Breath, blood and urine–law enforcement officials use a variety of tests to determine if they should charge a driver with DUI. Here’s a look at the science behind the various types of tests and what you should know about the pros and cons of each in the event that police arrest you for driving under the influence.
School Testing
Measuring your breath
Would the number of DUIs in Los Angeles decrease if drivers and/or police officers had an easier, more reliable way to measure blood alcohol content? 
Researchers at the University of San Diego have developed a wearable, flexible sensor that can accurately measure a person’s BAC from sweat. The device, a temporary tattoo, actually induces sweat and then detects the alcohol levels electrochemically. The device communicates the information to a mobile device—laptop, tablet or phone—via Bluetooth.
Nano engineering professor Joseph Wang and electrical engineering professor Patrick Mercier led the team that developed the sensor. “This technology provides an accurate, convenient and quick way to monitor alcohol consumption to help prevent people from driving while intoxicated,” said Wang. He envisions interfacing the device with an ignition interlock device, or people using it to monitor their own alcohol levels so they could refrain from driving if they were legally under the influence.
Los Angeles DUI Attorney Blog