Soft, solid or hard?
Weizmann Institute scientists developed new theoretical approaches that explain the physical processes causing soft-solid materials to behave like solids. Soft-solid materials, such as rubber, biological substances, gels, emulsions, microemulsions and colloids, play an important role in the food and drug industries. The Institute's scientists indicated the characteristics of soft-solid substances and that their hardness differs from that of regular solids.
Thin membranes caught in suspended animation
Physicists from the Weizmann Institute of Science gained a new understanding of the rules of behavior of thin membranes such as those enveloping living cells. This knowledge has been applied to the dynamic and nonlinear processes in artificial membranes, and may help to clarify the activity of living cell membranes.
Cell membranes permit the selective passage of substances and bodies into and out of cells, and play a central role in the cell's life processes, including division, binding with other cells or surfaces, differentiation, and death.
In their studies, the researchers simulated phenomena occurring in living cells, such as flow, formation of chains of cell components, and emission of bubbles through the membrane. The membranes are in constant development and motion; to "fix them" for scientific observation, the scientists used concentrated laser beams. The laser photons trap the membrane, fix it in place and even permit control over its surface tension.