A Novel Conformal RFID-Enabled Module Utilizing Inkjet-Printed Antennas and Carbon Nanotubes for Gas-Detection Applications

Abstract

Abstract-This letter introduces for the first time the integration of a conformal radio frequency identification (RFID) antenna with a single-walled carbon nanotube (SWCNT) composite in a chipless RFID node for toxic gas detection. The electrical performance characterization of the inkjet-printed SWCNT film is also reported for the first time up to 1 GHz. The whole module is realized by inkjet printing on a low-cost paper-based substrate, and the RFID tag is designed for the European UHF RFID band. 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.

Nanotechnology Enables Wireless Gas Sensing

“…Figure 18. The power reflection coefficient of the RFID tag antenna with a single-walled nanotube film before and after the gas flow [16].…”

“…While many types of sensors that utilize the unique properties of CNTs have been proposed, most of them are based on direct contact, where the monitoring station and sensing unit are wired or can be wireless enabled through their integration with a wireless module. The difference between a wireless-enabled sensor and a wireless transducer of a physical parameter is that the former needs a separate RF module with a communication antenna [15], whereas the latter just utilizes the change of one or more microwave/electrical parameters, such as frequency shift, to directly indicate the change of one physical parameter of the environment such as pressure, temperature or gas concentration [3], [16]- [18]. These transducers are passive components, require much simpler processing circuitry, and they need only passive antenna/radiating structures for communication with the exciting reader.…”

“…There exist numerous gas sensors based on individual CNTs, bundles or aligned arrays of CNTs, such as solid-state or surface acoustic wave (SAW) sensors [10]- [16] at dc or low-frequency operation. However, this type of sensor suffers from higher cost and low repeatability, and, usually, a battery is required, leading to mostly active implementations.…”

Inkjet catalyst printing and electroless copper deposition for low-cost patterned microwave passive devices on paper

“…[1][2][3][4] Reports of inkjet-printed metalized devices on flexible substrates range from antennas to sensors to thin film transistors to RFID tags. [1,[5][6][7][8][9][10][11][12][13][14] The patterned metallization of substrates using inkjet printing is commonly conducted with inks comprised of a dispersion of metallic nanoparticles within a carrier fluid tailored to achieve a desired viscosity and wetting behavior for a particular substrate. [1][2][3][4] Coatings on the metallic nanoparticles are used to ensure that the nanoparticles remain well dispersed in the ink.…”

Wireless radio frequency detection of greatly simplified polymeric membranes based on a multifunctional ionic liquid

“…The ongoing drive for more sophisticated chemical sensing templates is based on not only the development of new materials [1,2], but also on the engineering of new sensing instrumentation and on how the information is retrieved [3,4]. The development of new sensing materials seems to be based on the use of single molecular probes capable of simultaneous determination of multianalytes [5,6], and also on simultaneous detection via multiple detection channels inherent to the material studied [7][8][9].…”