Engineers at UC San Diego have developed an innovative sticker that can monitor vitamin C levels using fingertip sweat, offering a battery-free and convenient solution to track nutritional health.
A team of engineers at the University of California, San Diego has developed an innovative electronic sticker that can monitor an individual’s vitamin C levels using sweat from their fingertips. This breakthrough gadget, which attaches seamlessly to everyday items such as drinking cups, requires no blood draws, lab visits or batteries.
Caption: This battery-free electronic sticker attaches to everyday objects like a drinking cup and monitors vitamin C levels from a person’s fingertip sweat.
Credit: David Baillot/UC San Diego Jacobs School of Engineering
This flexible, adhesive polymer sheet collects trace amounts of sweat from a person’s fingertips as they hold a cup. Within mere minutes, the sticker harnesses enough power from the sweat to analyze it for vitamin C and wirelessly transmits the results to a nearby laptop via Bluetooth.
Published in the journal Biosensors and Bioelectronics, the new technology is a testament to the advancements in non-invasive health monitoring.
“By turning everyday objects like cups or bottles into smart sensors, people can gain real-time insights into their health and wellness without changing a thing about their daily routine,” co-senior author Patrick Mercier, a professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, said in a news release. “We’re moving toward a future of ‘unawareables’ — devices that are unobtrusive and essentially invisible so that you are unaware that you’re even using them. You just go about your day and your drinking cup can give you access to all this rich information.”
Tackling Global Health Challenges
Vitamin C is crucial for immune function, tissue repair and iron absorption, but current testing methods are cumbersome and costly, priced around $50 per test in the United States.
This new sticker offers a simpler, affordable and accessible alternative, especially in resource-limited settings.
“Most people only get a snapshot of their health once a year at the doctor. But our bodies change much more frequently than that,” Mercier added. “We want to make access to health data as frequent and effortless as holding your morning coffee cup or orange juice bottle.”
A Technological Marvel
The electronic sticker integrates screen-printed electronic components on a flexible sheet. A porous hydrogel pad collects sweat, and a built-in biofuel cell converts the sweat’s chemicals into electricity to power the sensor. The data collected on vitamin C levels is then transmitted via Bluetooth.
Fingertips are ideal for this kind of technology since they house over a thousand sweat glands, producing 100 to 1000 times more sweat than other parts of the body. This means the sticker can generate power even without physical exertion, making it practical for continuous use.
Low-Cost and Widely Accessible
The absence of a battery means the sticker is cost-effective, with potential production costs of just a few cents per unit. Its low cost could make it particularly impactful in developing regions, providing a critical tool for nutrition monitoring and health tracking.
“This is an elegant extension of our early fingertip sweat-based technology toward effortless, continuous monitoring of personal nutrition and health,” added co-senior author Joseph Wang, a professor in the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at the UC San Diego Jacobs School of Engineering.
Looking Forward
Future developments aim to extend the technology’s capabilities to measure other nutrients and biochemicals. The team envisions future iterations sending real-time data to smartphones or smartwatches, offering seamless health tracking throughout the day.