The smartphone that just got smarter – by testing water and treating food

Phone cover prototype
© Bhaskar Mitra

A 24-year-old food scientist at the University of Copenhagen has developed a prototype that could potentially save millions of lives.

“I like doing crazy stuff.” Bhaskar Mitra, a 24-year-old food scientist at the University of Copenhagen, is describing a couple of his latest inventions. One is a bacon-flavored cracker – this is Denmark, after all – which changes color when dipped in sauce. I know, that deserves headlines of its own. But Mitra’s other idea has the potential to save millions of lives – because it’s a smartphone cover that can test water as well as test and treat contaminated liquid food.

Mitra, who’s from the Indian state of West Bengal, spent a year at his kitchen table tinkering with the prototype (illustrated above). The cover itself is just a chunky piece of cardboard (“Samsung Galaxy phones are bigger,” he insists). But it has two key components: a UV lamp and a blue filter to cover the lens.

The idea is simple: first, you scan your food using your smartphone’s camera, in near-darkness and under blue light, and then an app that Mitra has developed reveals anything that shouldn't be there – from impurities such as glass or sand to potentially dangerous microorganisms like listeria and cholera. Then you use the UV lamp to zap any bacteria. Scan your food again to determine if it’s safe to consume.

The science isn't new, of course. We’ve long used UV light to kill harmful microorganisms. “The tech was already there,” Mitra admits. The trick was making it in miniature, integrating it into a smartphone cover, and developing the app. And that combination of old and new technology excites him. “I wanted to create a link between a tangible and intangible product, and use this power to throw the magic around,” he says.

Mitra (above) didn't have a phone when he was growing up. Now, having seen what “all these fantastic apps” can do, he wants to exploit their potential in his field. “Food science is powerful in itself,” he says. “But if you can add anything interdisciplinary, it becomes twice as powerful, because now you have two approaches to solving a global problem.”

How effective is the prototype? “It gives you an idea that the food may be a lot safer,” Mitra says. “In certain cases, it kills the microorganisms – but it is difficult to gauge how much. But it definitely stops them multiplying.” He’s now running tests to see how long the UV light needs to be activated.

There are some wrinkles. The UV light must be used in the dark, and it eliminates only surface-level bacteria. In other words, it can decontaminate cutlery but not a chunk of cheddar. Even so, Mitra says, that still allows you to test for the presence of harmful bacteria in tap water, and to treat anything that’s been washed in potentially contaminated water. (Another bonus? The kit is solar-powered, meaning your phone can make emergency calls if it runs out of juice.)

Mitra says that if his invention ever makes it to market, it would cost around 300 DKK ($45 USD) and initially be used by travellers jetting off to exotic climes. His hope, of course, is that he can bring down the production cost and make it available in the developing world. West Bengal would top the list. “I had concern for people back home, so it was necessary for me to develop it,” he says.

For now, he’s focusing on his university fellowship and keeping an eye out for funding. But he intends to file for a patent in India, and remains hopeful that his invention will take off. “People only appreciate a good innovation if it solves a problem.” Unless it’s a bacon-flavoured cracker that changes color, that is.

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