‘4D’ printed objects can change over time in response to new demands

3D printing promises to give us objects on demand. But 4D printing promises to give us objects that change over time, adapting to new situations and needs.

An $855,000 grant from the United States Army Research Office is enabling researchers from three universities to develop materials capable of changing after they are 3D printed. For example, an outfit printed for a soldier could change to a camouflage print or adjust to be resistant to shrapnel.

“If you use materials that possess the ability to change their properties or shape multiple times, you don’t have to build for a specific, one-time use,” co-principal investigator Jennifer Lewis said in a release. “Composites that can be reconfigured in the presence of different stimuli could dramatically extend the reach of 3D printing.”

The researchers will build the new type of objects by printing one material within another. Both materials will be capable of responding to surrounding characteristics like temperature or touch.

“The ability to create one fabric that responds to light by changing its color and to temperature by altering its permeability, and even to an external force by hardening its structure, becomes possible through the creation of responsive materials that are simultaneously adaptive, flexible, lightweight and strong,” co-principal investigator Ralph Nuzzo said in the release. “It’s this complicated functionality that makes true 4D printing a game changer.”