A Novel Conformal Wireless Sensor Utilizing Inkjet-printed RFID and Carbon Nanotubes for Gas Detection
L. Yang, M. Tentzeris
Georgia Institute of Technology, US
Keywords: Carbon nanotube composites, RFID, conformal antennas, gas sensing, inkjet printing, wireless sensor
Abstract:This invention introduces for the first time the integration of a conformal RFID antenna with a Single Walled Carbon Nanotube (SWCNT) composite in a chipless RFID node for toxic gas detection. A SWCNT film fabrication recipe is developed, and an RFID antenna configuration is proposed. The developed inkjet-printed SWCNT film has stable electrical performance up to 1 GHz, as the first ever type in its kind. The whole module is realized by inkjet printing on a low-cost paper-based substrate and can be fabrictated together with the RFID tag during the inkjet printing process. The electrical conductivity of the SWCNT film changes in the presence of very small quantities of toxic gases like ammonia and nitrogen oxide, resulting in the variation of the backscattered power level which can be easily detected by the RFID reader to realize reliable wireless toxic gas sensing. The invention demonstrated the great applicability of inkjet-printed CNT for the realization of fully-integrated “green” wireless RFID-enabled flexible sensor nodes based on the ultrasensitive variabiliity of the resistive properties of the CNT materials, and will ultimately reduce the manufacturing cost of the wireless gas sensors.