Antennaless RFID tags and ‘smart’ paper

New research will enable on-metal RFID tags to use the structure of the tagged object as the antenna.

Research teams at North Dakota State University (NDSU), Fargo, have developed a method to embed radio-frequency identification (RFID) tags in paper, which could help combat document counterfeiting, and also have developed antennaless RFID tags for use on metal. The researchers presented their technology advances recently at the RFID Journal LIVE! and IEEE International Conference on RFID meetings in Orlando, Florida.

As part of the IEEE International Conference on RFID, Cherish Bauer-Reich discussed research at NDSU’s Center for Nanoscale Science and Engineering to develop on-metal RFID tags that use the structure of the tagged object as the antenna. This research has been featured in publications such as RFID Journal, R&D Magazine and Gizmag. Her talk was part of a workshop on enhancing near-metal performance of RFID.

Layne Berge, a graduate student in Electrical and Computer Engineering at NDSU, presented a paper titled ‘A UHF RFID Antenna for a Wireless Sensor Platform with a Near-Isotropic Radiation Pattern’ as part of the IEEE conference. The paper was co-written with Dr Michael Reich, a senior research engineer at NDSU. The research focuses on developing spherical sensor platforms that can communicate using RFID protocols, regardless of orientation. This is useful for sensors that cannot be deployed with a guaranteed orientation, such as those dropped from aircraft.

Dr Val Marinov’s team has developed a method to embed ultrathin, ultrasmall RFID chips on paper or other flexible substrates, which could lead to ways to reduce counterfeiting of a wide variety of items such as pharmaceuticals, currency, legal papers, bearer bonds and other security documents. The patent-pending process, known as Laser Enabled Advanced Packaging (LEAP), uses a laser beam’s energy to precisely transfer and assemble chips with dimensions well below those possible using conventional methods.

The embedding method involves chips thinner than most commercial RFID chips on the market today.

“We use our LEAP technology to embed ultrathin, ultrasmall semiconductor chips, including 350 µm/side, 20 µm thick semiconductor dice, in paper substrates with a thickness of <120 µm,” said Dr Marinov, associate professor of industrial and manufacturing engineering at NDSU.

RFID-enabled paper could be used to reduce counterfeiting and to improve the tracking of paper documents of all kinds, according to Dr Marinov. In addition, this method could enable the production of paper-based RFID tags at a cost lower than that of today’s conventional RFID tags and at packaging rates multiple times higher than those attainable with the conventional pick-and-place technology.