Experimental analysis of selectivity and dynamic ranges of passive UHF-RFID chemical sensors

Antennas doped with Chemical Interactive Materials (CIM) have been recently proposed as wireless chemical sensors suitable to integration with the battery-less UHF Radiofrequency Identification (RFID) technology. The open critical issue of this class of devices is the specificity of the electromagnetic response to volatile compounds different than those they were proposed for. This contribution describes a chemical/electromagnetic experimental procedure to investigate the response of both already experimented and new CIMs to a range of common volatile compounds by exploiting the unique features of RFID links. The experimental campaign permitted to select four CIMs that are sensitive to humidity, ammonia, ethanol and octane with different dynamic ranges and complementarity, giving the base to develop future battery-less radio-electronic noses with the possibility of remote interrogation.