Printing a Superior Superconductor

Superconductor materials have made a great difference in lives, from powering medical imaging for MRIs to allowing trains to float above tracks as they move, saving energy. 

David Dunand

Yet there also has been a frustrating downside to more advanced superconductors: their ceramic property makes them brittle. 

“Ceramic-based cuprates are common high-temperature superconductors, and, because they operate with liquid nitrogen, are immensely cheaper and easier to work with than low temperature metal superconductors,” said David Dunand, professor of materials science and engineering at the McCormick School of Engineering. “The shapes these materials can make, however, have been limited because of their brittleness. You’d like to be able to make complex objects that are optimized for energy efficiency.”

Dunand and collaborators from Fermilab are out to change this with the help of 3D printing, Their printing method printed superconductors that will have more power, which will help superconductor-powered inventions cost less.

The team’s work is outlined in the paper “Additively-manufactured Monocrystalline YBCO Superconductor,” published Feb. 24 in Nature Communications. Dunand was a co-corresponding author of the paper along with Dingchang Zhang (PhD ’24), a postdoctoral researcher at the University California, Berkeley, and a former student in Dunand’s lab. Cristian Boffo, PIP-II project manager at Fermilab, also co-authored the study.

This is an image of the 3D printing of superconducting material.

A breakthrough for a breakthrough

To not be limited by the brittleness of cuprates, the research team developed a method to successfully produce single-crystal YBCO — a common polycrystal superconductor —using additive manufacturing, commonly known as 3D printing.

Breaking down the process, the first step uses commercially available precursor powder to prepare ink. Ink is then put in a syringe that is extruded to create YBCO micro-lattices or other complex geometries that are polycrystals. The 3D-printed material later becomes a single crystal on 3D-printed parts by a melt growth method.

Normally, bulk superconductors are created in simple form by mold pressing. They are then sintered, or heated, and the pressed powders merge together. The researchers here used an ink where the powder is suspended and applied 3D printing to make it into a complex object for sintering.  

The researchers were also able to remove the material’s grain boundaries — small defects in crystal structures that can lessen a material’s electrical and thermal conductivity. This presented a more effective superconducting current.

“People have made single crystals in a block of material, and we’ve shown we can use this same technique with 3D printing,” Zhang said. “During our process, we can fabricate complex shapes, such as toroidal coils, with a single crystal seed placed on top. Through a controlled processing window, these 3D-printed parts partially melt and transform into single crystals, retaining their original 3D-printed shape.”

“At Fermilab, we are developing the next-generation superconducting magnets that will drive scientific experiments for decades to come,” Boffo said. “The technology created through this collaboration will enable designs that were previously unimaginable, thereby enhancing our potential for advancement.”

"The single-crystal object can carry a greater amount of electrical current, making it able to provide more power, thus making magnets immensely stronger,” Dunand said. “This provides more energy for particle accelerators, such as FermiLab. The faster particles may in fact unlock new discoveries for physicists.”

Super possibilities

According to Dunand, this work has the potential to only be the beginning of more powerful and efficient superconductors. The group plans to apply their method to other ceramic superconductor materials.

“We did this research with YBCO, the most common superconductor, but there are many other compounds with even higher performance temperatures than can be processed by our method,” Dunand said. “The possible applications for this are very exciting.”