Sometimes, after a few drinks, people get a tattoo. Now there’s a tattoo that can tell if you’ve had a few drinks. Best of all, it’s temporary.

Researchers at the Center for Wearable Sensors at the University of California, San Diego, have come up with a removable electronic tattoo that can sense your blood-alcohol level from the sweat on your skin and then send this information via Bluetooth to a smartphone or car computer.

The...