SK-Electronics Unveils Ant-Size RFID Tag

Japanese technology firm SK-Electronics has developed a passive ultrahigh-frequency (UHF) RFID tag that is less than 0.5 millimeters by 0.5 millimeters (0.02 inch by 0.02 inch) in size—small enough to fit on the back on an ant. For SK-Electronics, the fact that the tag can effectively transmit data (albeit with a maximum read range of about 2 millimeters, much shorter than the typical range of larger tags) means that the new Fine Tag, as it's called, could be applied to small products moving through the supply chain, for example, or requiring anti-counterfeit verification at a store. However, the company has chosen a uniquely challenging use case to put the tag to the test first: tracking the movements of individual ants. While the ant research project continues, SK-Electronics has begun marketing the Fine Tag for commercial use. According to Ichii Hirotaka, SK-Electronics' associate director, the company is now offering samples of the Fine Tag in small quantities, but expects to be able to fill large orders by the end of 2015.

SK-Electronics is primarily a photomask manufacturing company for LCD panels, which spun off from Kyoto printing company Shashin-Kagaku in 2001. Photomasks are plates used to restrict the transmission of light to a defined pattern in LCD panels. However, the firm recently began applying its engineering skills to developing a new RFID tag. For the past three years, it has been developing a product that would be smaller than other existing tags on the market. Such a tag could be used for tracking tiny items, such as surgical tools, pharmaceuticals or other medical supplies; for brand protection of small, high-value products; and for the management of small animals.

SK-Electronics' Fine Tag, shown here attached to a drosophila fly, measures 0.46 millimeters by 0.48 millimeters.

To test the new tag, the company sought a real-world challenge, which it found in ant research at the Kyoto Institute of Technology (KIT). SK-Electronics supplied KIT with tags, a reader with a very small antenna measuring about 1 centimeter (0.4 inch) in diameter, and software to interpret the read tag data. Researchers at KIT then included Hiroshima University in the pilot.

Kyoto Institute of Technology's Toshiharu Akino

Toshiharu Akino—who works at KIT's Center for Bioresource Field Science and is a KIT associate professor of animal communications, entomology and chemical biology—has spent the last year with his fellow researchers monitoring the behavior of carpenter ants, by saddling each one with an SK-Electronics UHF RFID tag (adhesively attached to its back), and installing reader antennas (also built by SK-Electronics) at the entrance to a foraging area, as well as at the nest's opening, each wired to a reader installed near the entrance. Once Akino began working with the technology, Hiraku Nishimori, a professor at Hiroshima University's graduate school of science department of mathematical and life sciences, joined the project in order to evaluate the data resulting from the early testing.