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Event

【GIR Open Seminar】 Dr. James Friend / Washington University in St. Louis (U.S.A.)

Date 2026.9.28 (16：30 - 18：00)
Venue

South Seminar Room 501, 5th Fl., Building 6, Koganei Campus, TUAT
Speaker Dr. James Friend

Affiliation Washington University in St. Louis (U.S.A.)
Title "Making the Invisible Measurable: Interfacial Fluid Dynamics from Nanometer Confinement to Capillary-Wave Turbulence"

＜Abstract＞
High-speed digital holographic microscopy reconstructs the complete, rapidly evolving geometry of a fluid interface with nanometer-scale out-of-plane sensitivity. Applied to a 40 µL droplet excited by 7 MHz ultrasound, the method reveals how much slower capillary waves emerge through nonlinear feedback among acoustic radiation pressure, the evolving interface, and the acoustic field within the droplet. As excitation increases, the surface progresses through discrete, intermediate, kinetic, and strongly nonlinear wave-turbulence regimes before atomization. These observations challenge conventional Faraday-wave interpretations and show why strong interfacial turbulence must be understood to predict ultrasonic spray formation. The same measurement approach is extended to liquids confined in 7 and 25 nm tall nanoslits, where ordinary optical imaging cannot directly resolve the fluid. Careful phase reconstruction and systematic suppression of optical, structural, drift, and shot noise make it possible to quantify fluid height, evaporation, dewetting, and meniscus motion within these structures.

Across these studies, fluid interfaces emerge not as passive boundaries, but as active elements that reshape acoustic fields, redistribute energy, and govern behavior across scales. The scientific and professional portions of the seminar share a broader message: progress often begins by recognizing uncertainty, developing a way to make it measurable, and communicating the result well enough that others can build upon it.
Language English
Intended for everyone is welcome to join
Organized by Institute of Global Innovation Research, ARC-Kawano Team
Contact Institute of Global Innovation Research / Institute of Engineering
Associate Professor Yuta Kurashina
e-mail: kurashina (at) go.tuat.ac.jp
Remarks

This seminar will only be held face-to-face.

 

Biography
James Friend is the Stephen F. and Camilla T. Brauer Distinguished Professor of Mechanical Engineering and Chair of Mechanical Engineering and Materials Science at Washington University in St. Louis. His research explores acoustic phenomena at small scales, especially for biomedical applications and emerging technologies. Before joining Washington University, he held faculty positions in Japan, Australia, and at UC San Diego, where he was appointed in engineering and surgery. He has authored more than 350 peer-reviewed publications, holds 30 granted patents, and has secured more than $37 million in competitive research funding. He has founded or co-founded multiple technology companies, including Latchability, GlideNeuro, and Sonocharge Energy, and is a Fellow of IEEE and the Royal Society of Chemistry.

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