Microneedle patch offers painless way to track health without drawing blood

Getting your blood drawn can be uncomfortable. Yet for decades, it’s been the go-to method for checking what’s happening inside your body. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill have now created a painless and self-powered alternative: a microneedle patch that monitors health without drawing blood—or needing batteries.

Published in the journal, Lab on a Chip, this new patch samples a clear body fluid called dermal interstitial fluid, or ISF. It’s the liquid that fills the spaces between your skin cells. What’s exciting is that ISF holds almost all the same health clues that blood does, like stress, hormone, and hydration markers. But unlike blood, ISF doesn’t need to be spun or processed before being tested.

“Biomarkers are measurable indicators of biological processes, which can help us monitor health and diagnose medical conditions,” says Dr. Michael Daniele, who led the study. The idea was to create a simpler, more comfortable, and cheaper way to track these biomarkers in real time.

Instead of drawing blood, the patch collects tiny samples of ISF just beneath your outer layer of skin. This patch doesn’t need any outside power source. It’s fully passive—meaning it works on its own, quietly gathering important information about your body.

At first glance, the patch might not look very different from a bandage. But the real magic happens inside its four layers.

The outermost part—the housing—is a thin layer of polymer. Underneath sits a special gel loaded with glycerol. Next comes a paper strip. Finally, at the base are the microneedles, which are so small they don’t cause pain when applied.

These tiny needles are made of a material that swells when it touches ISF. Once applied to the skin, the microneedles start drawing in the fluid. It moves upward, much like how a paper towel absorbs water. The ISF first fills the paper layer, which stores the sample. Then the glycerol-rich gel creates osmotic pressure. This pulls in even more ISF through the paper until it’s fully saturated.

“The paper is where the ISF is stored,” says Daniele. “When you take the patch off, you remove the paper strip and analyze the sample.”

It’s a smart and energy-efficient system. There are no electronics, no power buttons, and no wires involved. Once you peel off the patch, the paper can be quickly tested in a lab or read using a small device.

Before testing on humans, the team used synthetic skin to check how well the patch worked. The results were impressive. In some cases, it took just 15 minutes to collect enough fluid to analyze. And once the fluid was stored in the paper, it remained usable for at least 24 hours.

For this test, researchers focused on cortisol—a hormone linked to stress. Cortisol levels change throughout the day, making it ideal for continuous monitoring. That’s something blood tests struggle to do without becoming inconvenient or painful.

“Cortisol is something people may want to monitor multiple times a day without having to draw blood repeatedly,” Daniele says.

Since ISF shares most biomarkers found in blood, this opens the door for the patch to track a wide range of other health indicators. These could include glucose, lactate, or even signs of inflammation. Future versions might even help detect early stages of illness before symptoms appear.

The team has already started testing the patch on human subjects and continues to develop companion tools to interpret the data easily.

One of the most exciting parts of this development is its potential to reduce costs. Right now, blood tests require trained personnel, syringes, vials, and a lab. Each of these adds to the total price of care—not to mention the discomfort.

Daniele believes the microneedle patch could offer a less expensive, more flexible alternative. The materials used are common and inexpensive. While the microneedles are the most complex part to produce, they may still cost less than the supplies and labor needed for a standard blood draw.

“The highest cost of the patches would be manufacturing the microneedles, but we think the price would be competitive with the costs associated with blood testing,” he says.

Another major benefit? Comfort. For people who dislike needles—or who need to be monitored often—the patch could make a big difference. It’s easy to apply, painless to wear, and can collect valuable data without interrupting daily life.

The team is also working on a reader device that makes analyzing the paper strip even easier. So far, they’ve developed a sensor that reads cortisol levels from the patch. A second device focused on a different biomarker is already in progress.

Daniele and his team are now looking for industry partners to help scale up production and explore more applications.

“We’d love to talk with companies in the diagnostic space to explore additional applications, and we’d also like to talk with potential partners about scaling up production,” he says.

This patch could change how people think about health tracking. Instead of visiting a lab, you might monitor key health signals right at home. Athletes could track performance-related biomarkers during training. Patients with chronic illness might stay on top of their condition with just a few daily patches.

Beyond medicine, this technology could make a mark in areas like sports science, mental health, and even astronaut health in space.

And since the device stores data in a paper strip, it allows for simple offline analysis. No internet connection or complex tech is required. That could make it useful in rural or low-resource settings, where traditional lab access is limited.

This microneedle patch isn’t just a step forward in wearable tech. It’s a leap toward pain-free, real-time health monitoring that works for almost anyone, anywhere.

With continued testing and support from industry, this small patch could become a powerful new tool in healthcare—and beyond.

Note: The article above provided above by The Brighter Side of News.

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