As colour ink-jet printers get better, it is becoming ever more expensive to foil banknote forgers. The latest wheeze, from paper manufacturer Landqart in Switzerland (world patent filing WO 2004/104277), is to embed fine, photoluminescent polymer fibres in banknote paper. These 3-millimetre lengths of cellulose are coated with a UV-sensitive dye such as stilbene.
Landqart found that if the cross section of the fibres is a squashed oval or a flattened rectangle, they rise to the surface of the cotton-based banknote paper pulp as it dries. That side of the paper then shows bright specks of light under a UV lamp.
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Video pirates can extract pay-TV codes from a smartcard by using an array of electrical probes to assess the state of the 0s and 1s stored by the transistors in the embedded chip. Honeywell of New Jersey say this can be prevented by covering the chip surface with a fine metal mesh (WO 2004/102662). When the pirate鈥檚 probes touch the mesh, they activate piezoelectric crystals attached to it, producing a pulse of electricity that corrupts all the data stored on the chip.
Body armour made of fabric reinforced with Kevlar is usually too bulky and stiff to wear over arms and legs. So the University of Delaware, working with the US army, has developed a way to make a more flexible fabric (WO 2004/103231). Their new armoured material is made from two dozen thin layers of nylon impregnated with fine particles of silica or a polymer such as polystyrene.
Most of the time the particles act as a lubricant that helps the layers slide freely against each other as the material flexes. But a sudden impact from a knife or bullet squeezes the particles of neighbouring layers together. With the material no longer able to flex, it will stop a knife point or a bullet getting through.
