title: Supercritical Fluid-Driven Polymer Phase Separation for Microlens with Tunable Dimension and Curvature.
abstract: Microlenses are highly sought as reliable means for high-resolution optical imaging at low illumination intensities. Plano-convex configuration with tunable dimension and curvature is an essential feature in the microlens fabrication. In this study, we present a facile and green route for preparing well-defined microlenses based on polymer phase separation in the presence of supercritical carbon dioxide (scCO2). The behaviors of linear polymethylmethacrylate protruded from cross-linked silicone network in scCO2 environment are investigated from the perspectives of thermodynamics and kinetics. Microlenses with dimensions from 2 to 15 μm and contact angles from 55° to 112° are successfully obtained through the adjustment of the kinetic conditions and outgassing rate. With the tunable focal length, they exhibit intrinsic function of discerning submicroscale patterns that are unable to be observed directly under optical microscope. Moreover, size confinement on the substrate results in the generation of well-ordered microlens arrays, affording great promise for applications in bioimaging, photolithography, light harvesting, and optical nanosensing.
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Youdi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Xinyue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Fuze
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Yapei
authors.initials: Y
authors.lastname: Wang
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D006801:Humans; D007909:Lenses; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000627:therapeutic use; D019904:Polymethyl Methacrylate / Q000138:chemical synthesis* / Q000737:chemistry; D014786:Vision Disorders / Q000517:prevention & control*
chemical_list: D011108:Polymers; D002245:Carbon Dioxide; D019904:Polymethyl Methacrylate
keywords: microlens; microlens array; polymer phase separation; supercritical carbon dioxide; variable focal length