RFID - Radio Frequency Identification
petronella.norberg@acreo.se
The great challenge with RFID is to reduce the cost in order to be able to go to the item level tagging.
The term RFID (radio frequency identification) describes the automatic identification of tagged items by use of radio frequency signals. RFID also covers technologies above and below the traditional RF range, which work in a similar way. An RFID system typically consists of many data tags and one or more readers for wireless interrogation and writing to the tags. There are many applications for RFID – track and trace of goods in the logistic chain, waste managing, access control and authentication to mention a few.
The idea to tag all items around us and connect them to Internet has been around for a while and is often referred to as “The Internet of things”. Some initiatives have already been made aiming at this goal. One of them is the development of the electronic product code (EPC), which gives every item its unique code. Besides, some retail giants, such as Wal-Mart Stores, Tesco and Metro now require their suppliers to use RFID to tag all pallets. The remaining step, to tag all items, is however huge. Several problems are to be solved – privacy and payment issues, but also the handling of the enormous amount of data generated.
The diagram (in the PDF) shows the cost reduction evolution necessary in order to motivate RFID-tagging of different categories of “packages”. Note that printed fully organic tags fulfilling today’s standards are so far not available, although many R&D groups are striving to make this possible. Although the printing technology is very promising for the organic RFID with substantial cost reduction at hand, much improvement of the properties is necessary in order to compete with Si-chip based RFID in functionality. Huge resources are also invested in reducing the cost for tags based on “standard” Silicon and antenna technologies.
RFID at Acreo
RFID provides a seemingly endless supply of applications for low-cost electronics produced in large volumes. Many of these applications involve packages, tickets, plastic cards and other items with surfaces that can be used as printing substrates. Acreo has therefore selected RFID as one of its key application fields for reel-to-reel produced electronics. Focus is set on chipless technologies. The aim is not to compete with advanced chip solutions, but to provide low-cost alternatives. With all-printed tags, ID functionality is added at very low cost. Tagging can be integrated in the package line, which results in a cost for each tag – including assembly – of ~$0,001. A demonstrator of one of our technologies in the form of a board game is shown in the PDF. One advantage with the all printed tags is that the active print can be overwritten with graphics. This can be a decorative print, a user instruction, a barcode, a name tag or other.
Together with Stora Enso, M-real and Agfa, Acreo has developed an electrochemical memory based on organic logic circuits. The memory only needs external powering for its operation and it is fabricated by plotter equipment, printing technologies and lamination.
The cost for an RFID tag is often estimated to be equally divided by the chip, the antenna and the assembly of the two. It is therefore of interest to find low-cost alternatives to etched antennas. Acreo has developed a method for the dry phase patterning (DPP) of aluminum laminates reel-to-reel. The technology substitutes wet etching methods and is considered more environmentally friendly. Reel-to-reel patterning of aluminum at high speed with low environmental load opens for low-cost fabrication of antennas.
Acreo’s competence covers the whole range of RFID solutions, from chipless low-cost technologies to design of wireless systems, integrated circuits and integrated antennas and packaging. Acreo’s organic and electrochemical devices include displays, sensors and conducting lines. These can be combined with silicon electronics and the potential in having the best of these two worlds should not be overlooked.