Micromachined near-field millimeter-wave medical sensor for skin cancer diagnosis

This paper presents the recent achievements in a project on micromachined millimeter-wave near-field medical sensors, in particular for skin cancer diagnosis. Micromachining enables sensor probes which achieve both high sensitivity and high lateral resolution through a drastically miniaturized probe tip. Two different design strategies are investigated: a broad-band, non-resonating, tapered dielectric-rod probe, and a resonance slot sensor. For probe characterization micromachined silicon test and calibration samples with tailor-made permittivity were fabricated. Characterization of fabricated prototypes show that the tapered probe can clearly and reproducibly distinguish silicon test samples of permittivity corresponding to healthy and cancerous skin tissue at 100 GHz. For the resonance slot probe the simulated response to materials of different permittivity is shown. Furthermore, the paper presents the design of phantom materials for probe evaluation on soft-matter dielectrics.