Abstract
Human masks are considered the mainstay in air filtration and purification technologies and against the spreading of bacterial and viral infections. This paper introduces a novel design of a human mask to increase the ultraviolet germicidal irradiation effect on pathogens. The proposed design consists of a tube with an annular photonic crystal (APC) attached to the mask's orifice, and a UV source is located in the tube's center. The main role of this study is the enhancement of UV doses based on the reflectivity of the proposed APC. Therefore, increasing pathogens' inactivation level in the incoming air to the mask's orifice could be investigated. The numerical investigations demonstrated that the proposed APC could provide a complete photonic bandgap with a high reflectivity in the wavelength regime from 207 to 230 nm. In addition, we have considered the roles of the thickness of layers, inner core radius, and the azimuthal number. Meanwhile, the results showed the ability to use a wide range of core radius values without almost any variations in the optical properties of the proposed design. Such results could grant the advantage of using this design by the manufacturing of human masks with different sizes besides the inclusions in other ultraviolet germicidal irradiation applications.