Scientists develop a wearable UV sensor from light-sensitive squid pigment

A team from Northeastern University have created a dime-sized UV (ultraviolet light) detection sticker from a study into the colour-changing ways of camouflaging squid. Over the last decade there have been numerous technological advancements designed to reduce incidences of skin cancer due to UV exposure: a serendipitous discovery was made when Northeastern scientists noticed a particular squid pigment molecule, xanthommatin, changed its colour upon UV exposure.

“When we noticed it changed colour in light, we were super annoyed,” said Leila Deravi, assistant professor of chemistry and chemical biology at Northeastern University.

Professor Deravi and colleagues then designed a device using the colour-changing pigment. The device comprises of five layers of thin plastic, along with a round piece of paper treated with the pigment and then dried out.

A “button” integrated into the device releases fluid from a small reservoir on its edge – the fluid travels through channels cut into the plastic and hydrates the treated paper to activate it. The treated paper shifts from yellow/orange to red the more UV it is exposed to.

The device was found to work well in different conditions akin to UV exposure that people are likely to experience daily, even when coated with sunscreen, whereby it changed colour much more slowly.

“We all know that too much sun on a high-UV-index day is bad. But we don’t necessarily know how that translates to time in the sun,” said research scientist Dan Wilson from the Kostas Research Institute, Northeastern University. “This is meant to provide a visual, qualitative indication of when you may have been in the sun for too long and you should consider spending some time in the shade or reapplying your sunscreen.”

The scientists expect that people will use this device to monitor sun exposure, but it could also be used in other situations where there’s utility to measuring light exposure. For example, UV radiation is often used to sterilise environments. Professor Deravi said the stickers could be used to indicate when a surface has been exposed to UV radiation for long enough to be fully sterilised.

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Category: Features, Technology & Devices