Investigation of the dynamics of graphene-doped liquid crystals for high power vibration energy harvesting

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K14678
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 20010:Mechanics and mechatronics-related
• Research Institution: The University of Tokyo
• Principal Investigator: Miyoshi Tomoya 東京大学, 大学院工学系研究科(工学部), 特任助教 (90809641)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 液晶 / 振動発電 / グラフェン

Outline of Final Research Achievements

Liquid crystals, which possess both dielectric anisotropy and flow properties, have attracted much attention in recent years for their application in MEMS transducers. As an example, while inserting nematic liquid crystals between electrodes can increase the output power of electrostatic/electret vibration energy harvesters by two orders of magnitude, it is necessary to investigate the dynamic response of molecular orientation and dielectric properties in vibrational flow in the presence of an external field. In order to simultaneously evaluate the orientation and dielectric properties of liquid crystals, a high-aspect-ratio and bridge-structure channel silicon microfluidic device capable of applying a strong magnetic field was fabricated. We used 5CB as a nematic liquid crystal and measured its impedance when subjected to steady and oscillatory laminar flow to clarify its dielectric properties.

Free Research Field

電子デバイス

Academic Significance and Societal Importance of the Research Achievements

環境発電は，周囲の環境に薄く広く存在するエネルギーを回収して小電力電子デバイスを動作させる技術であり，Society 5.0の共通基盤技術としてIoTの社会実装に向けたメンテナンスフリーの自立電源として大きな期待が寄せられている．
小型振動発電の高出力化に寄与する本研究により、電池交換不要な無線センサノードの実現が促進され、構造ヘルスモニタリング，セキュリティ，ウエアラブルデバイスなどへの応用によるサステナブルな社会の実現に貢献できると考える。