3D Printing-Enabled Near-Field Probe for Millimeter-Wave Skin Cancer Tumor Imaging

A novel 3D-printed microwave probe operating in the 25-45 GHz frequency range is designed and fabricated for early skin tumor detection using signal processing. Due to the highly lossy nature of the skin, electromagnetic wave penetration is difficult. To overcome this limitation, a multi-section probe design was developed to enhance wave penetration into the skin layer. This design effectively mitigates the effects of high-loss tangents in tissues and compensates for the small size of tumors, aiding in early detection. The probe's performance is validated through simulations and experimental measurements, showing excellent agreement. For imaging evaluation, a phantom model composed of pork skin, measuring 30 mm × 30 mm with a skin thickness of 4 mm, is utilized. A total of 215 scanning points were analyzed, and time-domain reflection waves were extracted, demonstrating the probe's ability to detect variations in tissue properties accurately. These signals were then processed using an entropy-based method. The reconstructed images across various scenarios highlight the effectiveness of the proposed probe in achieving high-resolution microwave imaging, indicating its strong potential for non-invasive, early-stage tumor detection.