On October 24, 2025, scientists at the Swiss Federal Institute of Technology Lausanne (EPFL) developed a groundbreaking three-dimensional printing method that uses hydrogels as templates to significantly enhance the density and strength of metals and ceramics. The team stated that this new technology can produce materials up to 20 times stronger than their counterparts made using traditional methods, while substantially reducing the risk of deformation during the forming process.
According to reports, the new process initially uses hydrogels to print a three-dimensional structural framework, which is then immersed in a metal salt solution. Through chemical conversion, metal nanoparticles are generated throughout the gel. The metal content is further increased through multiple rounds of metal salt infusion and conversion. Finally, the remaining hydrogel is removed by heating, leaving behind a structurally intact and highly dense metal or ceramic entity. It is worth noting that this "print-then-infuse" approach allows the hydrogel model to be flexibly transformed into various metals, ceramics, or composite materials.
Daryl Yee, head of the Laboratory for Materials Chemistry and Manufacturing, who leads the project, explained that traditional photopolymerization printing techniques are limited to processing photosensitive polymers, restricting material types and making it difficult to achieve high-strength parts. Previous attempts to convert printed polymers into metals or ceramics often resulted in voids that compromised material strength and significant shrinkage leading to deformation. The hydrogel printing method effectively overcomes these challenges and significantly improves the density and mechanical properties of the final products.
In the latest study, the team used this technology to fabricate complex mathematical lattice structures (such as "gyroids") from metals including iron, silver, and copper. Mechanical testing instruments demonstrated that their load-bearing capacity is 20 times higher than that of conventional methods, while the shrinkage rate of the final product is only 20% (significantly lower than the 60%–90% shrinkage rate of traditional processes). In addition to combining strength and lightweight properties, this method is particularly suitable for applications with specific requirements for structural complexity and high strength, such as sensors, biomedical devices, and energy converters. Future application prospects also include high-surface-area metals for catalytic reactions and high-efficiency cooling structures.
The research team revealed that subsequent efforts will focus on industrial-scale upgrades, improving material density, and accelerating the production process. Although the current multi-step infusion process enhances performance, it is time-consuming. Researchers are now exploring robotic automation to speed up the overall processing.
