Shape-shifting 3D printing nozzle reportedly improves composite parts

The morphing nozzle is designed to 3D-print parts made from fiber-filled composites. The nozzle re-orients fibers during printing to enhance part strength or other desired characteristic. University of Maryland

Engineers at the University of Maryland (UMD) have developed a new shape-changing 3D printing nozzle for parts made from fiber-filled composites. The research team says the nozzle’s ability to “morph” during operation can enhance part properties like strength or electrical conductivity.

According to a report from the university’s engineering school, one challenge of working with fiber-filled composites is that their performance is based on orientation of the short fibers, and orientation is difficult to control during the 3D printing process.

“When 3D printing with the morphing nozzle … the side actuators can be inflated like a balloon to change the shape of the nozzle, and in turn, the orientations of the fibers,” said Ryan Sochol, an assistant professor in mechanical engineering and director of the Bioinspired Advanced Manufacturing Laboratory at UMD’s A. James Clark School of Engineering.

Emerging 4D printing applications partially guided the researchers’ work. “4D printing refers to the relatively new concept of 3D printing objects that can reshape or transform, depending on their environment,” said UMD mechanical engineering professor David Bigio. “In our work, we looked at how printed parts swelled when submerged in water, and, specifically, if we could alter that swelling behavior using our morphing nozzle.”

UMD’s Terrapin Works 3D Printing Hub built the morphing nozzle with a Stratasys PolyJet multimaterial printer. Flexible materials were used for the inflatable side actuators and the shape-changing central channel, while the outer casing access port was printed from rigid materials.

The team is exploring using the nozzle for biomedical applications in which bulk printed objects could reshape in the presence of particular stimuli from the body. The team is also in discussions with several Department of Defense laboratories to use the morphing nozzle to support the production of weapons for defense and other military systems.