The wearables market’s tremendous growth during the past decade continues to drive research and innovation. In its report Wearables Sensors 2021-2031, IDTechEx predicts that the annual market for sensors used in wearables will be greater than $5 billion by 2025. Some of this growth will come from novel sensors that are still under development. Northeastern University Kostas Research Institute scientist Dan Wilson’s recent work with a UV-sensitive squid pigment is an example of an accidental discovery uncovered while working on a different project.

Wilson’s serendipitous discovery happened when he was part of a team studying how cephalopods such as squid and octopus hide in plain sight with camouflage. The team was working in the Biomaterials Design Group led by Leila Deravi, assistant professor of chemistry and chemical biology at Northeastern. In the course of his research, Wilson discovered that the pigment xanthommatin provides visible color in the squid’s bag of camouflage tricks. Initial plans to explore ways to adapt the pigment’s color-changing capability for consumer applications didn’t pan out. Wilson found that xanthommatin wasn’t stable and would change color in ambient natural light. Wilson then made the leap to consider xanthommatin as a sensor to detect UV overexposure.

Wilson used former experience with microfluidics to design a UV detector. Wilson puts a small piece of dried-out paper previously treated with xanthommatin in the middle of four layers of clear plastic sheets. A wearer activates the sensor by pressing on the edge of the button-like device to release fluid that hydrates the paper. With successive UV exposure the paper changes from yellowish orange to red. Wilson describes his work testing xanthommatin-treated for different levels of UV exposure in a paper in ACS Sensors. Similar to 3M’s accidental development of the adhesive that make Post-It notes stick temporarily when the company was trying to find a tough, permanent adhesive, Wilson’s UV sensor discovery stems from seeing opportunity in failure.