Development of non-invasive shear wave elastography to assess the mechanical and fracture behavior of tough model gels*

Assessing biomechanical properties of soft tissues by ultrasound imaging is still a challenge to help physician to characterize pathologies. Benefiting from the recent progress in the field, the idea is to develop a new tool – being non-invasive and high time-resolution – devoted to the understanding of fracture processes in synthetic model gels. This approach gives new insights into soft matter fracture.
This project focuses on the use of shear wave elastography to map a local elasticity at the vicinity of a crack tip. Polymer networks with well-controlled mechanical responses are synthetized following the protocol of Rose [1]. By addition of silica nanoparticles (NPs), gels combine a covalent polymer network (elasticity) with physical interactions by adsorption of polymer onto silica NPs involving time-dependent response (viscoelasticity) [2]. Gels are characterized in a wide range of frequencies in tensile mode (small frequencies) coupled with shear wave elastography (high frequencies) [3].

[1] Rose, Dizeux, Narita, Hourdet, Marcellan. Macromolecules, 2013
[2] Rose, Prevoteau, Elziere, Hourdet, Marcellan, Leibler. Nature, 2014
[3] Deffieux, Montaldo, Tanter, Fink. Trans. Med. Imaging, 2009