Engineers at the University of California, Berkeley—in collaboration with colleagues at Taiwan’s National Chiao Tung University—have developed 3D printing technology that includes electrical components and sensors. The engineers put the new technology to the test by creating a wireless “smart cap” for milk that detects signs of spoilage.

“This 3D-printing technology could eventually make electronic circuits cheap enough to be added to packaging to provide food safety alerts for consumers,” said senior author Liwei Lin, professor of mechanical engineering via Berkeley News. “You could imagine a scenario where you can use your cellphone to check the freshness of food while it’s still on the store shelves.”