TECHNOLOGY FOR CHANGE

Check It Out: Nano RFID to Speed Purchases

Stan Gibson | Date: 04-01-10 | Comments

Supermarket lines may disappear thanks to nano RFID.

You fill your cart with groceries and then head straight for your car. No need to wait in line at check-out because you pass a scanner that reads all the items in your cart at once, totals up the cost and charges your account. At the same time, the system adjusts the store's inventory.

That utopian vision is closer to reality than you might think. Researchers at Rice University, in collaboration with a team at Sunchon National University in Korea, are hard at work on inexpensive, printable RFID transmitter technology that can be invisibly embedded in packaging. The printable RFID tags power up when hit by radio waves at the right frequency and return the information they contain.

While supermarket bar-code scanning and RFID technology are not new, two barriers to RFID adoption in place of bar codes have been size and cost. The Sunchon and Rice researchers have been attacking those two obstacles.

�Wal-Mart said five years ago if you get the price of an RFID tag to a penny, we�ll implement them. Our cost is now three cents each, and we�re working on lowering it to one cent each,� says Jim Tour, professor of chemistry at Rice in Houston. The Rice and Sunchon researchers have decreased the size of their printed RFID tags to 5 by 9 cm. Typical bar codes are 3 by 3 cm, Tour relates.

Tour�s lab at Rice came up with a carbon-nanotube-infused ink, which is used to make thin-film transistors, a key element in RFID tags that can be printed on paper or plastic. To print the tags, Gyou-jin Cho, professor of Printed Electronics Engineering at Sunchon, came up with a gravure printing process, rather than the more expensive ink-jet printing.

Cho, Tour and their teams have completed a three-step process to print one-bit tags, including the antenna, electrodes and dielectric layers, on plastic foil. Cho's lab is working on 16-bit tags that would hold a more practical amount of information and be printable on paper as well.

�Right now, the emitter has to be pretty close to the tags, but it's getting farther all the time,� states Tour. �The practical distance to have it ring up all the items in your shopping cart is a meter. But the ultimate would be to signal and get immediate response back from every item in your store�what's on the shelves, their dates, everything.�

�We are going to a society where RFID is a key player,� adds Cho, who expects the technology to mature in five years. The researchers published a paper on the technology, which can be accessed from the IEEE Xplore digital library.