3D printing becomes 4D as objects morph over time and temperatures change.
Rutgers engineers have invented a “4D printing” method for a smart gel that could lead to the development of “living” structures in human organs and tissues, soft robots and targeted drug delivery.
The 4D printing approach involves printing a 3D object with a hydrogel (water-containing gel) that changes shape over time when temperatures change, said Howon Lee, senior author of a new study and assistant professor in the Department of Mechanical and Aerospace Engineering at Rutgers University–New Brunswick.
The study, published recently online in Scientific Reports, demonstrates fast, scalable, high-resolution 3D printing of hydrogels, which remain solid and retain their shape despite containing water. Hydrogels are everywhere in our lives, including in Jell-O, contact lenses, diapers and the human body.
The smart gel could provide structural rigidity in organs such as the lungs, and can contain small molecules like water or drugs to be transported in the body and released. It could also create a new area of soft robotics and enable new applications in flexible sensors and actuators, biomedical devices and platforms or scaffolds for cells to grow, Lee said.
“The full potential of this smart hydrogel has not been unleashed until now,” said Lee, who works in the School of Engineering. “We added another dimension to it, and this is the first time anybody has done it on this scale. They’re flexible, shape-morphing materials. I like to call them smart materials.”