Organic RFID Tags

In this chapter, we investigate the potential of organic RFID tags as a product label. The primary market for organic RFID tags could be barcode replacement, i.e. tags that generate a fixed code sequence when powered by an RF field. We infer this from the current state of the art of the technology: code generators that generate code sequences up to 128 bit are possible in organic electronics (Myny et al., 2009) and chips comprising 414 organic-based thin-film transistors (OTFTs) can today be integrated into fully functional organic RFID tags with HF communication frequency of 13.56 MHz (Myny et al., 2009). More complex RFID embodiments that comprise e.g. encryption, re-programmable code stored in a non-volatile memory, and true bi-directional communication with a reader are beyond the current stateof-the-art of organic electronics, but can be envisioned in a more distant future. With 64 bit of data, that is read out in 10 to 20 ms, a realistic electronic tag for item-level identification can carry and read out the standard Electronic Product Code (EPC, http://www.epcglobalinc.org/). We have shown that these requirements to the complexity of the chip and the clock frequency can be obtained. We further assume that product identification tags should preferably be passive tags, that do not include a battery, since the integration of a battery would considerably increase the cost of a tag. Passive tags are powered by the electromagnetic field of the reader, also called interrogator. To power passive organic RFID tags, high-quality organic rectifiers are needed and these need to be very carefully designed. We have been able to obtain sufficient DC voltage to power organic code generators by organic rectifiers, using reader fields that comply with the standards imposed by the safety rules concerning electromagnetic radiation. Several research groups have published research results on organic RFID systems. In 2007, Cantatore et al. published a capacitively-coupled RFID system where a 64-bit code was read out at a base carrier frequency of 125 kHz (Cantatore et al., 2007). The 64-bit code generator Source: Radio Frequency Identification Fundamentals and Applications, Design Methods and Solutions, Book edited by: Cristina Turcu, ISBN 978-953-7619-72-5, pp. 324, February 2010, INTECH, Croatia, downloaded from SCIYO.COM