Precise Control of Lyotropic Chromonic Liquid Crystal Alignment through Surface Topography

Area of Science:

• Materials Science
• Nanotechnology
• Soft Matter Physics

Background:

• Lyotropic chromonic liquid crystals (LCLCs) offer desirable anisotropic properties for applications like biosensors.
• Controlling the director field orientation in LCLCs has been a significant challenge.
• Existing methods lack the precision and versatility required for complex device fabrication.

Purpose of the Study:

• To introduce a straightforward strategy for arbitrary 2D orientation control of LCLC director fields.
• To demonstrate the fabrication of patterned LCLC alignments with high resolution.
• To explore the potential for 3D LCLC self-assembly using this technique.

Main Methods:

• Fabrication of surface topographical micro/nanostructures using two-photon laser writing.
• Utilizing pixelated designs of these structures to dictate LCLC alignment.
• Employing nanopillars for achieving patternable homeotropic alignment.

Main Results:

• Achieved precise control over LCLC alignment with a 2.5 μm pixel resolution.
• Demonstrated arbitrary 2D patterning, including the creation of a +2 topological defect.
• Successfully patterned homeotropic alignment using nanopillars.
• Showcased the potential for self-assembled 3D LCLC alignment.

Conclusions:

• The developed alignment strategy offers a simple and effective method for controlling LCLC director fields in 2D and 3D.
• This technique is compatible with conventional micro/nanofabrication methods.
• The findings open new avenues for manufacturing advanced liquid crystal-based electronic and biological devices.