Soft Matter Seminar: High-intensity ultrasound and soft matter

Sebastien Manneville, Ecole Normale Supérieure de Lyon

Ultrasound is commonly used in medicine both at low intensity for diagnosis (echography) and at high intensity for therapy (lithotripsy or tumour treatment). The goal of this talk is to show that high-intensity ultrasound may provide key fundamental insights into the mechanics of soft materials and open new research avenues. First, I will recall how high-power ultrasound exerts a force, the so-called acoustic radiation force, on an interface or on a small object embedded in a homogeneous fluid [1]. I will then introduce an experimental setup that probes the rheology of a soft jammed material at a “mesoscale” of a few 100 μm thanks to the acoustic radiation force [2]. Second, I will demonstrate that high-intensity focused ultrasound can unjam and locally fluidize a wet granular packing [3].Third, by directly coupling high-intensity ultrasound to a rheometer and to ultrasmall-angle x-ray scattering, I will quantitatively assess the spectacular effects of ultrasound on the viscoelastic and flow properties of various colloidal gels [4]. 


[1] P. Lidon et al., Measurement of the acoustic radiation force on a sphere embedded in a soft solid, Applied Physics Letters 110, 044103, 2017

[2] P. Lidon et al., A mesoscale study of creep in a microgel using the acoustic radiation force, Soft Matter 15, 2688-2702, 2019

[3] P. Lidon et al., Grains unchained: local fluidization of a granular packing by focused ultrasound, Soft Matter 12, 2315-2322, 2016

[4] T. Gibaud et al., Tuning the mechanical and flow properties of colloidal gels with ultrasound, https://arxiv.org/abs/1905.07282

Thursday, June 13 at 10:00am


Regents Hall, 351
3700 O St. NW

Event Type

Academic Events

Audience

Students, Faculty/Staff

Departments

Georgetown College, Institute for Soft Matter Synthesis and Metrology

Tags

Seminar

Presenter

Sebastien Manneville, Ecole Normale Supérieure de Lyon

Event Contact Name

Prof. Peter Olmsted

Event Contact Email

pdo7@georgetown.edu

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