If you’re a responsible adult, you don’t drink and drive. But sometimes it’s hard to tell whether you’ve had too much to be able to safely do so, and breathalyzers aren’t always useful. To that end, scientists at UC San Diego have been developing a temporary tattoo than can measure blood alcohol content, the Press Herald reports. 

 

Sweat has shown to provide a more accurate measurement of blood alcohol content than breath. For instance, humidity can skew a breathalyzer. The researchers at San Diego have created a system of micro-sensors that attach to the skin with a temporary tattoo. The tattoo paper delivers a miniscule amount of pilocarpine, which stimulates sweating, then electronically measures blood alcohol. The device can then send the information to a bluetooth device, such as a smart phone. The process takes eight minutes.

 

The tattoos could serve a variety of functions, from electronically shutting down vehicles of intoxicated people, to being used by bartenders or friends to judge alcohol levels. The team behind them have proposed single use tattoos for a night out. The technology could provide a valuable tool for taking responsibility of drinking habits and safety at low expense.