Using Science to Stop Shoplifting

Every sixty seconds somewhere in Germany a shoplifter strikes. Each year, theft costs retailers around two and a half billion euro. Petty thieves steal a wide range of objects from store shelves, but they’re particularly found of razor blades, halogen light bulbs, condoms and cosmetics -- small items they can slip into their pockets.

Department stores use a variety of weapons in their battle against shoplifting: security cameras, in-house detectives, and the now ubiquitous – and costly – security tags, small electronic beepers attached to the store item.

Electromagnetic systems are supposed to help deter potential thieves. But the moment the new technology started popping up everywhere, resourceful shoplifters quickly found new ways of tricking the technology. Many simply tuck the items into their bags and inconspicuously walk out the front door. And because of faulty tags, the system doesn’t detect that the shoplifter has left the store.

New metal wonders

Now scientists working in a vacuum smelter laboratory in Hanau, Germany, have developed a new security system for retailers which makes use of characteristics intrinsic to amorphous metals. Whereas atoms in normal metals are ordered into regular crystal lattices, atoms in amorphous alloys are distributed irregularly as though the metal were a suspended liquid.

Creating this kind of alloy is an elaborate process. Iron, cobalt and nickel first have to be purified, melted and combined. The most important part of the procedure is when the molten metals are sprayed onto a rapidly rotating copper drum. In less than a thousandth of a second, the material cools down from 1300 degrees centigrade to room temperature.

The end result is a strip of metal with unique characteristics. It is as thin as human hair and the strips can be magnetically polarized, which means they can broadcast signals. And it’s this capability that is the key to the development of a new, miniaturized security tag.

Dr. Giselher Herzer, a physicist in Hanau explains that the tags are based on two metal strips that function like a magnet. "One of the strips is the actual sensor," he says. "It’s the heart of the tag, the part that triggers the alarm. The second strip is a small, flat permanent magnet. That’s the on-off switch. Depending on whether it’s magnetized or demagnetized – the tag is either activated or de-activated."

The Hanau laboratory is already producing several million of the smart new security tags every day.

More secure shopping

Changes in stores’ security systems will be invisible. Customers will continue to see the detection gates at store exits, and the same chunky security tags will dangle from all sorts of items. When a shoplifter tries to smuggle merchandise out of the store, the hidden strips will set off an alarm – not the blaring beeping everyone knows so well, but rather a faint signal.

An antenna inside the store listens carefully for the strip’s magnetic echo. Only a cashier can deactivate the strips hidden in the merchandise, demagnetizing them by passing the tags over a magnetically-charged surface. And the tiny tags only stop broadcasting their faint signal when they have been deactivated, a fact that provides stores with a higher level of security.

Dr. Herzer says that the new tags are more dependable than their older counterparts. For retailers they also have the added advantage of a small size, which makes them easier to hide. They can be placed inside a product’s packaging or even taped under clothing labels.

The smart strips have already become a hit among retailers. They’re cheap, dependable and make it more difficult to outsmart store security systems. For shoplifters in Germany, times are getting tougher.