Hitachi-Honda technology combats drunk driving

By Christopher A. Sawyer
The Virtual Driver

(May 30, 2016) If Hitachi and Honda have their way, driving drunk will become much more difficult in the near future. The companies have developed a portable breathalyzer that can be integrated into a smart key with a footprint about the size of a small smartphone. In addition, the unit is tamper-resistant, can distinguish human breath from other vapors, and returns an accurate reading of alcohol levels within three seconds.

There’s even an in-dash unit that displays the alcohol level measured. It can be integrated into an interlock that prevents an impaired driver from starting the car of the device detects they are legally under the influence.

Currently, interlock devices require that the driver perform a breath test from the driver’s seat. The Hitachi-Honda unit lets drivers measure their impairment level prior to entering the vehicle, and it is hoped this will reduce the temptation to drive.

To make this unit possible, Hitachi developed a miniaturized oxide sensor sandwiched between electrodes. It can detect saturated water vapors with a high degree of accuracy, despite a sensor area of just 5 mm (0.2 in.) square. The ethanol concentration in the breath being measured flows over three semiconductor gas sensors that measure ethanol, hydrogen and metabolized acetaldehyde present in the breath after drinking. Hitachi claims it is capable of measuring as little as 0.015 mg/L. In comparison, 0.15 mg/L of alcohol is enough for a drunk driving charge to be levied in Japan.

The electronics have been designed for use in current smart key designs, and integration into a vehicle’s ignition system. An alert indicator will show the results from the test on an in-vehicle display panel if the smart key is close to the driver’s seat. If the result is above a preset limit, the unit will prevent the car from starting.

Hitachi and Honda, who are looking to commercialize the technology, presented it at the SAE 2016 World Congress in Detroit last month.

The Virtual Driver