University of Arkansas undergraduate 3D-prints binderless LEGO-like lunar bricks

Engineers are finding ways to build on the Moon without hauling binders from Earth, and Cole McCallum, a University of Arkansas undergraduate, worked with mechanical engineer Wan Shou to print LEGO-style bricks from simulated lunar regolith using laser powder bed fusion with no binding agent; the team reported the work Nov. 10, 2026.

The team used laser powder bed fusion, a process in which a laser fuses microscopic particles of fine powder into a solid block. They printed two shapes, one resembling a cross and another like the letter H, each a few centimeters wide, designed to connect like LEGOs into larger structures.

Because they had no access to actual lunar material, McCallum and Shou used Lunar Highlands Regolith Simulant (LHS-1), a commercial product that replicates the moon dust that Apollo astronauts gathered during the 1960s and 1970s. Moon dust has no organic matter and consists of loose, jagged particles created by impacts over billions of years, so it cannot bind on its own and needs secondary ingredients.

The laser fuses regolith particles directly to one another, so the powder binds to itself with nothing else involved. “There’s nothing else it’s binding to. The regolith powder is binding to itself,” McCallum said.

Bricks made from pure regolith are more porous and less strong than bricks made with binders. McCallum said he hesitated to call the process ready for supporting other loads right now, though the structures can support themselves. “But I would be hesitant to say our process could be used for something that’s supporting other loads at this moment yet,” he said.

Wan Shou, an assistant professor of mechanical engineering at the University of Arkansas, said researchers still need to learn how the process handles microgravity and vacuum conditions and to improve the bricks’ mechanical performance for practical use. He remains optimistic that the method can efficiently build components and structures for a permanent lunar settlement.

McCallum grew up in Little Rock and completed his degrees in mechanical engineering and physics in May; he received the inaugural Lafayette Fellowship, which chose 30 fellows from more than 3,400 applicants. He joined Shou’s lab early in his undergraduate studies and has since shifted his research focus. “It helps you refine and overcome all the problems you have as a researcher,” McCallum said.

The group’s paper appeared in npj Advanced Manufacturing in 2026 under DOI 10.1038/s44334-026-00111-x. It described using additive manufacturing to convert lunar regolith into reconfigurable habitation blocks.

The point of ditching the binder is in-situ resource utilization, or ISRU: using local lunar resources to build structures, since launching all the needed equipment and materials from Earth is impractical because heavy payloads are expensive. Universe Today reported June 27, 2025, that launch costs have fallen sharply over the last decade thanks to reusable rockets, but sending all the gear needed for a lunar facility remains prohibitively expensive.

The Arkansas team envisioned light-based sintering as a way to make lunar bricks without printing whole structures, a setup needing only lunar material for the structures and ending binder resupply missions from Earth. The team decided the best use case was to make many interlocking, reconfigurable bricks, because the gear fits within lunar mission volume limits and each unit needs only a little fabrication space. The team included researchers from the University of Houston and Tampere University, with McCallum as first author on the paper.

Many lunar construction printing methods call for supplies shipped from Earth – solvents, polymers, or bonding agents – and those bring cost, waste, and energy problems. Shou said solvents cost a lot to ship and can evaporate to cause issues, while binders and polymers create shipping, waste, and energy problems.

A binder-dependent comparison comes from the University of Central Florida, where researchers led by Associate Professor Ranajay Ghosh used binder jet printing on a mix of lunar regolith and saltwater, targeting possible use in NASA’s Artemis base camp; the ScienceDaily release describing it dates to October 25, 2022. After printing weak green parts, the team baked them at high temperatures, and bricks exposed to heat of up to 1200 degrees Celsius withstood pressure of as much as 250 million times Earth’s atmosphere.

Ghosh said binder jet technology is uniquely suitable for ceramic-like materials that are difficult to melt with a laser. “BJT is uniquely suitable for ceramic-like materials that are difficult to melt with a laser,” he said. The study came out in Ceramics International in 2022 under DOI 10.1016/j.ceramint.2022.07.329. NASA’s Artemis base camp concept covers a modern lunar cabin, a rover, and a mobile home.

Universe Today reported June 27, 2025, that NASA’s goal was to land the first woman and the first person of color on the Moon by 2028 on Artemis III, which would mark the first human lunar visit since Apollo crews last stepped onto the Moon in 1972. NASA’s Artemis program aims to enable sustained lunar exploration and development with possible long-term bases and living quarters on the Moon.

NASA and other agencies are eyeing the Moon’s South Pole-Aitken Basin for bases. There, sunlight brings temperatures of 54 degrees Celsius (130 degrees Fahrenheit), while shadow drops them to minus 246 degrees Celsius (minus 410 degrees Fahrenheit), and lunar gravity is 16.5 percent that of Earth. Before full implementation, engineers still must figure out how a printer travels across the lunar surface, where to get power, how vacuum affects sintering, and how to track sunlight with build platforms. “When it comes to full implementation, there’s a lot of engineering that still needs to be done,” McCallum said.

The agency worked with firm SINTERHAB on fitting the ATHLETE rover with microwave-sintering technology for a 3D-printed lunar habitat. Phys.org described the Arkansas work as the first demonstration of sintering lunar regolith simulant directly without a binder into reconfigurable building blocks.