A new system developed by Yarg Biometrics and funded by Strathclyde University can identify a child within seconds by scanning a finger or thumb. Piloted for two weeks at St Catherine’s primary in Balornock, Glasgow, last term, it will now be given a more robust trial in three schools across the city and Renfrewshire in August.

“It is a cashless system that gets rid of the need for money or smartcards, which kids can lose,” Alan Cunningham, Yarg’s managing director, said. “It is much harder to lose a finger.”

The technology uses thermal scanning to recognise different points on the finger, but it doesn’t hold enough information to take a full fingerprint.

“Biometrics is very much in the headlines now, especially with the United States government’s proposals for its passports,” Mr Cunningham said. “But we are looking at its commercial uses.”

The pilot at St Catherine’s gave the company an opportunity to observe how children accepted the technology.

Units were placed in two areas outside classrooms and the children were asked to swipe when they entered. The next test will see units stationed in dining halls.

“The technology does have advantages for schools,” David Parry, Glasgow’s head of operations for school meals, janitors and cleaning, said. “It worked well and I can see it having uses in other sections of the school, such as the library, class registration and access to secure areas.”

Finger swiping could also ease the stigma of free meals and deter theft or multiple use, where pupils share smartcards to gain more points in loyalty schemes or avoid paying card replacement fees.

The scheme was developed after the Scottish Executive announced that it wanted all of Scotland’s primary schools to move to a cashless system of selling food.