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RFID-Based Wireless Passive Sensors Utilizing Cork Materials

2015; IEEE Sensors Council; Volume: 15; Issue: 12 Linguagem: Inglês

10.1109/jsen.2015.2472980

1558-1748

Ricardo Gonçalves, Sergi Rima, Roberto Magueta, Pedro Pinho, Ana Collado, Apostolos Georgiadis, Jimmy Hester, Nuno Borges Carvalho, Manos M. Tentzeris,

Plant Surface Properties and Treatments

This paper presents the design of low-cost, conformal UHF antennas and RFID tags on two types of cork substrates: natural cork and agglomerate cork. Such RFID tags find an application in wine bottle and barrel identification, and in addition, they are suitable for numerous antenna-based sensing applications. This paper includes the high-frequency characterization of the selected cork substrates considering the anisotropic behavior of such materials. In addition, the variation of their permittivity values as a function of the humidity is also verified. As a proof-of-concept demonstration, three conformal RFID tags have been implemented on cork, and their performance has been evaluated using both a commercial Alien ALR8800 reader and an in-house measurement setup. The reading of all tags has been checked, and a satisfactory performance has been verified, with reading ranges spanning from 0.3 to 6 m. In addition, this paper discusses how inkjet printing can be applied to cork surfaces, and an RFID tag printed on cork is used as a humidity sensor. Its performance is tested under different humidity conditions, and a good range in excess of 3 m has been achieved, allied to a good sensitivity obtained with a shift of >5 dB in threshold power of the tag for different humid conditions.