Marlin Mickle displays his invention—a microchip with a built-in antenna—on his right index finger and a penny between the thumb and index finger of his left hand.

Pitt Engineer First to Put an Antenna On a Microchip

A recent commercial by a computer industry giant depicts a seedy-looking man walking through a store, furtively putting items in the pockets of his trench coat. As he passes through an exit, a security guard stops him.

“Excuse me, sir,” the guard says, “You forgot your receipt.”

The commercial suggests that the technology to make this effortless checkout is nearly five years away, but according to Marlin Mickle, Nickolas A. DeCecco Professor in Pitt’s School of Engineering and director of the University’s Center for Motion Control Research, the technology is here today, and it works. A project, funded by the Defense Advanced Research Agency, is led by principal investigators Mickle and Richard E. Billo, professor and head of the department of industrial and manufacturing engineering at Oregon State University, who demonstrated it in the summer of 2000 using commercially available radio frequency identification (RFID) tags.

Mickle and his research team had a breakthrough in RFID technology late last year, when the team became the first to successfully incorporate an antenna directly onto a Complementary Metallic Oxide Semiconductor (CMOS) chip in order to have that chip relay information to a base receiver.

The antenna on a chip—called PENI Tag, for Product Emitting Numbering Identification Tag—could replace present RFID tags, the current industry technology, before the end of the year. The technology also could open the door for myriad other uses, from anticounterfeit technology in currency to biofeedback for people with epilepsy or heart disease. The most immediate application of the antenna on a chip, however, is to help RFID technology replace bar codes on commercial products.

“RFID tags are destined to replace bar codes in many commercial applications, eliminating the problem of finding the bar code and correctly orienting it toward the scanner,” said Mickle. “The primary drawback has been the relatively high cost of the RFID tag compared to bar codes.”

Currently, RFID tags are manufactured with a silicon chip containing the needed information, price, model number, or serial number, for instance. The chip is attached to an antenna that transmits the information to a receiver, and both the chip and antenna are mounted on a plastic or paper tag.

The expense of assembling the chip and the antenna and affixing them to the tag is primarily responsible for the high cost, which, at 30 to 50 cents apiece, dissuades many manufacturers from using them in place of bar codes.

“The people in the industry always said that the technology wouldn’t take off until the cost approached a penny a tag,” said Mickle. “Well, it appears our chip can be made for pennies in current projected volumes, hence the name, PENI Tag.”

The PENI Tag, dwarfed by its eponym, a U.S. penny.

The small size of the chip, 2.2 millimeters square, will help it gain acceptance in the retail world as well, since it will be less conspicuous on or embedded in products and less likely to be removed or tampered with by consumers. Mickle hopes to reduce the size of the product to 1000 microns square—less than half its current size.

The types of information that can be stored on the chip are limited only by the user’s imagination, because thousands of bytes of information can be stored on a single chip. Mickle and Ming-En Wang assistant professor of industrial engineering in Pitt’s School of Engineering, are exploring other uses in what they hope will be a Pitt-dominated research effort.

Mickle and his colleagues are best known for their research in remote sensing and energy harvesting for small devices. The chip harvests radio frequency energy, which it converts to direct current, to power the electronics and to transmit the data. Mickle said that the distance the signal can carry—perhaps as far as 100 meters—could vary depending on circumstances.

Mickle’s work has been primarily supported by the Pittsburgh Digital Greenhouse, a joint venture of Pitt and Car-negie Mellon University created by former Pennsylvania Governor Tom Ridge to foster the “system-on-a-chip” industry in the Pittsburgh region. • JF