Mar 14, 2019 | By Thomas

Although 3D printing is being used for a variety of applications in healthcare, biomedical engineering and manufacturing, it is still pretty limited, partly because most 3D printing techniques can only make parts made of one material at a time. Now scientists at the University of Wisconsin-Madison have developed a novel 3D printer that uses patterns of visible and ultraviolet light to 3D print with more than one material.

Currently most multi material 3D printing methods use separate reservoirs of materials to get different materials in the right positions. Researchers found that a one-vat, multiple-component approach, which is similar to a chemist's one-pot approach when synthesizing molecules would be more practical than multiple reservoirs with different materials.

This approach is based on the ability of different wavelengths of light to control which starting materials polymerize into different sections of the solid product. Those starting materials start as simple chemicals, known as monomers, that polymerize together into a longer string of chemicals, like how plastic is made. Depending on which light is used, the final product will have different properties, like stiffness.

The researchers simultaneously direct light from two projectors toward a vat of liquid starting materials, where layers are built one-by-one on a platform. After one layer is built, the build platform moves up, and light helps build the next layer.

The top images show the digital design and its printed form. Purple corresponds to ultraviolet cured stiff epoxide regions, whereas the gray regions are visible light cured acrylate regions that are soft and compliant. At the bottom, the logo for the 3D printing group, MASC, is turned into a printed object composed of both stiff, opaque regions and soft, transparent regions. IMAGE COURTESY A.J. BOYDSTON AND JOHANNA SCHWARTZ

The major hurdle researchers faced was optimizing the chemistry of the starting materials. They first considered how the two monomers would behave together in one vat. They also had to ensure that the monomers had similar curing times so that the hard and soft materials within each layer finished drying at approximately the same time.

With the right chemistry in place, researchers could now dictate exactly where each monomer cured within the printed object by using ultraviolet or visible light.

"At this stage, we've only accomplished putting hard materials next to soft materials in one step," says UW-Madison Professor of Chemistry A.J. Boydston, who led the recent work with his graduate student Johanna Schwartz. "There are many imperfections, but these are exciting new challenges."

Now, Boydston wants to address these imperfections and answer open questions, such as what other monomer combinations can be used and whether different wavelengths of light can be used to cure these new materials. Boydston also hopes to assemble an interdisciplinary team that can increase the impact of wavelength-controlled, multi-material 3D printing.

Using chemical methods to eliminate an engineering bottleneck is exactly what the 3D printing industry needs to move forward, says Schwartz.

"It is this interface of chemistry and engineering that will propel the field to new heights," Schwartz says.

The work was published Feb. 15 in the journal Nature Communications.



Posted in 3D Printing Application



Maybe you also like:


Leave a comment:

Your Name:


Subscribe us to Feeds twitter facebook   

About provides the latest news about 3D printing technology and 3D printers. We are now seven years old and have around 1.5 million unique visitors per month.

News Archive