Imagine continuous, personalized health monitoring being as simple as wearing a Band-Aid. Engineers at the University of California San Diego have developed an innovative electronic finger wrap that could make this a reality. This groundbreaking device monitors vital chemical levels—such as glucose, vitamins, and even drugs—by analyzing the same fingertip sweat from which it draws its power.

Figure 1. The Finger Wrap. (Credit: Shichao Ding)

The research, led by Professor Joseph Wang and published on September 3 in Nature Electronics, introduces a device that snugly wraps around the finger and utilizes fingertip sweat as its power source. Despite their small size, fingertips are packed with over a thousand sweat glands and can produce up to 1000 times more sweat than most other areas of the body, even at rest [1]. This steady trickle of perspiration provides a constant energy source, allowing the device to function even during inactivity or sleep. Figure 1 shows the finger wrap is powered by the wearer's fingertip sweat—and also monitors levels of glucose, lactate, vitamin C and levodopa in that same sweat.

Crafted from flexible, stretchable polymer material, the device integrates multiple electronic components, enabling it to conform to the finger while withstanding repeated bending and movement. “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,” said Wang [2].

The device’s operation centers around biofuel cells positioned at the fingertip. These cells efficiently convert sweat chemicals into electricity, which is then stored in a pair of stretchable, silver chloride-zinc batteries. These batteries power four sensors, each designed to monitor specific biomarkers: glucose, vitamin C, lactate, and levodopa (a Parkinson’s disease treatment drug). As sweat moves through tiny paper microfluidic channels to these sensors, the device analyzes the biomarker levels while simultaneously powering itself from the same sweat it samples. The data is processed by a small chip and transmitted wirelessly via Bluetooth to a custom smartphone or laptop application.

“This is automatic health monitoring at your fingertips,” said Shichao Ding, a postdoctoral researcher and co-first author of the study. “The wearer can be resting or asleep, and the device can still harvest energy and track biomarker levels.”

In tests, a subject wore the device throughout the day, tracking glucose levels during meals, lactate levels during work and exercise, vitamin C levels while drinking orange juice, and levodopa levels after consuming fava beans, a natural source of the compound.

The device is customizable, allowing researchers to tailor it to detect different biomarkers for individual health needs. The team is also working on a closed-loop system that could not only monitor biomarkers but also administer treatments based on the collected data. For example, a diabetes patient could benefit from a device that continuously monitors glucose levels, automatically delivers insulin as needed, and then assesses the treatment’s effectiveness by further monitoring biomarker levels.

“Autonomous power, sensing, and treatment all in one device—that’s the ultimate goal,” said Ding.

Source: UC San Diego

References:

1. https://www.eurekalert.org/news-releases/1056252
2. https://www.cbs19news.com/news/health/new-wearable-device-uses-sweat-to-monitor-your-health/article_a3c1051c-1c45-55f3-91db-869d55c0db76.html

Cite this article:

Hana M (2024), Sweat-Powered Wearable Could Revolutionize Personalized Health Monitoring, AnaTechmaz, pp. 282