Images and Movies
Mechanical properties of silk
A crystalline unit of spider silk made from a stack of beta-sheets is subjected to an external force which induces its rupture. In the most simple scenario which we mimicked in the simulation visualized here, one of the strands, here the central beta-strand, is pulled away from the others along the fiber running direction. Remarkably, during pulling, the crystal hardly deforms until it suddently ruptures, the hallmark of a stiff and brittle material.See Senbo Xiao et al in our publication list for more information.
Stress-induced rupture of a circular graphene sheet
The movies show the rupture of a graphene sheet upon indentation by an atomic force microscope tip.
Shown in both cases are a color-coded representation of stress due to indentation. Green represents low levels of background stress due to thermal fluctuations of the graphene atoms; orange represents high stress, delimiting the area in which the bond breaking will very probably take place.
Rupture seen from the side. MPG, 11.3 MB, 768×576 pixel
Rupture seen from the bottom MPG, 13.1 MB, 768×576 pixel