New sunscreen stickers alert you when you need to reapply
This isn’t the first product of its kind. A company called LogicInk sells a UV-sensing temporary tattoo that works in a similar way.
NANO-TECHNOLOGY — Tattoo electronics that attach directly to the skin and monitor biochemical signals, like hydration levels, have become a fast-growing field of research in part because the technology has come down dramatically in cost. Because sensors are getting smaller in size, tattoo-based electronics have the potential to offer real-time monitoring of health signals as a person goes about their day, but without creating discomfort. Stickers with embedded sensors can easily be 3D printed to different shapes and sizes.