Imperial College London
Portrait Picture

DrValeriaGarbin

Faculty of Engineering, Department of Chemical Engineering

Visiting Professor
 
 
 
//

Contact

 

v.garbin

 
 
//

Assistant

 

Ms Sevgi Thompson +44 (0)20 7594 1478

 
//

Location

 

ACE ExtensionSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Jamburidze:2017:10.1039/C6SM02810A,
author = {Jamburidze, A and De, Corato M and Huerre, A and Pommella, A and Garbin, V},
doi = {10.1039/C6SM02810A},
journal = {Soft Matter},
pages = {3946--3953},
title = {High-frequency linear rheology of hydrogels probed by ultrasound-driven microbubble dynamics},
url = {http://dx.doi.org/10.1039/C6SM02810A},
volume = {13},
year = {2017}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Ultrasound-driven microbubble dynamics are central to biomedical applications, from diagnostic imaging to drug delivery and therapy. In therapeutic applications, the bubbles are typically embedded in tissue, and their dynamics are strongly affected by the viscoelastic properties of the soft solid medium. While the behaviour of bubbles in Newtonian fluids is well characterised, a fundamental understanding of the effect on ultrasound-driven bubble dynamics of a soft viscoelastic medium is still being developed. We characterised the resonant behaviour in ultrasound of isolated microbubbles embedded in agarose gels, commonly used as tissue-mimicking phantoms. Gels with different viscoelastic properties were obtained by tuning agarose concentration, and were characterised by standard rheological tests. Isolated bubbles (100–200 μm) were excited by ultrasound (10–50 kHz) at small pressure amplitudes (<1 kPa), to ensure that the deformation of the material and the bubble dynamics remained in the linear regime. The radial dynamics of the bubbles were recorded by high-speed video microscopy. Resonance curves were measured experimentally and fitted to a model combining the Rayleigh–Plesset equation governing bubble dynamics, with the Kelvin–Voigt model for the viscoelastic medium. The resonance frequency of the bubbles was found to increase with increasing shear modulus of the medium, with implications for optimisation of imaging and therapeutic ultrasound protocols. In addition, the viscoelastic properties inferred from ultrasound-driven bubble dynamics differ significantly from those measured at low frequency with the rheometer. Hence, rheological characterisation of biomaterials for medical ultrasound applications requires particular attention to the strain rate applied.
AU  - Jamburidze,A
AU  - De,Corato M
AU  - Huerre,A
AU  - Pommella,A
AU  - Garbin,V
DO  - 10.1039/C6SM02810A
EP  - 3953
PY  - 2017///
SN  - 1744-6848
SP  - 3946
TI  - High-frequency linear rheology of hydrogels probed by ultrasound-driven microbubble dynamics
T2  - Soft Matter
UR  - http://dx.doi.org/10.1039/C6SM02810A
UR  - http://hdl.handle.net/10044/1/48409
VL  - 13
ER  -
Download