Materials ’remember’ past stresses as they age

A new study by University of Chicago and University of Pennsylvania scientists shows that as materials age, they 'remember' prior stresses and external forces, which researchers can then use to create new materials with unique properties. The study, published Dec. 20 in  Science Advances , found that certain types of materials have a "memory" of how they were processed, stored, and manipulated. Researchers were then able to use this memory to control how a material ages and to encode specific properties that allow it to perform new functions. Study author  Andrea Liu  of the University of Pennsylvania said that the study demonstrates a "totally different" way to think about making new materials. "You start with a disordered system, and if you apply the right stresses you can make it come out with the properties you want," she said.  "The possibilities at this stage seem limitless," said co-author  Sidney R. Nagel , the Stein-Freiler Distinguished Service Professor of Physics at the University of Chicago, whose innovative research studies the physics of moving systems, such as falling drops. Liu and Nagel have worked together for many years on the physics of disordered systems.