A team of engineers at the University of California San Diego has created an electronic finger wrap that monitors vital chemical levels — such as glucose, vitamins and even drugs — directly from fingertip sweat.

Setting this wearable apart, the researchers added, is that the device is powered by the sweat that it analyzes.

Source: Shichao DingSource: Shichao Ding

According to its developers, those wearing the sweat-powered device, which fits around the wearer’s finger, can be monitored while they are at rest or asleep, and the device can continue to harvest energy from the wearer’s fingertip sweat.

The team selected the fingerprints because they are among the body’s most active sweat producers, featuring more than one thousand sweat glands each. Even without physical activity, the fingerprints produce an uninterrupted stream of perspiration.

To create the device, the researchers printed electronic components onto a thin, flexible and stretchable polymer that can be repeatedly bent, stretched and moved.

“It is based on a remarkable integration of energy harvesting and storage components, with multiple biosensors in a fluidic microchannel, along with the corresponding electronic controller, all at the fingertip,” the team added.

Enabling the device to operate are biofuel cells located at the point where the device encounters the fingertip. There, the biofuel cells collect and convert chemicals in sweat into electricity and this energy is subsequently stored in two stretchable silver chloride-zinc batteries that power four sensors. Each of those four sensors is designed to monitor a specific biomarker — glucose, vitamin C, lactate and levodopa, which is a drug used for treating Parkinson’s disease.

As the tiny paper microfluidic channels draw in the sweat, the device analyzes these biomarkers while simultaneously powering itself from the same sweat it samples. Meanwhile, a small chip processes the sensor data and then wirelessly transmits it using Bluetooth to a custom smartphone or laptop app.

The researchers suggest that the device can be customized to detect different sets of biomarkers tailored to individual health needs.

The study, “A fingertip-wearable microgrid system for autonomous energy management and metabolic monitoring,” has been published in the journal Nature Electronics.

To contact the author of this article, email mdonlon@globalspec.com