Most 3D printed parts today are fragile and cheap, often used for prototyping of larger devices or for toys.

Researchers at Texas A&M University are looking to make 3D printed parts stronger for real-world applications by using traditional welding concepts that bond the sub-millimeter layers in a 3D printed part together while in a microwave.

3D printed objects are made up of thin layers of materials—often plastics—that are deposited on top of each other to form a desired shape. These layers are prone to fracturing, resulting in durability and reliability issues when used in a real-world application.

"I knew that nearly the entire industry was facing this problem," said Brandon Sweeney, a postdoctoral student at Texas A&M. "Currently, prototype parts can be 3D printed to see if something will fit in a certain design, but they cannot actually be used for a purpose beyond that."

The idea is to integrate carbon nanotubes into 3D printed parts, using microwave energy to weld the layers together. Because 3D printed parts can’t be stuck in an oven due to melting, the researchers looked at welding because it employs a point source of heat, like a torch, to join the surfaces of the parts together. Because the layers making up the 3D printed parts are incredibly small, special materials are used to control where the heat hits and bonds the layers together.

"What we do is take 3D printer filament and put a thin layer of our material, a carbon nanotube composite, on the outside," Sweeney said. "When you print the parts out, that thin layer gets embedded at the interfaces of all the plastic strands. Then we stick it in a microwave, we use a bit more of a sophisticated microwave oven in this research, and monitor the temperature with an infrared camera."

As the part is being printed, the welding process is happening simultaneously. The method is currently in the beta phase but has the potential to be included in every industrial and consumer 3D printer where stronger parts are needed, according to Texas A&M.

The full research report can be found in the journal Science Advances.