Qinetiq, the Farnborough defence research centre, may soon revolutionise our grocery shopping habits.

Tills, conveyor belts, plastic bags and queues at the check-out may soon be a thing of the past, with shoppers simply pushing their trolleys past scanners which instantly total and print out their bill.

The breakthrough has come with the development of a magnetic ink containing cobalt.

Under the new system, groceries will be placed in detachable trolley boxes, ready to lift into your car boot. Each item will have magnetic stripes converted into a number by a metal coil. The scanning device is so sensitive that it can cope with the jumble of numbers passing through the sensor at the same time.

Supermarkets have been trying for years to find a way of scanning the entire contents of a trolley and trials are underway, but the cost has to be low enough to make a new system viable.

Said Chris Coomber, director of Qinetiq's Metal Printing at Farnborough: "We think low costs are now achievable. The clever part of the technology is in the magnetic ink."

The downside is that many jobs may be lost as tills become redundant, but one benefit is that plastic bags will no longer be needed.