There's Now a Wearable Sensor That Tells You When It's Time for a Drink -- What It Uses Might Make You Cringe a Little, But...

Whether it's walking to work, pushing the kid's stroller or just playing in the sand, summer activities all share one common risk.

Sandia National Laboratories researcher Ronen Polsky holds a prototype of a microneedle fluidic chip device able to selectively detect and painlessly measure electrolytes in the fluids around skin cells (Image source: Sandia National Labs)

They can leave you dehydrated.

But Sandia National Laboratories has a unique monitoring device that can warn you if your hydration levels are running low, and it can be worn like a watch. Engadget reports:

"An array of micro-needles on the underside of the watch-like device sticks into your skin to measure your interstitial fluid levels -- broadly speaking, the water that sits between your cells. Whenever this figure falls below the safe limit, you'll be alerted to go hit the bar, a technology that could revolutionize sports and military science, as well as help monitor patients in hospitals."

Yep. You read that right. It uses needles.

They act like mini syringes that only sample interstitial fluid — the liquid between skin cells, so the device can be used over and over again to measure whether your body has the correct balance of water to electrolytes.

Nearly everything you do during the day — walking, talking, typing and even eating — requires energy. That energy, in turn, generates heat, which escapes the body through perspiration. Perspiration is the mechanism that keeps the body cool, and during the summer, your body works overtime to regulate your internal temperature.

Though anything that uses needles doesn't sound like something you want to wear, the engineers designed the sensor to be pain-free by employing microneedles so tiny they won't traumatize the nerves when pressed into the skin, Eurekalert reports.

"This is the future of personalized health care,"Ronen Polsky, Sandia National Laboratories researcher, said. "These wearable technologies are just starting to come out in different forms. It's inevitable that people will go there."

The nine sampling needles, each only 800 millionths of a meter (microns) in height, sit just above a fluidic channel that draws the interstitial fluid over nine gold disk electrodes. Each disk can be tailored to detect a different analyte.

"We're proposing a minimally invasive way to move away from centralized laboratory testing," Polsky said.

Don't think you need it?

Consider this: most adults lose about 1.5 liters of fluid a day in urine, and another entire liter is lost through breathing, sweating and bowel movements. An average woman needs about 11 cups of water (2.7 liters) — from all beverages and foods — each day, and the average man needs about 15.5 cups (3.7 liters), according to 2004 recommendations from the Institute of Medicine.

Eventually the researchers envision a "sense-respond" device where some needles can read electrolytes while other needles, on demand, send electrolytes to make up for deficiencies, according Sandia Labs. The device, when commercially available, could decrease the time ordinary citizens, athletes and the military must spend in emergency rooms, lab testing facilities or doctors' offices.

"Investors have expressed interest in commercial applications for the technology in healthcare and sports medicine, among other areas," Polsky said.

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(H/T: Engadget)

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