An elementary school student in Shanghai will no longer have to worry about his father drinking and driving after he invented a gadget which automatically cuts off the power once it "smells" alcohols in the car.

The gadget Zhou invented functions as an alcohol-monitoring machine, which will be fastened to the metre board in front of the driver's seat. The device continuously samples the air exhaled by the driver. Once the percentage of alcohol in the air reaches a risky level, the gadget, which connects to the electric circuit of the car, automatically and immediately cuts the power. Zhou won a second-place prize at a national children's invention competition for the device a few days ago.

A local automotive expert said Zhou's invention was practical and should be introduced to the market soon.