Fabrication and Encapsulation Processes for Flexible Smart RFID Tags

RFID tags are often envisioned as a replacement for the current barcodes. These systems are simple wireless transponders with integrated memory chips. Nowadays the challenge in this field is the integration of sensors on board and there are some examples of tags in the market including temperature and humidity sensors (Opasjumruskit et al. 2006). However, there are no commercial labels containing chemical sensors. In this chapter book, we present an integrated process flow for the integration of gas sensors onto flexible substrates together with a RFID transponder to get a Flexible Tag Microlab (FTM) innovative system for food logistic applications (see figure 1). In the proposed scenario, the FTM is designed to be handled by a specifically designed reader with onboard sensing capabilities (Vergara et al. 2007). RFID technology in the 13.56 MHz band was chosen since it is the best compromise for integration on a flexible tag. Furthermore this band is very suitable for the food logistic application, considering possible constraints such us the surrounding environment (e.g. humidity) and range of communication. In order to be compliant with recent RFID developments the ISO 15693 standard has been selected.