High-speed ultrasound imaging of bubbly flows and shear waves in soft matter

Rosselló, Juan Manuel (author), Ghasemian, Saber Izak (author), Ohl, Claus-Dieter (author)

In this methods paper, we explore the capabilities of high-speed ultrasound imaging (USI) to study fast varying and complex multi-phase structures in liquids and soft materials. Specifically, we assess the advantages and the limitations of this imaging technique through three distinct experiments involving rapid dynamics: the underwater flow induced by an external jet, the dissolution of sub-micron bubbles in water, and the propagation of shear waves in a soft elastic material. The phenomena were simultaneously characterized using optical microscopy and USI. In water, we use compounded USI for tracking a multi-phase flow produced by a jetting bubble diving into a liquid pool at speeds around 20 m s−1. These types of jets are produced by focusing a single laser pulse below the liquid surface. Upon breakup, they create a bubbly flow that exhibits high reflectivity to the ultrasound signal, enabling the visualization of the subsequent turbulent flow. In a second experiment, we demonstrate the potential of USI for recording the diffusive shrinkage of micro- and nanobubbles in water that could not be optically resolved. Puncturing an elastic material with a liquid jet creates shear waves that can be utilized for elastography measurements. We analysed the shape and speed of shear waves produced by different types of jetting bubbles in industrial gelatin. The wave characteristics were simultaneously determined by implementing particle velocimetry in optical and ultrasound measurements. For the latter, we employed a novel method to create homogeneously distributed micro- and nanobubbles in gelatin by illuminating it with a collimated laser beam.

• Language: English
• Keywords: ultrasound imaging, bubble jetting, soft matter, shear waves
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 823–836
• Numbering: Vol. 20, iss. 4
• PID: 20.500.12556/RUL-154227-05d2ac58-f670-96a8-ad20-f810a792c71a
• UDC: 532
• ISSN on article: 1744-6848
• DOI: 10.1039/D3SM01546G
• COBISS.SI-ID: 183563779
• Publication date in RUL: 02.02.2024

Record is a part of a journal

• Title: Soft matter
• Shortened title: Soft matter
• Publisher: Royal Society of Chemistry
• ISSN: 1744-6848
• COBISS.SI-ID: 23741223

Licences

• License: CC BY 3.0, Creative Commons Attribution 3.0 Unported
• Link: https://creativecommons.org/licenses/by/3.0/deed.en
• Description: You are free to reproduce and redistribute the material in any medium or format. You are free to remix, transform, and build upon the material for any purpose, even commercially. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Secondary language

• Language: Slovenian
• Keywords: ultrazvočno slikanje, brizganje mehurčkov, mehka snov, strižni valovi