Silver News
Silver Antennas Keep ‘Smart Tags’ In Touch
By Samuel Etris, Senior Technical Consultant to The Silver Institute
From grocery items to pre-paid toll gizmos, Radio
Frequency Identification or RFID devices are coming on in a big way. Not only are these tiny ‘smart tags’ fast replacing bar codes at the checkout counter, but they’re being used to prevent shoplifting, trigger warehouse inventory counts and will soon make an appearance imbedded in credit cards and passports.
RFID devices are usually passive – there’s no battery power – and are energized by radio signals from a transmitter generally located a few feet away. The tag responds to the
signal by sending its own information identifying the product. At the heart of the device is a computer-type chip, but it relies on a flat, silver antenna to send and receive data.
Smart tag antennas are manufactured by the printedsilver process in contrast to the alternative, the acid etching
process which uses corrosive chemicals. The silver printing process is an additive process so only the required material is applied versus the wasteful and subtractive etching process.
|
|
Although the amount of silver used in each smart tag is miniscule, tens of millions of throwaway tags are expected to be produced in coming years and the applications appear
virtually endless. Silver makes a perfect antenna because it is highly conductive and malleable. The silver printing process is well established, and the price of tags is expected to drop to just a few pennies each in the next several years.
Wal-Mart, the world's largest retailer and the U.S. Department of Defense are pushing vendors to include tags on shipping pallets because RFID devices can boost supply chain efficiency. In warehouses, the tags are used to track pallets and provide instantaneous inventory. Tags also are ideal for tracking items in a clean room production line where manual handling would be unacceptable. Tags track parts movements in regular assembly lines and trucks as they progress through terminals
|
and railroad yards. The Port of Los Angeles uses RFID tags on trucks to monitor access to the gated entrances and exits.
Smart tags are manufactured by Texas Instruments, Motorola, Philips, Matrics, and many others.
Smart tags represent a new application for silver printing but the technology has been used in other electronics devices for years. It provides circuits for plasma television displays, membrane touch switches used in all keyboards from computers to machine controls, and in microcircuits for motor controls in automobiles, trucks, railway cars and elevators.
Silver News - Third Quarter 2005
|
