Scientists Grow Metal Instead of 3D Printing It — And It’s 20x Stronger
LAUSANNE, Switzerland – Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) have pioneered a revolutionary 3D printing technique that "grows" high-performance metals and ceramics, resulting in final products that are dramatically stronger and more dimensionally stable than those made with existing methods.
The new process, developed in the Laboratory for the Chemistry of Materials and Manufacturing, fundamentally rethinks how additive manufacturing works with tough materials. Instead of printing with a resin pre-mixed with metal powders—a method that often leads to porous and brittle results—the team first 3D prints a template from a simple, water-based hydrogel.
This hydrogel scaffold is then repeatedly infused with metal salts. During each infusion cycle, the salts chemically transform into nanoparticles that fill the gel's structure. After 5 to 10 cycles, the gel is removed by heat, leaving behind a dense, pure metal or ceramic object that retains the intricate shape of the original print.
"This approach addresses major flaws in existing methods," said Dr. Daryl Yee, the lab's head. "These materials tend to be porous, which significantly reduces their strength, and the parts suffer from excessive shrinkage, which causes warping."
The results are striking. Tests on intricate gyroid structures made from iron, silver, and copper showed that the new technique produces materials that can withstand 20 times more pressure than those from previous polymer-to-metal 3D printing techniques. Furthermore, shrinkage was drastically reduced to just 20%, compared to 60-90% with conventional methods.
"Our work not only enables the fabrication of high-quality metals and ceramics with an accessible, low-cost 3D printing process; it also highlights a new paradigm in additive manufacturing where material selection occurs after 3D printing, rather than before," Yee summarized.
This breakthrough is particularly promising for applications that demand complex, strong, and lightweight 3D architectures, such as next-generation sensors, biomedical implants, and components for energy conversion and storage.
The team is now focused on industrial translation, working to further increase material density and automate the infusion process with robotics to reduce the total manufacturing time.