Hitachi and Honda have developed a prototype of a portable alcohol detector that can be integrated into a smart key. The prototype is tamper-resistant and can distinguish human breath from alternative gases. It is capable of detecting the saturated water vapor from human breath and accurately measures blood alcohol levels within three seconds.
The two companies have also developed a system that can show on a vehicle’s display panel the alcohol level measured by the detector. The system could become an ignition interlock to stop a vehicle from starting when it detects that the driver is under the influence of alcohol.
The prototype also offers a number of advantages over other ignition interlocks. Currently, other systems require drivers to perform the test from the driver’s seat once inside a vehicle. This device enables drivers to measure their alcohol level from anywhere prior to entering their vehicle, thus reducing the temptation to drive. In addition, its ability to confirm that the applied gas is human exhaled breath and detect the level of alcohol present simultaneously is an enhancement over currently available devices.
The sensor that detects saturated water vapors from human breath consists of an oxide insulator sandwiched between electrodes. Breath is absorbed by the insulator and electric current flows between the electrodes.
In compliance with Japan’s regulations related to drink driving, the device has an improved ability to measure the ethanol concentration of exhaled breath. The ethanol concentration is measured by three types of semiconductor gas sensors that detect ethanol, hydrogen and metabolized acetaldehyde in breath after drinking.
This method improves accuracy threefold compared with devices that only use an ethanol sensor for measurement. The device is also capable of measuring as little as 0.015mg/L (an ethanol concentration) compared with 0.15mg/L of the alcohol, which constitutes being ‘under the influence of alcohol’ and drunk driving in Japan.
By applying the alcohol detector’s recorded measurement result into the engine ignition mechanism, the system prevents the vehicle’s engine from starting if it detects that the driver is over the preset limit. An alert indicator also shows the measurement results on the vehicle’s display panel if the detector equipped smart key is close to the driver seat.
Hitachi and Honda are aiming to commercialize the technology through collecting data from future validation tests.
March 30, 2016