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Thirsty? This Color-Changing Textile Coating Can Tell

SOAK by Erik post-workout

As with most things in life, there’s more to sweat than meets the eye.

Dutch design researcher Paulien Routs has developed a sweat-sensitive textile coating that can be applied to workout wear to indicate the wearer’s hydration levels.

“At a time when so much information is coming at us via screens, data and online profiles, I think it’s easy to get out of touch with our senses,” explained Routs, who spent about eight months working on the coating with cosmetic chemistry lab Thewa Innovations, aesthetic doctor Annebeth Kroeskop and the Dutch Cosmetics Association.

“I wanted to create an interaction between a wearer and his body that offers insight into the status of his health in a way that’s an extension of the body’s natural signals,” she said, adding, “Once I knew how to make a sweat-sensitive, color-changing textile coating from natural ingredients, like rose petals and turmeric, I continued working on a stronger prototype that could react in a range of colors.”

Here’s how it works: As the wearer sweats, the textile coating—which is applied to clothing before a workout and comes out when it’s washed—reacts to the levels of basicity and acidity present in the moisture and changes color accordingly. If it turns blue, the wearer is well-hydrated with a high level of base fluids. Green is good, too. Yellow to brown, on the other hand, means dehydration.

hydrated body

“It creates a quantified-self that’s focused on body-centered results rather than numbers that make you compete with others or yourself,” she noted.

When she tested the coating on people with different diets, someone who drank four glasses of water before a 10K run came back with a blue shirt, whereas someone who drank one glass of orange juice and no water stained their shirt yellow.

Though not currently available commercially, Routs is exploring different applications for Soak and how it can support sports or improve health.