Development of soft actuator operated by dual frequency mode using spherical liquid crystal elastomers

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05656
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Ritsumeikan University
• Principal Investigator: Kaneko Kosuke 立命館大学, 生命科学部, 助教 (30469192)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 液晶 / エラストマー / フローフォーカシングデバイス

Outline of Final Research Achievements

Dual frequency liquid crystals (DFLCs) show different dielectric anisotropy depending on the frequency of the applied AC electric field. Therefore, the molecular orientation of DFLCs can be controlled by changing the frequency. This study aims to prepare the spherical liquid crystalline elastomers showing the DFLC property and investigate the shape changes of the spherical LC elastomers under the varied frequencies of the AC electric field.
First, a nematic LC molecule containing a double bond at the end of an alkyl chain was synthesized based on the molecular structure reported to exhibit dual frequency characteristics. The compound obtained and a crosslinker having a thiol group were mixed at an appropriate ratio, and a thiol-ene reaction was carried out to synthesize spherical LC elastomers by using a flow-focusing device. After clarifying the phase transition behavior of the LC elastomers obtained, the shape change under DC and AC electric fields was observed.

Free Research Field

材料化学

Academic Significance and Societal Importance of the Research Achievements

本研究では二周波駆動液晶の基礎的研究を完成し、二周波駆動性を利用した新しいアクチュエータ材料の創製や液晶ブレーキへの実用化に展開するための基盤となる研究を行う。
従来型の電場のON・OFFによる刺激応答は、外場による一方向への応答性(電場ON)を利用した原理であるため、逆方向への応答(電場OFF)については駆動力が働いていない。本研究は、印加交流電場の周波数の違いによって異なる誘電率異方性を示す二周波駆動液晶を用い、周波数の変化により棒状液晶分子の配向を制御して球状エラストマーの形状変化を促す、本質的な意味でのスイッチング機能を利用する新たな試みである。