Labeling with nanobarcodes

DIAMONDS and valuable worksof art could be protected against theft using a microscopic barcode that storesencrypted information about the provenance of the items, making ownership easyto prove if they are stolen.The barcode, which takesthe form of a cube 30 micrometres across, is being developed by a team at theNational Physical Laboratory (NPL) at Teddington, near London. The cube is made of silicon coatedwith a 100-nanometre-thick layer of polymethyl methacrylate, a transparentplastic. It can be attached to hard surfaces using adhesive, or woven into thecanvas of paintings.To create the barcode anelectron-beam lithograph drills 90,000 small squares into the plastic coat ofeach face at five different depths. The position and depth of each square isunique, so data can be encrypted using a key-based code and stored digitally. Thecube is scanned line by line using an electron force microscope, which candetect differences in the depth of the squares. This scanning process takesaround a minute, says Alexandre Cuenat, one of the team of researchers thatdeveloped the cube.

Source: newscientist.comAdded: 2 October 2006