n inkjet-printed, fully passive sensor capable of either humidity or gas sensing. The sensor is composed of an interdigitated electrode, a customized printable gas sensitive ink and a specialized dipole antenna for wireless sensing. The interdigitated electrode printed on
a paper substrate provides the base conductivity that varies during the sensing process. A fast response time of 3 min is achieved at room temperature for a H2S concentration of 10 ppm at a relative humidity (RH) of 45%. The passive wireless sensing is enabled through an antenna in which the inner loop takes care of conductivity changes in the 4–5 GHz band, whereas the outer-dipole arm
is used for chipless identification in the 2–3 GHz band.
More details can be found at:
Abdul Quddious , Munawar M. Khan , Farooq A. Tahir, Shuai Yang, Atif Shamim, Khaled N. Salama, Hammad M. Cheema, Disposable, Paper Based and Inkjet-Printed Humidity and H2S Gas Sensor for Passive Sensing Applications, Sensors 2016, 16, 2073; doi:10.3390/s16122073