Discovery by researchers at Queen's University (Kingston, ON, Canada) about how molecules in glass or plastic are able to move when exposed to laser light could facilitate the distribution of medicine by allowing doctors to control the time and rate at which drugs in a plastic carrier could be released through the body.
"Glasses and plastics are mysterious materials. We knew how the molecules moved in a liquid, but we didn't know how they moved in a glass or plastic-no one did," said lead researcher Jean-Michel Nunzi, adding that "molecular cooperation" turns out to be the key. He compares the motion to cars in a crowded parking garage: If the garage is full, then one car cannot move unless another also moves. In the case of molecules in plastic, light triggers slight movement in those illuminated by the laser-but only cooperation with other molecules enables significant shifts. Molecules not exposed to the light remain stable. The result is a dramatic change, visible to the naked eye, in the shape of the material.
The findings were published in the Journal of Chemical Physics.