Tailoring surface patterns to direct the assembly of liquid crystalline materials

ABSTRACT

Molecular ordering and the defect structures of a material play essential roles in its function and performance. Controlling molecular alignment and topological defects has been a cornerstone in the field of liquid crystalline (LC) materials. Here, we present an overview of different methods to tailor surface chemistry and surface topography in order to direct the assemblies of LCs, leading to complex morphologies of topological defects. We detail various top-down patterning techniques in specific LC systems, including small molecule nematic and smectic LCs, and LC polymers (LCPs), and their roles in discoveries of new phenomena, new materials, and new applications. We close the review with a prospective on the potential impact of the LC patterning efforts to fundamental understanding, advancement of new materials and new phenomena, and potential technological applications.

KEYWORDS:

• Nematic liquid crystals
• smectic liquid crystals
• liquid crystal polymers
• topological defects
• liquid crystal alignment
• surface patterns

Acknowledgements

The authors acknowledge Randall D. Kamien for critical reading of the manuscript. They are grateful of the collaborations with Randall D. Kamien, Kathleen J. Stebe, and Russell J. Composto at University of Pennsylvania, Dae Seok Kim and Dong Ki Yoon at KAIST, and many former students and postdoctoral fellows, including Daniel Beller, Mohamed Amine Gharbi, Francesca Serra, Elaine Lee, Marcello Cavallaro Jr., Robert C. Ferrier Jr., and Gerardo Cedillo-Servin, who contributed to the work cited here.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Yu Xia http://orcid.org/0000-0002-5393-059X

Shu Yang http://orcid.org/0000-0001-8834-3320

Additional information

Funding

The authors acknowledge funding from National Science Foundation (NSF) through the University of Pennsylvania's Materials Research Science and Engineering Center (MRSEC) (DMR-1720530 and DMR-1120901), DMR/Polymer program (DMR-1410253) and [Emerging Frontiers in Research and Innovation program (EFRI) ODISSEI grant (EFRI 13-31583)].