Imagine printing out molecules that can respond to their surroundings. A research project at the University of Washington merges custom chemistry and 3-D printing. Scientists created a bone-shaped plastic tab that turns purple under stretching, offering an easy way to record the force on an object.
“At the UW, this is a marriage that’s been waiting to happen – 3-D printing from the engineering side, and functional materials from the chemistry side,” said Andrew J. Boydston, a UW assistant professor of chemistry. He is corresponding author on a recent paper in the American Chemical Society’s journal of Applied Materials and Interfaces (“3D-Printed Mechanochromic Materials”).
Gregory Peterson and Michael Larsen, UW doctoral students in chemistry, created a polymer, or plastic made up of many repeated units strung together, and fed the soft plastic into the UW chemistry lab’s commercial 3-D printer.
One print head contained polycaprolactone, similar to what a 3-D printer company sells as Flexible Filament. The other print head contained a plastic that is 99.5 percent identical but the UW team made occasional insertions of a molecule, spiropyran, that changes color when it is stretched. … (read more)