If third-year engineering graduate student Scott McCain gets his way, the fight against drunk driving may soon be waged with a new, non-invasive blood alcohol sensor that could make standard blood or breath sample tests obsolete. The St. Louis native’s interdisciplinary research - a combination of engineering, physics and computer science - aims to build a small and inexpensive optical device capable of using harmless light to pass through skin and directly determine blood alcohol concentration.

“The device uses light at wavelengths at which skin essentially becomes transparent,” McCain said. “We shine a laser through tissue where it interacts with blood. By analyzing the scattered light that comes back out, we can determine much about the blood’s chemical content.”
…
Similar devices hold promise for determining other constituents of blood. For example, they could measure cholesterol or blood sugar in a matter of minutes, McCain said. Ultimately, the goal is to have a sensor that could report a medical reading in less than 10 seconds.
…
“We don’t yet know if our blood alcohol sensor will really work,” said McCain. “It wouldn’t be research if we knew what it was all about.”