Creation of isotropic liquid crystals by intentionally introducing 3D topological defects

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21975
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Osaka University
• Principal Investigator: OZAKI Masanori 大阪大学, 工学研究科, 教授 (50204186)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 液晶 / 配向欠陥 / 光学的等方性 / ウォール欠陥

Outline of Final Research Achievements

The liquid crystal originally forms a uniform molecular orientation state. In this research, we intentionally and controlledly introduced three-dimensional topological defects in liquid crystals, and explored the possibility of creating a new liquid crystal order and its application. That is, by actively utilizing and controlling the alignment field mismatch (topological defect) in the liquid crystal, which has been conventionally excluded as harmful and unnecessary, We aimed to artificially realize the optically isotropic liquid crystal order that has been formed in a limited environment. Using the local photo-alignment technique, the wall defect structures were generated and stabilized, and the state transitions were performed by applying their electric fields.

Free Research Field

電子工学

Academic Significance and Societal Importance of the Research Achievements

従来、有害なもの不要なものとして排除されてきた液晶内のトポロジカル欠陥を積極的に活用・制御することにより、これまで自然界ではごく限られた条件下でのみ現れていた等方的な液晶秩序を人工的に発現させることは独創的で学術的に意義がある。すなわち、液晶は一様配向するべきもので光学的異方性媒質であるという従来の液晶の描像を覆す発想に基づいている。この様なデバイスの実現により、従来の液晶デバイスにおいて不可欠であった偏光子が不要となり、分子の初期配向プロセスも不要となり、しかも従来の液晶デバイスに比べ応答速度が二桁高速な光デバイスが期待できる。