Imperial College London

Professor Omar K. Matar

Faculty of EngineeringDepartment of Chemical Engineering

Vice-Dean (Education), Faculty of Engineering
 
 
 
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Contact

 

+44 (0)20 7594 9618o.matar Website

 
 
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Assistant

 

Miss Nazma Mojid +44 (0)20 7594 3918

 
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Location

 

506ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Tinguely:2016:10.1039/C5SM03084F,
author = {Tinguely, M and Hennessy, MG and Pommella, A and Matar, OK and Garbin, V},
doi = {10.1039/C5SM03084F},
journal = {Soft Matter},
pages = {4247--4256},
title = {Surface waves on a soft viscoelastic layer produced by an oscillating microbubble},
url = {http://dx.doi.org/10.1039/C5SM03084F},
volume = {12},
year = {2016}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Ultrasound-driven bubbles can cause significant deformation of soft viscoelastic layers, for instance in surface cleaning and biomedical applications. The effect of the viscoelastic properties of a boundary on the bubble–boundary interaction has been explored only qualitatively, and remains poorly understood. We investigate the dynamic deformation of a viscoelastic layer induced by the volumetric oscillations of an ultrasound-driven microbubble. High-speed video microscopy is used to observe the deformation produced by a bubble oscillating at 17–20 kHz in contact with the surface of a hydrogel. The localised oscillating pressure applied by the bubble generates surface elastic (Rayleigh) waves on the gel, characterised by elliptical particle trajectories. The tilt angle of the elliptical trajectories varies with increasing distance from the bubble. Unexpectedly, the direction of rotation of the surface elements on the elliptical trajectories shifts from prograde to retrograde at a distance from the bubble that depends on the viscoelastic properties of the gel. To explain these behaviours, we develop a simple three-dimensional model for the deformation of a viscoelastic solid by a localised oscillating force. By using as input for the model the values of the shear modulus obtained from the propagation velocity of the Rayleigh waves, we find good qualitative agreement with the experimental observations.
AU - Tinguely,M
AU - Hennessy,MG
AU - Pommella,A
AU - Matar,OK
AU - Garbin,V
DO - 10.1039/C5SM03084F
EP - 4256
PY - 2016///
SN - 1744-6848
SP - 4247
TI - Surface waves on a soft viscoelastic layer produced by an oscillating microbubble
T2 - Soft Matter
UR - http://dx.doi.org/10.1039/C5SM03084F
UR - http://hdl.handle.net/10044/1/30886
VL - 12
ER -