Sweat-Powered Wearables: Health Monitoring at Your Fingertips, Literally

1 Big Thing: Researchers at the University of California, San Diego, have developed a sweat-powered device wearable as a finger wrap that provides continuous health monitoring without the need for batteries.

Why It Matters: This technology could revolutionize how we monitor chronic conditions and personal health, making it easier and more accessible for everyone.

Between the Lines: The wearable uses sweat from your fingertip as a power source, turning a small amount of natural perspiration into a reliable, sustainable energy source. “This is automatic health monitoring at your fingertips,” said Shichao Ding, a postdoctoral researcher in the research group. The potential for this technology to change the way we approach health tracking is immense. The sweat-powered finger wrap  monitors levels of glucose, lactate, vitamin C and levodopa in that same sweat.

Go deeper

How Does It Work?

Developed by engineers at the University of California, San Diego, this wearable device is designed to fit around your fingertip, where it continuously collects sweat. The device is constructed from several electronic components printed onto a thin, flexible, and stretchable polymer material, allowing it to conform to the finger while being durable enough to withstand repeated bending, stretching, and movement .

Even when you’re at rest or asleep, your fingertips produce enough sweat to power the device. It uses biofuel cells, positioned where the device contacts the fingertip, to efficiently collect and convert chemicals in sweat, such as lactate and glucose, into electricity. This electricity is stored in a pair of stretchable, silver chloride-zinc batteries, which power a suite of sensors .

“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,” explained Joseph Wang, a professor at UC San Diego .

Why Fingertips?

Fingertips are surprisingly prolific sweat producers, even without physical activity. Each fingertip has thousands of sweat glands, making them ideal for generating the small but steady flow of sweat needed to power the device. According to the researchers, the device can even operate during periods of inactivity, making it a reliable tool for continuous health monitoring. “The wearer can be resting or asleep, and the device can still harvest energy and track biomarker levels,” said Shichao Ding .

What Does It Monitor?

The device is equipped with four sensors, each designed to monitor a specific biomarker: glucose, vitamin C, lactate, and levodopa, a drug used for treating Parkinson’s disease. As sweat is wicked through tiny paper microfluidic channels to these sensors, the device analyzes the biomarker levels, all while drawing the energy it needs from the very sweat it’s sampling .

Real-World Testing

During testing, a subject wore the device throughout the day to track various health metrics. For instance, it monitored glucose levels during meals, lactate levels during both desk work and exercise, vitamin C levels while drinking orange juice, and levodopa levels after eating fava beans, a natural source of the compound . The data collected by the sensors was processed by a small chip and transmitted wirelessly via Bluetooth to a custom-designed smartphone or laptop application.

Personalized Health Monitoring

The device not only tracks your body’s chemistry but also sends data wirelessly to a smartphone or laptop. This means that you can receive real-time health updates throughout the day, whether you’re exercising, resting, or even sleeping. The team is also exploring the possibility of creating a closed-loop system. The system could potentially administer treatments, like insulin for diabetes, based on the data it collects.

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

Future Potential

Imagine a world where your wearable device can detect when your blood sugar is low and automatically administer insulin. Or one that alerts you if you’re deficient in vitamins and suggests dietary changes. This is the future that sweat-powered wearables are inching towards.

‍

References

Original Article: Liezel Labios , UC San Diego Today - Finger Wrap Uses Sweat To Provide Health Monitoring at Your Fingertips—Literally

Paper: “A fingertip wearable microgrid system for autonomous energy management and metabolic monitoring.” Co-authors include Tamoghna Saha*, Lu Yin*, Ruxiao Liu, Muhammad Inam Khan, An-Yi Chang, Hyungjin Lee, Han Zhao, Yuanzhe Liu, Ariane Sina Nazemi, Jiachi Zhou, Chuanrui Chen, Zhengxing Li, Chenyang Zhang, Sara Earney, Selene Tang, Omeed Djassemi, Xiangjun Chen, Muyang Lin, Samar S. Sandhu, Jong-Min Moon, Chochanon Moonla, Ponnusamy Nandhakumar, Kuldeep Mahato and Sheng Xu, UC San Diego; and Youngmin Park, Samsung Electronics, Republic of Korea.

Photo Credit: Shichao Ding