Experimental study of concentration Marangoni convection induced by multiphoton absorption concentration modulation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14647
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Shizuoka University
• Principal Investigator: Mizushima Yuki 静岡大学, 工学部, 助教 (30844716)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 濃度差マランゴニ対流 / フェムト秒パルスレーザー / レーザー誘起プラズマ / 光ファイバープローブ

Outline of Final Research Achievements

We have developed the principle of a method for non-thermal control of fluid interfaces (MCM, Multiphoton absorption Concentration Modulation) via femtosecond laser pulses (fs pulses) and a method (LMDP, LMDP, Liquid-surface Molecular Densitometry Probing) for estimating interfacial molecular concentrations via an optical fiber probe.
In the MCM development, we developed a technique to induce concentration Marangoni convection by inactivating surfactants by spatially modulating and focusing fs pulses in arbitrary patterns, which form a local concentration gradient.
In the development of LMDP, we constructed a technique to measure the light intensity that changes according to the local concentration of surfactant using optical fibers. The principle of a new measurement for molecular concentration, microscopic distance, and velocity at the interface was developed.

Free Research Field

流体力学

Academic Significance and Societal Importance of the Research Achievements

濃度差マランゴニ対流は半導体結晶の高純度化や熱交換器の伝熱促進等、幅広い分野で応用が進む一方でその流動を明らかにする実験手法・実験条件は限定的である。
本研究は濃度差マランゴニ対流を光によって制御し、さらにその局所的な流れの様子を計測する手法を新たに確立した。いまだ不明な点の多い濃度差マランゴニ対流を多角的かつ実験的に明らかにする準備が整ったことは工学的に極めて有用であり、応用技術の高精度化や省エネに資する基盤研究として引き続き推進してゆく。