A microwave biosensor based on spoof surface plasmon polaritons for in vivo measurement of the water content of human skin tissues

This paper demonstrates a microwave biosensor, based on the spoof surface plasmon polaritions (SSPPs) excited by a planar plasmonic waveguide, which can measure in vivo the water content of human skin tissues timely and accurately. A SSPPs biosensor is fabricated and measured using the vector network analyzer using a human finger as a real model. Experimental results of the biosensor with/without normal human finger skin tissues and pure water have a good agreement with our simulation. The SSPPs biosensor has potential applications for the areas of in vivo measurement of the human stratum corneum water content with topical cosmetics, early diagnostics of superficial tumors such as malignant melanoma and lymphatic cancer, and also in the guiding tumors resection.