Aug. 14, 2002 That bar code on your cereal box holds information read by a laser scanner. It's not much information, but it's enough to let the supermarket take your money, keep track of inventory, follow trends in customer preference, and restock its shelves. Scanners and bar codes speed up checkout, but they've got a few limitations. The scanning laser needs a direct line of sight to the bar code, and the bar code itself needs to be reasonably clean and undamaged – one reason your cashier might have to swipe that bag of spuds four or five times before the scanner reads it.
Now there's something better, and it comes out of an Office of Naval Research program that goes back four decades. Very small electric crystal chips can now be embedded into products to provide up to 96 bits of information when they're read by an electromagnetic scanner. (That's roughly 6 times as much as bar codes hold. It also meets the new industry standard developed by the MIT-led Auto-ID Center.) These new radio-frequency scanners, unlike the optical ones in most supermarkets today, can read the chip whether they have direct line-of-sight to it or not. And dirt? Ordinary dirt matters not at all.
The chips themselves are so small (less than an inch long with the antenna attached, and only about as thick as a pencil lead) and so simple that they don't need a power source--it all comes from the scanner. The new chips store enough information to uniquely tag just about every individual manufactured item. In effect, the scanner reads not only the category and model number, but a serial number for the particular item that bears the tag. The tags can be used for all kinds of marking, supply, tracking, inventory management, and logistical tasks. Imagine checking out by just pushing your cart through the supermarket's door--that's one of the new possibilities some major retailers are looking at.
From 1962 to 1976, the Office of Naval Research (ONR) sponsored development of "surface acoustic wave (SAW) technology" for filters in electromagnetic systems, electronic warfare surveillance devices, color TV receivers, and other devices of use to the Navy and Marine Corps. The original work was performed at Texas Instruments by Clinton Hartman and Lew Clairborne, who have since spun the technology off into their Texas-based company, RF SAW, Inc.
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