Nondestructive high-resolution microwave imaging of biomaterials and biological tissues

A high-Q near-field probe based on the 2D microstrip line geometry using defected ground structure (DGS) has been proposed and experimentally evaluated for nondestructive characterization and high-resolution imaging of biomaterials and biological tissues. The unique specifications of the probe are as follows; small size, simple fabrication, non-contact with a sample, excellent de-coupling from surroundings and high microwave power is directly coupled into the tissues. Experimental results show that the probe is able to detect the microwave characteristics of thin lossy biomaterials containing water. High resolution microwave images of leaves with different water content have been obtained with amplitude contrast of about 40–50 dB and spatial resolution of about λ/40. Also, a measurement scenario for detection of lipomas with different sizes has been investigated. Results show that the proposed probe can detect the lipoma of a size larger than 5 mm. Finally, an artificial model to detect skin cancer at the early stage is developed using layers of raw chicken skin. Measurement results show that the probe could accurately detect malignant tumor with at least 15 dB magnitude and more than 100° phase contrast from the healthy skin and with about 8 dB contrast from the benign lesions of the same size.