flat plastic handle.

The saliva is picked up by capillary action through a very narrow channel in the floss. The fluid is drawn into the pick handle and an attached tab, where it spreads across electrodes that detect the cortisol.