Researchers invent waterproof patch to monitor UV ray exposure

How much sun exposure is enough?

Andrea Armani, holder of the Fluor Early Career Chair in Engineering and graduate researcher Michele Lee of the USC Viterbi School of Engineering have developed a color-changing patch that can notify users of exposure to ultraviolet rays.

A person wearing the transparent, flexible 0.5” by 0.5”-sized patch is notified of total UV exposure by a change in color. When the patch turns orange, the user has reached the daily dose of Vitamin D recommended by the World Health Organization.

Because the flexible patch is less than half a millimeter thick, it’s ideal for anyone who spends a lot of time under the sun.

Unlike apps on the iPhone or Samsung watch, the patch does not require a power source.

“It’s like a Band-Aid,” Armani said. “Wear it … throw it away.”

The patches created by the Armani Lab work when wet and will function and adjust their responses when sunscreen is applied — they can be stored for a period of up to five weeks.

The patches are made of material patented by Armani and Lee and were constructed of FDA-approved non-toxic polymers for human use.

The research is documented in the journal ACS Sensors.

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