Design and Optimization of Moldable Microstructures for Structural Color Generation

Harrell, Patrick A.

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https://hdl.handle.net/2142/17360 Copy

Description

Title

Design and Optimization of Moldable Microstructures for Structural Color Generation

Author(s)

Harrell, Patrick A.

Issue Date

2010-10-18T21:47:06Z

Director of Research (if dissertation) or Advisor (if thesis)

King, William P.

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• structural color
• micromachining
• micropatterning
• micromolding
• microembossing

Abstract

The use of structural color, common in nature, has been slow to catch on in manufacturing. Recent work has identified many of the structural features that lead to the advanced structural colors seen in nature, and some have even been successfully recreated. However most of these features are complex, three dimensional structures, making them difficult to manufacturing in a research environment, much less a standard manufacturing setting. However these advanced shapes are not strictly required for structural color – simple quasi-2D shapes of a single material are capable of producing simpler color and iridescence, without the manufacturing difficulties. These shapes are also capable of being embossed or molded into a single material, allowing for many mass production opportunities. To investigate the optical properties of these simple moldable microstructures, microstructured silicon masters were fabricated with a variety of features to examine six design parameters: shape, size, spacing, depth, tone (holes or pillars), and multilayer effects. These were then photographed under constant lighting at various rotation and tilt angles and analyzed for brightness and color data. This data identified what effects each design parameter had on the color, brightness, rotational viewing angle, and tilt viewing angle of the microstructured surface. Using this information, several conclusions were able to be drawn about the use of these microstructured surfaces for optical effects. The ridge density between features, feature side orientation, and the depth were all shown to have major effects on the optical properties. In addition, limited color control was demonstrated. The lessons learned were then summarized in a set of design guidelines to assist a researcher or product designer in developing a microstructure with specific optical characteristics.

Graduation Semester

2009-12

Permalink

http://hdl.handle.net/2142/17360

Copyright and License Information

Copyright 2009 Patrick A. Harrell

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