A new kind of smart key could help drivers make a very important decision not to drive when they've had too much to drink. Honda and Hitachi have teamed up to develop a prototype of a portable breathalyzer that's integrated into a smart car key, and can keep your car from starting its engine if you've had one too many.

The handheld device is roughly similar in size and shape to a small smartphone and can detect alcohol in human breath within three seconds of someone exhaling on to it. The companies also claim that it can distinguish real human breath from other gases.

The key can also be used with a system that the team developed, which shows the alcohol level measured by the detector on a vehicle's display panel and works as an ignition interlock to stop a vehicle engine from starting if it is detected that a driver has had too much to drink.

We've seen similar devices to ward off drunk biking and help you call a cab when you've had too much, but few handheld devices can also integrate with the car to shut things down.

Common ignition interlock technology in use today requires a driver to blow into an alcohol detector from the driver's seat of a vehicle. Hitachi and Honda argue that their smart key holds an advantage in that it can render a verdict on a driver's ability to operate a vehicle safely without having to first step in to a car, thereby reducing the temptation to drive anyway.

The sensor technology inside the smart key was developed by Hitachi and is made up of an oxide insulator between a pair of electrodes. Water vapor in human breath allows electric current to flow between the electrodes, enabling the system to recognize the exhaled gas as breath. The sensor area is only a 5 mm square and battery-powered, allowing it to be portable enough to put in a pocketable key.

The device can detect as little as 0.015 mg/L of concentrated ethanol – 0.15 mg/L is the legal limit that can constitute a charge of drunk driving in Japan.

While the technology is just in prototype form now, the companies say they will continue to test it in hopes of commercializing it in the future.

Source: Hitachi

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