The Kérastase Hair Coach, dubbed a world first by the two companies, incorporates a number of sensors that can detect the quality of hair while it is being brushed.
A microphone picks up the sound of the hair running through the bristles to detect frizziness, dryness, split ends and breakage. Three-axis load cells – which create an electrical signal directly proportional to a measured force – also analyse the pressure put on the hair and the scalp when brushing.
An accelerometer and a gyroscope help to further analyse brushing patterns while counting brush strokes, and also send vibrations if brushing is too vigorous.
The sensors can also detect whether the brush is being used on dry or wet hair in order to provide an accurate hair measurement.
"Technology is transforming consumers' daily beauty routines, and smart devices have huge potential to impact how we care for our hair and skin," said Guive Balooch, global vice president of L'Oréal's Research and Innovation Technology Incubator, which brands its hair products under the Kérastase label.
"By using connected technologies to upgrade the hairbrush — something the average consumer uses every day — Withings and Kérastase have reinvented what a person's relationship with their hair can look like and are showing how connected devices can revolutionise the beauty industry."
Each of the sensors automatically feeds data back to the user's dedicated mobile app via Wi-Fi or Bluetooth.
The app then factors in current weather conditions like humidity and temperature, before providing a hair quality score, personalised tips and product recommendations.
The brush will be on show at this year's Consumer Electronics Show (CES) in Las Vegas, which takes place from 5 to 8 January 2017.
Designers and technology companies are increasingly working to create smart versions of regular home, health and beauty products.
Examples range from Philippe Starck's smart radiator valves, which allow homeowners to remotely control the temperature of each room using their voice, to New Deal Design's Fever Scout thermometer that allows parents to monitor a child's temperature remotely.