ETH Zurich Students Create Groundbreaking Multi-Metal 3D Printing Technology
In a leap that could transform aerospace manufacturing and beyond, students at ETH Zurich have developed a novel laser powder bed fusion (LPBF) system capable of printing multiple metals simultaneously.
By employing a rotating tool path rather than the conventional linear approach, the machine dramatically reduces production time while opening new horizons for complex cylindrical components.
The project, codenamed RAPTURE, has already attracted significant attention, leading to a patent application and a nomination for the prestigious ETH Spark Award.
Revolutionising aerospace production
Modern aerospace engineering leans heavily on 3D printing to merge structural strength with intricate functionality. The ETH student team has pushed the envelope with a high-speed, multi-material LPBF machine designed to tackle one of aerospace’s toughest challenges: manufacturing complex, heat-resistant components quickly and cost-effectively.
Guided by Professor Markus Bambach and Senior Scientist Michael Tucker, six Bachelor’s students from ETH’s Advanced Manufacturing Lab designed, built, and tested the machine in just nine months. The target application? Rocket nozzles, turbomachinery, and other aerospace parts that benefit from cylindrical geometry.
“For small players like our student rocket team, this sort of multi-material technology has up to now been too complex and too expensive, putting it out of reach,” explains Tucker.
Addressing ARIS’s space-bound ambitions
The concept was born out of a real-world need. ETH’s own ARIS (Academic Space Initiative Switzerland) programme is working on bi-liquid-fuelled rocket nozzles designed to withstand extreme thermal and mechanical stresses during launches that could reach the Kármán Line, 100 kilometres above Earth.
In such components, a copper interior optimises heat conduction and cooling, while a nickel alloy exterior provides the necessary heat resistance. Until now, producing such parts required multiple manufacturing stages, driving up costs and complexity.
Rotational printing for uninterrupted production
The heart of the RAPTURE machine is its rotating platform, which applies powder and fuses it with a laser simultaneously. In conventional LPBF, production halts after each layer to spread a new one. This stop-start process slows throughput dramatically.
The rotating method not only eliminates downtime but also reduces manufacturing time for cylindrical parts by over two-thirds. It’s particularly suited to rocket nozzles, rotating engines, and similar components that combine large diameters with thin walls.
“They typically have a large diameter but very thin walls,” notes Tucker. “The rotating architecture lets us print them far more efficiently.”
Multi-metal capability in a single build
One of the standout features of the ETH machine is its ability to print with two metals simultaneously. Conventional systems often require multiple runs, with significant waste when separating mixed powders proves impractical. The ETH approach applies each material only where needed, slashing waste and material costs.
An integrated inert gas system prevents oxidation during printing. By-products like soot and spatter are extracted in real time, maintaining part quality. Initially underestimated, gas flow control has emerged as a crucial factor in print quality. The rotating build environment allows for far more precise control than conventional designs.
Engineering ingenuity under pressure
Developing this machine posed significant technical challenges. Synchronising the scanning laser with rotating gas and powder delivery systems required custom engineering. Many parts, such as the rotatable gas inlet and automatic powder refill mechanism, had to be designed from scratch.
Despite these hurdles, the team delivered a fully functional prototype that looks almost production-ready. Tucker is quick to highlight the achievement: “The fact that a team of students developed and built a functioning machine in nine months is pretty remarkable.”
Beyond rockets
While aerospace remains the prime target, the RAPTURE system’s applications extend well beyond space technology.
Potential uses include:
- Aviation and gas turbines – for precision, high-performance components
- E-mobility – manufacturing ring-shaped parts for electric motors
- High-performance mechanical engineering – producing custom geometries without prohibitive lead times
With the prototype producing parts up to 20 centimetres in diameter, the next challenge lies in scaling the process for larger parts and faster production speeds. ETH is actively seeking industry partners to refine and commercialise the technology.
A promising future for additive manufacturing
ETH’s patent application signals both confidence and commercial ambition for the rotary multi-material LPBF approach. The Spark Award nomination underscores the innovation’s disruptive potential in the high-stakes arena of advanced manufacturing.
If adopted at scale, this technology could reshape the economics of multi-metal component production, particularly for industries where complex geometries and high-performance materials are non-negotiable.
The student-led project proves that with vision, mentorship, and technical skill, even the most challenging manufacturing problems can be addressed in record time.
