Engineers at Penn State University have developed a paint-on electronic tattoo made from conductive ink that can be applied directly to the skin to monitor the heart's electrical activity, offering a potential alternative to spotting problems such as heart attacks. Unlike conventional clinical sensors, the ink dries into a functioning electrode while remaining customisable with food dye, meaning it can be shaped into colourful designs, such as a shark, rather than resembling a typical hospital-style patch. This blend of medical function and body-art aesthetics could make continuous heart monitoring less clinical and more discreet for users.

The washable sensor was created by a team at Penn State, which has filed a provisional patent for the technology. Their findings were published earlier this month in the Proceedings of the National Academy of Sciences, and the tattoo has also been demonstrated tracking ECG readings and controlling a robotic hand.