Unidirectionally aligned line patterns driven by entropic effects on faceted surfaces

Sung Woo Hong, June Huh, Xiaodan Gu, Dong Hyun Lee, Won Ho Jo, Soojin Park, Ting Xu, Thomas P. Russell

Research output: Contribution to journalArticlepeer-review

86 Citations (Scopus)


A simple, versatile approach to the directed self-assembly of block copolymers into a macroscopic array of unidirectionally aligned cylindrical microdomains on reconstructed faceted single crystal surfaces or on flexible, inexpensive polymeric replicas was discovered. High fidelity transfer of the line pattern generated from the microdomains to a master mold is also shown. A single-grained line patterns over arbitrarily large surface areas without the use of top-down techniques is demonstrated, which has an order parameter typically in excess of 0.97 and a slope error of 1.1 deg. This degree of perfection, produced in a short time period, has yet to be achieved by any other methods. The exceptional alignment arises from entropic penalties of chain packing in the facets coupled with the bending modulus of the cylindrical microdomains. This is shown, theoretically, to be the lowest energy state. The atomic crystalline ordering of the substrate is transferred, over multiple length scales, to the block copolymer microdomains, opening avenues to large-scale roll-to-roll type and nanoimprint processing of perfectly patterned surfaces and as templates and scaffolds for magnetic storage media, polarizing devices, and nanowire arrays.

Original languageEnglish
Pages (from-to)1402-1406
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number5
Publication statusPublished - 2012 Jan 31
Externally publishedYes


  • Block copolymer
  • Directed self-assembly
  • Long-range order
  • Pattern transfer

ASJC Scopus subject areas

  • General


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