Capacitive Contact Imaging For Skin Characterization

Capacitive contact imaging has shown potential in measuring skin properties including skin hydration and skin texture. Our previous studies showed it also can be used for solvent penetration measurements, skin damage assessments, as well as hair and nail water content measurements, despite the low water content. Through calibration we also measure the absolute permittivity of the skin, and from absolute permittivity we then work out the absolute water content (or solvent content) in skin. In this paper, we present our latest study of skin characterization, i.e. dry skin, hydrated skin, sweating, and damaged skin etc., using a commercial contact imaging system, the Epsilon (Biox Systems Ltd, England). We will first present the theoretical background and measurement principles, then illustrate the Epsilon calibrations. We will use experimental results to illustrate how the contact images can be used for skin characterization. Through image processing we can focus on the area that we are interested and eliminate the areas that we are not. We will also show latest results on skin solvent penetrations, and how to calculate the absolute solvent content in skin and diffusion coefficient of the solvent.