Researchers at North Carolina State University have made what is believed to be the smallest state-of-the-art RFID chip that should lower the cost of RFID tags. In addition, the design of the chip allows RFID tags to be embedded in high quality chips such as computer chips, increasing the security of the supply chain for high-end technologies.
“As far as we can tell, it is the smallest Gen2-compatible RFID chip in the world,” says Paul Franzon, corresponding author of a paper on the work and Cirrus Logic Distinguished Professor of Electrical Engineering and Information Technology at NC State.
Gen2 RFID chips are state-of-the-art and already widely used. One of the things that make these new RFID chips stand out is their size. They measure 125 micrometers (μm) by 245 μm. Manufacturers were able to make smaller RFID chips using earlier technologies, but Franzon and his staff were unable to identify smaller RFID chips that are compatible with the current Gen2 technology.
“The size of an RFID tag is largely determined by the size of its antenna – not by the RFID chip,” says Franzon. “But the chip is the expensive part.”
The smaller the chip, the more chips you can get from a single silicon wafer. And the more chips you can get from the silicon wafer, the cheaper they are.
“In practice, this means that we can produce RFID tags for less than a cent each if we produce them in large quantities,” says Franzon.
This makes it easier for a manufacturer, distributor, or retailer to use RFID tags to track lower-cost items. For example, the tags could be used to keep track of all products in a grocery store without staff having to scan items one at a time.
“Another advantage is that the design of the circuits used here is compatible with a large number of semiconductor technologies, such as those used in conventional computer chips,” says Kirti Bhanushali, who worked on the project as a doctoral student. NC State student and lead author of the work. “In this way, RFID tags can be integrated into computer chips so that users can track individual chips throughout their lifecycle. This could help reduce counterfeiting and verify that a component is what it says it is. “
“We have shown what is possible and we know that these chips can be made with existing manufacturing technologies,” says Franzon. “We are now interested in working with industrial partners to study the commercialization of the chip in two ways: creating low-cost, large-scale RFID for use in sectors such as grocery stores; and embedding RFID tags in computer chips to secure high quality supply chains. “
The paper “A 125 μm × 245 μm mainly digital UHF EPC Gen2-compatible RFID tag in the 55 nm CMOS process” was presented on April 29 at the IEEE International Conference on RFID. The paper was co-authored by Wenxu Zhao, who was a PhD student on the project. Student at NC State; and Shepherd Pitts, who was a research fellow at NC State on the project.