TEMPORARY TATTOOS and BAC

WHEN OUT at a bar and enjoying drinks it’s never a bad idea to know what your BAC is. Recent studies have demonstrated that sweat can be a highly reliable real-time indicator of blood alcohol content. Researchers Joseph Wang, Patrick Mercier and colleagues from the University of California, San Diego have created a new piece of technology to monitor your alcohol intake and report the results back to your smartphone. The device is a wearable electronic board, which “clings to the skin like a temporary tattoo” to help revelers keep an eye on their intake on a night out by reading the level of alcohol in the sweat. With temporary-tattoo paper, the researchers developed a patch that tests blood alcohol content non-invasively in three rapid steps. First it induces sweat by delivering a small amount of the drug pilocarpine across the skin. An enzymatic reaction then leads to the electrochemical detection of the alcohol content. Finally, a flexible electronic circuit board transmits the data via a Bluetooth connection to a mobile device or laptop. The steps take less than 8 minutes from start to finish. In addition to connecting to vehicles’ ignition interlock systems, the sensor could be a simple tool for bartenders, friends or law enforcement to use, the researchers said. “Right now, the tattoo is designed for one-time use,” said Mercier.