A Review on Passive and Integrated Near-Field Microwave Biosensors

Abstract

In this paper we review the advancement of passive and integrated microwave biosensors. The interaction of microwave with biological material is discussed in this paper. Passive microwave biosensors are microwave structures, which are fabricated on a substrate and are used for sensing biological materials. On the other hand, integrated biosensors are microwave structures fabricated in standard semiconductor technology platform (CMOS or BiCMOS). The CMOS or BiCMOS sensor technology offers a more compact sensing approach which has the potential in the future for point of care testing systems. Various applications of the passive and the integrated sensors have been discussed in this review paper.

Design and Fabrication of a BiCMOS Dielectric Sensor for Viscosity Measurements: A Possible Solution for Early Detection of COPD

“…In this design, the capacitive elements are a pair of microstrip open-stubs with an electrical length below the quarter-wavelength of the sensor operation frequency, as shown in Figure 3 a. The operation frequency of the sensor is in the range of 30 GHz, which results in a high SNR [ 17 ]. Similar to the previous sensor, the 250 nm SiGe:C BiCMOS technology of IHP was used to fabricate the sensor.…”

“…Silicon-based technologies such as CMOS provide countless advantages for POC and Internet-of-Things (IoT) applications such as miniaturization, portability, high accuracy, reliability, low cost, high noise immunity, low power consumption, and complete integration with Lab-On-a-Chip (LOC) [ 15 ]. Due to these advantages, CMOS-based dielectric sensors have been used in numerous biological applications such as microorganism detection and characterization, neuronal activity detection, dielectric spectroscopy for medical diagnosis, and disease detection [ 16 , 17 , 18 ]. The developed biosensors detect and characterize biological targets based on their intrinsic properties or biochemical reactions.…”

“…The developed biosensors detect and characterize biological targets based on their intrinsic properties or biochemical reactions. These biological parameters include biomarkers, biomolecules, proteins, DNA, pathogenic organisms, hormones, medical analytes such as glucose, and medical parameters like blood pressure [ 17 , 18 ]. For example, CMOS-based electrochemical sensors have been designed and developed for DNA detection and characterization [ 19 , 20 , 21 ].…”

“…The capacitance change of the sensor affects the free oscillation frequency of the LC resonant tank which would be used for the readout mechanism. The operating frequency of the sensor is chosen to be in the range of 10–30 GHz, where the permittivity of water is considerably high compared to other existing biomaterials in the sputum [ 17 ]. Due to the existing permittivity contrast in the mentioned frequency range, a better Signal-to-Noise Ratio (SNR) is expected.…”

“…Furthermore, the mentioned frequency range provides the most accurate results for dielectric sensing applications considering the fact that the undesired parameter-dependent dispersion mechanism of the biological cells, which exists in low-frequency ranges, has negligible effects on the sensor functionality. On the other hand, based on the single Debye’s relaxation mechanism, the dielectric permittivity of water decreases after 17 GHz making extremely high frequency measurements inadequate for the intended application [ 17 ].…”