Two Chinese students have invented a device that might mean ‘giving the finger’ before you even start your car. Zhao Wencai and Li Zhoumu, from China’s University of Geoscience, have built a finger print reader that doubles as a blood alcohol detector. It’s purely a prototype, but it works by detecting sweat and other chemicals on the skin. If you’re dripping with alcohol you won’t be able to start your vehicle. Additionally, the finger print reader will double as a security device and will only let registered finger prints start the vehicle.