Printed RFID Tags Still Several Years Away

"The biggest potential [for printed RFID]," Das said, "is in open-loop supply chains. Standards and performance issues will be ironed out by 10 years from now." At present, there are no standards for printed RFID tags, and no organization is working to create them.

Speaking at the conference, Andreas Fuessler, a senior project manager for GS1 Germany, urged attendees to establish standards. He noted, however, that EPCglobal, a division of GS1, is not presently working toward such a goal, due to a lack of interest from its members.

Raghu Das

In his presentation, Das cited printed thin-film transistor circuits (TFTCs) as one of the most promising technologies for low-cost RFID tags. TFTCs would support RFID tags operating at frequencies of up to 13.56 MHz, he said. Rugged, thin and robust, they could cost less than 3 cents per tag and would allow for a rapid design and production turnaround.

"TFTCs can go higher than 13.56 MHz," Das explained. "Today, that is the highest frequency demonstrated, but we know some may be able to achieve UHF and higher. [The] cost is our very rough estimate, as you need high capital installation. Taking into account yield issues, etc., 3 cents is what we think it may be, but it could be higher or lower initially. We do see it getting much cheaper than that, as it becomes more robust."

"Ultimately," Das stated, "we see printed as the biggest in volume of all RFID, but it will take a while. I don't see this ramping up until 2011 or 2012." He added that he does not believe printed RFID tags will ultimately replace those made from silicon. "Both will coexist for a long time," Das predicted. "Silicon, being developed for many decades, is very robust and has a great deal of sophistication. Printed TFTCs are just starting on that curve, and will initially be suited only for very simple, low-memory devices with short range. They will improve, though, and with time, will eat increasingly into silicon RFID. But this is at least 10 years away, and could be much longer."

Asked to list the major challenges of getting to a fully printed RFID tag, Das said there are dozens—among them the mobility of a printed transistor's electrons, print resolution, yield and encapsulation—all of which affect the frequency of operation, lifetime, memory capacity, read range, read speed, tag size and other parameters. He noted that hundreds of organic electronics companies are currently working to address such issues. "It will take another three to four years," he said, "to get a commercial product." Once the printed RFID tag has arrived, however, an additional challenge will surface—namely, how to print a tag directly onto product packaging.

Bruce Lyne, president of Sweden's Institute for Surface Chemistry (YKI) spoke at the conference as well, focusing on how to improve paper and packaging surfaces for printing RFID. His conclusion: Before tags can be printed on packaging, much research needs to be done. In addition, Lyne advised that developers looking to build printed RFID tags determine which tag design offers the most promise before worrying about standards (see VTT Is Developing Printed Sensors).