JEDDAH – Researchers at Saudi Arabia's King Abdullah University of Science & Technology (KAUST) are looking to further develop logic circuits that could be used for tracing banknotes in future. The radio frequency identification (RFID) systems can be used just about anywhere, from clothing tags to food - anywhere that a unique identification system is needed. Some auto manufacturers use RFID systems to move cars through an assembly line. At each successive stage of production, the RFID tag tells the computers what the next step of automated assembly is. The new project should take up to three years to complete, said Husam Alshareef, an associate professor in material science and engineering at KAUST. Banknotes and security printing provide lots of potential applications for printed electronics. The KAUST project was able to prove that ferroelectric, non-volatile memories fabricated on a substrate as rough as a banknote could perform on par with those made on silicon. For passive RFID applications memories need to be non-volatile to retain data, even when there is no power to operate the device. To prepare the surface for electrode and active layer deposition a planarizing layer of polydimethylsiloxane (PDMS) was applied. The memory layers, which include polymer as opposed to metal electrodes, were fabricated by spin coating. A future challenge in developing an organic RFID device is making the technology compatible with printing processes, for the device to be reproducible in volume. Alshareef said printed RFID for protecting currency is a long way off and envisages other nearer-term applications, such as sensing and smart tags for temperature tracking of certain foods. As the work progresses, KAUST has technology transfer and incubator facilities to support start-ups developing new R&D. Counterfeiting of banknotes is an ongoing problem for central banks and governments. RFID, especially printed or organic RFID, has been earmarked as a potential traceability technology for applying directly to currency within security printing and production processes. But numerous issues, such as device performance, integrity, durability and scalability mean it will be many years before banknotes use such technology, said Wolfgang Mildner, founder of PolyIC in Germany. One of the key differences between RFID and bar code technology is RFID eliminates the need for line-of-sight reading that bar coding depends on. Also, RFID scanning can be done at greater distances than bar code scanning. High frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer transmission ranges of more than 90 feet, although wavelengths in the 2.4 GHz range are absorbed by water (the human body) and therefore has limitations. Deploying a radio frequency identification system involves a lot more than purchasing the right tags and installing the right readers. To get business value from the all of the information collected, companies will need middleware to filter the data. They may need to upgrade enterprise applications and integrate it with RFID middleware. Each component will have up-front costs and some unexpected costs. Proximity (short range) and Vicinity (long range) are two major application areas where RFID technology is used. Track and trace applications are long range or vicinity applications. This technology provides additional functionality and benefits for product authentication. Access control applications are Short range or proximity type of applications. Static or in-motion assets tracking or locating, like a healthcare facility. – SG
