Polymers that change from hard to soft or vice versa when exposed to a liquid

07-Mar-08

Ground-breaking work has been published on a new type of polymer that displays chemoresponsive mechanic adaptability, meaning the polymer can change from hard to soft plastic and vice versa in seconds when exposed to liquid. The paper has been published by an interdisciplinary team of researchers from the departments of macromolecular science and engineering and biomedical engineering at the Case School of Engineering and the Louis Stokes Cleveland Department of Veterans Affairs Medical Center. A radically new approach for developing polymer nanocomposites which alter their mechanical properties when exposed to certain chemical stimuli has been discovered. These new polymers can be engineered to change their mechanical properties, in particular stiffness and strength, in a programmed fashion when exposed to a specific chemical. The materials reported were designed to change from a hard plastic to a soft rubber when brought in contact with water. The new materials were tailored to respond specifically to water and to exhibit minimal swelling, so they don't soak up water like a sponge. In their new approach, the team used a biomimetic approach -- or mimicking biology -- copying nature's design found in the skin of sea cucumbers.