Research Abstract


Large-scale self-organization of reconfigurable topological defect networks in nematic liquid crystals

2016年11月7日 Nature Communications 7 : 13238 doi: 10.1038/ncomms13238



Yuji Sasaki, V.S.R. Jampani, Chiharu Tanaka, Nobutaka Sakurai, Shin Sakane, Khoa V. Le, Fumito Araoka and Hiroshi Orihara

Corresponding Authors

V.S.R. Jampani
理化学研究所 創発物性科学研究センター

荒岡 史人
理化学研究所 創発物性科学研究センター

折原 宏
北海道大学大学院 工学研究院 応用物理学専攻

Topological defects in nematic liquid crystals are ubiquitous. The defects are important in understanding the fundamental properties of the systems, as well as in practical applications, such as colloidal self-assembly, optical vortex generation and templates for molecular self-assembly. Usually, spatially and temporally stable defects require geometrical frustration imposed by surfaces; otherwise, the system relaxes because of the high cost of the elastic energy. So far, multiple defects are kept in bulk nematic liquid crystals by top-down lithographic techniques. In this work, we stabilize a large number of umbilical defects by doping with an ionic impurity. This method does not require pre-patterned surfaces. We demonstrate that molecular reorientation controlled by an AC voltage induces periodic density modulation of ions accumulated at an electrically insulating polymer interface, resulting in self-organization of a two-dimensional square array of umbilical defects that is reconfigurable and tunable.