Organic RFID tag

RFID tags Organic conductors. Thick film Ag is used for... 

OFETs are the basis of all logie deviees that are required to eontrol, for example, the intensity of a display pixel (the so ealled all organic display) or the realisation of a radio frequeney identifieation (RFID) tag. Sinee for the latter applieations only limited frequeney bands are available (essentially 13.56 MHz or 900 MHz) this plaees rather strong eonstraints on the required switehing properties of the OFETs. 

K. Dimmler, Developments in printed RFID Tags , Proceedings of Organic Electronic Conference, Frankfurt (2006). 

Printed RFID-tags have already been demonstrated by companies active in the printed electronics industry. At the Organic Electronics Conference (OEC) 2007 in Frankfurt, in each conference-ticket an RFID-tag fabricated by Poly-IC (http //www.polyic.com) was incorporated [8]. 

Research is conducted in-house, as well as by a multitude of scientific cooperation partners, like universities and research institutes. Industrial partners include innovative companies like printed systems. Creavis participates actively in multiple European and BMBF-frnanced projects. The Nanomatch project (http //www.nanomatch.eu), in which new hybrid devices are developed, and the MaDriX project (http //www.madrix-projekt.de) that focuses on the development of printed RFID-tags, are just two examples. Next to such projects, Creavis is also a member of international research and development networks, like the Organic Electronics Association (OEA) and the Dutch Polymer Institute (DPI). Membership of these networks enables Creavis to keep a close eye on the market, in order to respond as fast as possible to new trends and demands. 

A second proposed use of organic semiconductors is in radio frequency ID (RFID) tags [11,12]. Several hurdles must be overcome in order to make organic RFID practical. The first is the transistor speed, which will only be adequate for... 

Given this general outline, it is now possible to examine the state of the art of organic transistors and identify the critical issues to be considered with regard to the realization of printed RFID tags. 

Environmental stability. Perhaps one of the biggest concerns with organic materials to date relates to their poor environmental stability. Most organic semiconductor materials are prone to degradation on exposure to oxygen and/or moisture. This will necessitate the development of robust encapsulation processes. This should be possible, however, since, unhke in OLEDs, optical transparency is not required for RFID tags, which dramatically opens up the range of candidate encapsulation materials. 

The surface resistivity of PEDOT PSS patterned using flexo printing is rather high, ranging from a few to 10 kfl/n. However, new inks are continually developed, and improved performance is expected. PolylC is also developing a flexo production line for RFID tags based on organic field-effect transistors. 

For all-printed thin film transistors (TFT), various organic and inorganic metal electrode materials, such as conductive polymer, carbon nanotube (CNT), organic metal compound, or metal nano-particles, have been used as gate and source/drain electrodes [6-11] in a combination with inkjet- and laser-based printing methods. One of the immediate applications for all-printed TFT would be flexible or rugged display backplane and disposable radio frequency identification (RFID) tags. In addition, printed metal electrodes and TFT have also been used to fabricate passive circuit components, power transmission sheets and sensors for ambient electronics and electronic skin [12-13]. 

The organic field effect transistor (OFET) acts essentially as an electronic valve by modulating the semiconductor channel conductance via the gate field. This device is essential in all electronic applications, including integrated circuits for memories and sensors and also to drive individual pixels in active matrix displays. Probably one of the most exciting applications of organic electronic circuits is in the supply chain area, where radiofrequency-powered elements (e.g. RFID tag) may replace ID barcodes for identification and be applicable as a backplane drive for displays. 

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