Azo Materials caught wind of a brand-new article published in the journal Science Advances. This article, written by researchers from Singapore University of Technology and Design (SUTD) and Georgia Institute of Technology, details the development of a new 4D printing process.
4D printing is “the process of integration of 3D printing and active material technologies in order to create structures [capable of changing] conformations/shapes with an environmental stimulus such as heat or moisture.”
“Active polymers, such as hydrogels and shape memory polymers (SMPs), are two of the most widely used active polymers in 4D printing. In the hydrogel-based 4D prints, a non-swelling polymer is integrated with the hydrogel. The hydrogel swells when the 4D print is immersed in a solvent, creating mismatch strains between the hydrogel and the non-swelling polymer that causes an overall change in the shape of the 4D structure.”
In order to simplify the often slow and complicated process involved in 4D printing with SMPs, the teams at SUTD and Georgia Institute of Technology “used a composite consisting of a glassy shape memory polymer and an elastomer, that is programmed with a built-in compressive strain. They then integrated the programming steps into the 3D printing process by controlling the photopolymerization step during printing.”
As a result, the teams’ “4D structures have complex geometric forms at a high spatial resolution, while also exhibiting a high-fidelity feature with controlled built-in strains…this new permanent shape can also be reprogrammed into multiple subsequent shapes.”
“To demonstrate their new process, the team created several models, including a flower [capable of opening] its petals upon heating and a lattice model [capable of expanding] up to eight times its original size after heating.”
This all sounds fascinating, of course, but what about practical implications?
Well, the teams believe this new 4D printing process “can improve printing time and material savings up to 90 percent, while also eliminating the hassle of mechanical programming from the design and manufacturing work flow… [This process also] has promising applications in the [medical, aerospace, and consumer products industries.]”
Image and Quotes Courtesy of Azo Materials