US researchers develop smart gel for 4D printing

1 February 2018 (Last Updated February 1st, 2018 11:14)

Engineers at Rutgers University-New Brunswick in the US have 3D-printed a high-resolution smart gel that can become 4D over time by changing its shape based on changes in temperatures.

US researchers develop smart gel for 4D printing
A tiny chess king, 3D-printed with a temperature-responsive hydrogel. Credit: Daehoon Han / Rutgers University-New Brunswick.

Engineers at Rutgers University-New Brunswick in the US have 3D-printed a high-resolution smart gel that can become 4D over time by changing its shape based on changes in temperatures.

The water-containing gel (hydrogel) is believed to possess the potential to aid in the development of living structures in human organs and tissues, soft robots, and targeted drug delivery.

The ability of this gel to remain solid even while containing water is expected to provide structural rigidity to organs. It could also hold small molecules such as water or drugs to be carried and released inside the body.

The gel is also said to allow the development of a new soft robotics area, as well as facilitate new applications in flexible sensors and actuators, biomedical devices and platforms or scaffolds for cell growth.

Rutgers University Mechanical and Aerospace Engineering department assistant professor Howon Lee said: “The full potential of this smart hydrogel has not been unleashed until now.

“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.”

“We added another dimension to it, and this is the first time anybody has done it on this scale.”

During the study, a fast and inexpensive lithography-based technique was used to print layers of a special resin into a 3D shape.

This resin included the hydrogel, a chemical to act as a binder, another chemical to enable bonding when exposed to light, and a dye for controlling penetration of the light.

The researchers observed the way hydrogel’s growth and shrinkage varied with different temperatures and learned to accurately control it.

Lee added: “If you have full control of the shape, then you can programme its function. I think that’s the power of 3D printing of shape-shifting material.”