Gatorade’s efforts to conquer dehydration have again entered the digital realm. Twice reports that the sports drink company and Northwestern University have developed a low-cost wearable skin patch that displays various colors to conveniently let the wearer know when they need to take a drink.

The patches were developed and introduced in 2016 by Northwestern University McCormick School of Engineering professor John A. Rogers, who told Twice that the devices could make their way to retail within a year, and potentially at a price point of just $3. These patches, which were also profiled last month by Northwestern University’s communications publication, Northwestern Now, can measure chloride loss, glucose, lactate, pH levels, and concentrations of heavy metals in the wearer’s sweat.

“The devices from a year ago could determine the average chloride concentration during an exercise period,” Rogers said in Northwestern Now. “But now we have devices that fill sequentially in time. This is important because variations in sweat biomarkers give a sense of fatigue level as you’re exercising. We didn’t have that capability previously.”

A key component of the patches is that an athlete does not need to stop their workout to read their information. As sweat works its way into the patch’s compartments, reactions with chemical reagents create noticeable color changes that correlate with different sweat concentrations. While this can give wearers an easy indication of when they need to hydrate, athletes could also use their smartphone’s camera to receive more detailed information about their current condition, according to Twice.

Northwestern highlighted the partnership between Rogers and Gatorade last month, as well as others with the Seattle Mariners, the US Air Force, and the Shirley Ryan AbilityLab to further test and develop the skin patch. The patches are also actively being used by the university’s men’s swimming and diving team, who are able wear them in the water to gauge their hydration.

“Our mission at the Gatorade Sports Science Institute has always been to help athletes optimize their health and performance through research and education in hydration and sports science,” Lindsay Baker, principal scientist at the Gatorade Sports Science Institute, said in Northwestern Now. “Through our partnership with Epicore Biosystems [a Cambridge, Massachusetts-based spinoff of Rogers’ lab focused on the patches], we’re developing exciting new ways to measure and monitor sweat, which can help us better recommend hydration strategies for our athletes.” 

Gatorade is no stranger to skin patches and smart devices. At SXSW in 2016, the company touted a smartphone-connected water (or Gatorade) bottle cap that, along with an adhesive patch, tracks the user’s fluid intake and sodium loss. The bottle cap would also light up when a user needed to drink more, and send data to a connected smartphone app for additional analysis and viewing.

Just months prior to this, another consumer brand, L’Oreal, had announced at CES that is would be working on a wearable, smartphone-connected skin patch that monitor’s a user’s UV exposure.

Rogers, for his part, hasn’t limited his adhesive patch research to sweat alone. Just last month, he and Northwestern detailed a connected sensor patch developed in conjunction with the Shirley Ryan AbilityLab that could allow clinicians to better monitor stroke patients recovering at home.