Erythema induced by ultraviolet (UV)B light is a common skin reaction. Currently, three techniques, the Chromameter(®) CR-400, the Mexameter(®) MX16 and full-field laser perfusion imaging (FLPI), are widely used for dermatological evaluation of UVB-induced erythema. However, there is little known about the comparative performance of these three techniques. This study was therefore designed to evaluate the effectiveness of the three techniques. Our findings showed that the performance of Chromameter and Mexameter for measurement of UVB-induced erythema was very similar, while FLPI indicated acute erythema at D1 with the greatest fold change. Further studies of UVB dose-dependence need to be carried out.
Vivid structural colors, inspired by butterflies, which can display iridescent colors dynamically when white light illuminates the surface with subwavelength period ripples, have attracted significant interest for its potential application in the fields of information storage, anti‐counterfeiting, etc. However, there is still a huge demand for the development of multipattern dynamically transformable display surfaces using a versatile method. A new scheme based on femtosecond laser combined with variable polarization processing has been proposed. This scheme enables a surface with a structural color function that can be easily prepared by adjusting the polarization of the laser via a half‐wave plate. Four types of structural units with designated periodic orientations are written on the same sample to exhibit four different colorful images. Through experiment and analysis, it is demonstrated that different colors can be displayed by changing the observation angle, and a multi‐pattern display can be realized by rotating the sample. The lithography‐free inscribed patterns show a strong azimuthal angular sensitivity to color and its brightness. This work demonstrates that femtosecond laser surface structuring provides a versatile platform to create various micro/nanostructures on a solid surface, and this technique can be used for the biomimetic lithography‐free processing of any material using ablation.
We propose a high-precision method for the fabrication of variable focus convex microlens arrays on K9 glass substrate by combining femtosecond laser direct writing and hot embossing lithography. A sapphire master mold with a blind cylindrical hole array was prepared first by femtosecond laser ablation. The profile control of microlenses dependent on the temperature and the diameter of the blind hole in the sapphire mold was investigated. The curvature radius of the microlens decreased with temperature and increased with diameter. Uniform convex microlens arrays were fabricated with good imaging performance. Further, variable focus convex microlens arrays were fabricated by changing the diameter of the blind hole in sapphire, which produced the image at variable z planes. This method provides a highly precise fabrication of convex microlens arrays and is well suited for batch production of micro-optical elements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.