Propagation and interactions of hydraulic fractures in model heterogeneous solids

The propagation of cracks in heterogeneous environments is a very rich and complex scientific problem, with implications in many fields, from geology, to everyday life and industrially-relevant processes. Interactions of the propagating crack with material heterogeneities, defects, interfaces and other cracks ultimately determine the path that the crack follows, as well as the occurrence of crack branching and merging.
Addressing such interactions in experiments is however extremely challenging, since it requires at the same time a fine control of the crack propagation and a detailed knowledge of the material response to the crack itself, which is typically nonlinear and dynamic.
In this work we study the propagation of hydraulic fractures in model, well-controlled colloidal materials, using microfluidics coupled to an innovative dynamic light scattering technique providing time- and space-resolved information on the local strain and the microstructural damage caused in the material by the propagating crack. Our preliminary results suggest that combining such information with a fine control of the mechanical and structural properties of our model samples can pave the way for a more comprehensive understanding of crack propagation in heterogeneous media.