Although the idea of low-cost, printed
RFID tags fits neatly into the vision of a world of ubiquitous computing, in which everyday objects interact with one another and people, Seppä doesn't believe such technology will ever be as widespread as silicon-based tags—nor, he added, does it need to be. "The price of silicon tags is low enough for many applications," he said.
Rather, Seppä said, he imagines hybrid tags might emerge, consisting of silicon RFID chips integrated with printed antennas and printed sensors. According to Seppä, sensors such as one that records the highest temperatures to which a tag was exposed can currently be printed, and printed antennas are already common. For now, however, printed sensors are not a focus of the printed electronics market, since no such market yet exists.
VTT is developing a printed
sensor, Seppä said, adding, "The question is, is there a market? We cannot find a market for printed RFID sensors before we have widespread RFID infrastructure." He pointed out that in this area of printed RFID, developers also lack a standard for the interface between sensors and RFID tags.
Bruce Lyne, president of Sweden's
Institute for Surface Chemistry (YKI), also attended the pRFID conference. He agreed with Seppä that developers of printed RFID tags should not build an equivalent printed tag based on the model of an
EPC Class 1
Gen 2 tag. Instead, Lyne stated, they should consider the problem from the other direction—that is, they should determine which design for printed tags offers the most promise, then build that tag, worrying about standards later.
Asked how close the market presently is to offering a printed
RFID tag, Seppä said, "We are rather far away. The question is whether we will create new standards or work toward existing standards." If researchers in the field create new standards for a printed tag, he noted, fully printed tags will not arrive on the market relatively soon. "If we try to keep existing standards as they are they, we are far away."
At the conference, German company
PolyIC reported that it had demonstrated two organic RFID tags—one with 32 bits of
memory, the other with 64 bits—in a clean room. Separately, Seppä said VTT researchers have printed electric coding with
conductive ink that can be
read with a sweeping technique, or a contactless read in which a specially created
interrogator is placed close to the tag and moved along its entire surface. "For me," Seppä said, "this is already RFID."