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In-Plane Direct-Write Assembly of Iridescent Colloidal Crystals
Alvin T L Tan1, Sara Nagelberg2, Elizabeth Chang-Davidson2
1Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Small (Weinheim an Der Bergstrasse, Germany)
|December 31, 2019
Summary
Directly writing colloidal suspensions creates iridescent colloidal crystals in 2D patterns. This technique offers high speed and long-range order for advanced optical materials.
Area of Science:
- Materials Science
- Optics
- Nanotechnology
Background:
- Colloidal self-assembly yields materials with unique optical properties like photonic bandgaps.
- Existing colloidal crystal fabrication methods often involve complex, multi-step patterning processes.
Purpose of the Study:
- To present direct-writing as a simplified technique for fabricating colloidal crystals in arbitrary 2D patterns.
- To explore the potential for high-speed, ordered colloidal crystal synthesis.
Main Methods:
- Utilized convective assembly principles for direct-writing of colloidal suspensions.
- Optimized writing speed (≈600 µm s⁻¹) and process temperature (30 °C).
- Analyzed structural color via grating diffraction to deduce material properties.
Main Results:
- Achieved fabrication of iridescent colloidal crystals in arbitrary 2D patterns.
- Demonstrated long-range (cm-scale) order in the self-assembled colloidal crystals.
- Established a correlation between diffraction analysis and particle/grain characteristics.
Conclusions:
- Direct-writing offers an efficient, single-step method for creating patterned colloidal crystals.
- The technique shows promise for developing 3D printing of colloidal crystals.
- Insights gained can advance the fabrication of optical devices and materials.
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