Robust topology design of periodic grating surfaces

Abstract

Modern nanoscale manufacturing techniques allow for a high degree of flexibility in designing surface microstructures and nanostructures. Injection molding of nanosized features allows for mass production of plastic components with a tailored nanostructure producing specific optical effects depending on the purpose. This work details the use of topology optimization for designing periodic polymer grating surfaces with complex optical properties. A method based on robust topology optimization is formulated for designing the nanostructure of plastic surfaces with extreme reflection or transmission properties. Topology optimization allows for free distribution of material but a mechanical constraint based on the fundamental free mechanical vibration frequency ensures connected structures. Several examples are given to illustrate the efficiency of the method.

Designing visual appearance using a structured surface

“…Our previous works [15,[17][18][19] focused on how to model and design dielectric structures for prescribed color responses in a systematic way. In this paper we focus on the sample production and verification steps and have therefore chosen to use a 50% duty cycle (half-pitch) line grating with a height of 215 nm as the unit structure for our structurally colored surface.…”

Inverse design of nanostructured surfaces for color effects

“…Numerical Model The numerical setup is similar to our previous study [12] but extended with a near-to far-field transformation as well as a color-conversion process. The computational domain is given in 2D and consists of three regions: an air region Ω A ; a design region Ω D ; and a bulk region Ω B , see Fig.…”

“…In previous studies [10][11][12], a method based on topology optimization [13] has been formulated for designing nanostructured surfaces with extreme reflection or transmission properties. Here we extend [12] by including a near-to farfield transformation of the reflected light and converting the scattered far-field spectrum to colors.…”

“…Here we extend [12] by including a near-to farfield transformation of the reflected light and converting the scattered far-field spectrum to colors. With this extension, we obtain a methodology based on topology optimization for designing nanostructured multilayered surfaces displaying prescribed structural color properties.…”

Design of structurally colored surfaces based on scalar diffraction theory

“…The design of such gratings can be seen as a special case (periodic and single frequency) of the optimization formulation developed in this work. To the best of the authors' knowledge the only other works exploring the possibilities of systematic design of surfaces with angular distributed colors are [21] and [22]. These papers consider more complex distributions of material based on the topology optimization approach (c.f.…”