Scientists in Japan are busy perfecting a carpet that they hope one day will tell retailers exactly what type of people have been coming into their shops.

A research team at the National Institute of Advanced Industrial Science and Technology has developed a carpet that can categorise people by age and gender by concealing tiny electronic sensors between the carpet and the floor.

As subjects walk over the surface of the carpet that contains a thin layer of silicone rubber with built-in electrodes, a change in electrical resistance and current flow is shown depending on the forces applied to it as a person walks.

The researchers say retailers will be able to glean shopping patterns and customer demographics such as weight, age and sex by having the carpet measure shoe size, gait, walking speed, weight and centre of gravity.

By studying a group of 300 people, the team determined certain relationships, such as the fact that for a given foot size, younger people walk faster and with a longer stride.

The prototype carpet can distinguish between people in their 20s and 60s with nearly 100% accuracy. Precision is around 50-60% for people in their 30s, 40s and 50s.

And gender can be determined with 70-80% accuracy based on the fact that males and females have different centres of gravity.

By Michael Fitzpatrick.