Example：10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
An Ultra-Sensitive Lorentz Microwave Sensor for Detection of Low-Permittivity Gaseous Water States and Sub-Wavelength Biosamples IEEE Sensors Journal (IF3.301), Pub Date : 2021-09-22, DOI: 10.1109/jsen.2021.3114625 O. Siddiqui, M. Shah, M. Amin, R. Ramzan, M. Harun, H. F. Abutarboush
The high sensitivity of Lorentz sensors comes from its narrowband resonant characteristics marked by rapid slope change of slope of its phase spectrum, a phenomenon known as Anomalous dispersion. Unlike conventional microwave resonant sensors which have a resonant amplitude, the Lorentz sensors also have unique signature in its phase spectra which adds a second degrees of freedom in detection and removes ambiguity in the identification of the resonant frequency. We demonstrate two sensing applications in which ultra-high sensitivity is required. In particular, we show that by exploiting the high electric field regions in Lorentz resonators detection of low density gaseous water states (steam) and sub-wavelength sized biomaterials is possible. The material sensing is performed by characterizing the resonant shifts in the frequency range of 1 to 2 GHz. Depending on the gaseous state concentrations, the dielectric constant of the detected steam lies between 1.04 and 1.6 GHz. The Lorentz resonator is shown to distinguish accurately between different sub-wavelength samples derived from different parts of chicken. We anticipate that the proposed sensor can be used in biosensing of cancerous cells and in detecting low-permittivity poisonous gaseous matter such as clear smoke, carbon mono oxide, methane and nitrogen.