Researchers at the Center for Optics, Photonics and Lasers of the University of Laval, Canada, have created a breathalyzer that can be built into a smartphone.

The problem is that modern technologies for determining the level of alcohol in blood are not suitable for integration into telephones. Indeed, they are cumbersome, expensive, difficult to mass-produce, and fragile due to the need to replace chemical sensors.

Rather than trying to integrate existing breathalyzer technology into a phone, Canadian researchers wondered if existing components in phones could be used to measure blood alcohol content. This question led them to an interesting invention: an optical breathalyzer built into the phone screen. The principle of operation is based on the evaporation of breathing mist on the screen. When a window becomes fogged, thousands of micro-droplets form on its surface. When the breath contains alcohol, these microdroplets evaporate faster because the alcohol evaporates faster than the water in the breath of a sober person.

Researchers have created a prototype with a dedicated application. There is only one component to add to the phone: a photodiode. It’s affordable and is often built into modern phones. Scientists have tested to understand the parameters and conditions that can affect measurements.

It turned out that while the technology works well in a controlled environment, the environmental conditions in a real environment strongly affect measurements. In the future, scientists plan to correct this defect. Also, after the accumulation of a large database, scientists plan to use AI to obtain accuracy, “which will convince major phone manufacturers to integrate breathalyzers into screens,” the scientists conclude.