Materials Research Science and Engineering Centers for Northwestern University

The Driscoll lab will study the failure of materials with soft interactions, using self-assembled colloidal solids as a starting point. Colloidal particles with long-range interactions can assemble into both liquids and crystalline or glassy solids, and this assembly can be well-controlled by adjusting particle volume fraction and polydispersity. We will create these 2D elastic solids, and then subject them to cyclic loading. Using florescence microscopy, we will image the solid throughout the loading process. This will allow us to extract from the images the dynamics of defect creation, rearrangement, and flow in the crystalline lattice throughout the loading process. We will explore (i) how the lattice accommodates applied stress and (ii) what are the conditions which lead to a steady-state. Our aim is to understand how the material can learn to accommodate applied stress; i.e., the lattice experiences the same cyclic loading, but does not accumulate additional damage.