### Abstract

We present our recent theoretical and numerical studies concerning the properties of cholesteric blue phases (BPs). One is on the effect of the variation of the Frank elastic constants on the stability of BPs. Our study is based on a classical and well-known theory of Meiboom et al. that gave a rough estimate of the temperature range of stable BPs in the case of equal elastic constants. We extend it to take into account the difference of the elastic constants. We show that the stability of BPs is greatly enhanced when the bend elastic constant K_{33} is smaller, which agrees well with recent experiments. We also show that larger splay (K_{11}) and twist (K _{22}) elastic constants are also favorable for the stability of BPs. The other subject of the present paper is the response of BPs in a parallel cell to an applied electric field. We carry out numerical calculations for the investigation the dynamics of orientational order and associated disclination lines. Our calculations are based on a Landau-de Gennes theory describing the orientational order of the liquid crystal by a second-rank tensor. Our preliminary calculations demonstrate that a non-uniform electric field induced by comb-like electrodes gives rise to non-trivial dynamics of disclination lines.

Original language | English |
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Title of host publication | Liquid Crystals XVI |

DOIs | |

Publication status | Published - Dec 1 2012 |

Externally published | Yes |

Event | Liquid Crystals XVI - San Diego, CA, United States Duration: Aug 12 2012 → Aug 15 2012 |

### Publication series

Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 8475 |

ISSN (Print) | 0277-786X |

### Other

Other | Liquid Crystals XVI |
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Country | United States |

City | San Diego, CA |

Period | 8/12/12 → 8/15/12 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering

### Cite this

*Liquid Crystals XVI*[84750T] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8475). https://doi.org/10.1117/12.929315

**Theory and simulation of cholesteric blue phases : Effect of the elastic constants on the stability of blue phases and the response of a blue phase cell to an electric field.** / Fukuda, Junichi.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Liquid Crystals XVI.*, 84750T, Proceedings of SPIE - The International Society for Optical Engineering, vol. 8475, Liquid Crystals XVI, San Diego, CA, United States, 8/12/12. https://doi.org/10.1117/12.929315

}

TY - GEN

T1 - Theory and simulation of cholesteric blue phases

T2 - Effect of the elastic constants on the stability of blue phases and the response of a blue phase cell to an electric field

AU - Fukuda, Junichi

PY - 2012/12/1

Y1 - 2012/12/1

N2 - We present our recent theoretical and numerical studies concerning the properties of cholesteric blue phases (BPs). One is on the effect of the variation of the Frank elastic constants on the stability of BPs. Our study is based on a classical and well-known theory of Meiboom et al. that gave a rough estimate of the temperature range of stable BPs in the case of equal elastic constants. We extend it to take into account the difference of the elastic constants. We show that the stability of BPs is greatly enhanced when the bend elastic constant K33 is smaller, which agrees well with recent experiments. We also show that larger splay (K11) and twist (K 22) elastic constants are also favorable for the stability of BPs. The other subject of the present paper is the response of BPs in a parallel cell to an applied electric field. We carry out numerical calculations for the investigation the dynamics of orientational order and associated disclination lines. Our calculations are based on a Landau-de Gennes theory describing the orientational order of the liquid crystal by a second-rank tensor. Our preliminary calculations demonstrate that a non-uniform electric field induced by comb-like electrodes gives rise to non-trivial dynamics of disclination lines.

AB - We present our recent theoretical and numerical studies concerning the properties of cholesteric blue phases (BPs). One is on the effect of the variation of the Frank elastic constants on the stability of BPs. Our study is based on a classical and well-known theory of Meiboom et al. that gave a rough estimate of the temperature range of stable BPs in the case of equal elastic constants. We extend it to take into account the difference of the elastic constants. We show that the stability of BPs is greatly enhanced when the bend elastic constant K33 is smaller, which agrees well with recent experiments. We also show that larger splay (K11) and twist (K 22) elastic constants are also favorable for the stability of BPs. The other subject of the present paper is the response of BPs in a parallel cell to an applied electric field. We carry out numerical calculations for the investigation the dynamics of orientational order and associated disclination lines. Our calculations are based on a Landau-de Gennes theory describing the orientational order of the liquid crystal by a second-rank tensor. Our preliminary calculations demonstrate that a non-uniform electric field induced by comb-like electrodes gives rise to non-trivial dynamics of disclination lines.

UR - http://www.scopus.com/inward/record.url?scp=84872162770&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84872162770&partnerID=8YFLogxK

U2 - 10.1117/12.929315

DO - 10.1117/12.929315

M3 - Conference contribution

SN - 9780819491923

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Liquid Crystals XVI

ER -