Researchers have developed a new 3D printing method that offers intricate constructions for next-generation energy, biomedical, and sensing technologies.
Developed by researchers at EPFL, the new method helps grow metals and ceramics inside a water-based gel, resulting in exceptionally dense constructions.
Researchers revealed that rather than using light to harden a resin pre-infused with metal precursors, as previous methods have done, they first created a 3D scaffold out of a simple water-based gel called a hydrogel.
Low-cost 3D printing process
Then, they infuse this ‘blank’ hydrogel with metal salts, before chemically converting them into metal-containing nanoparticles that permeate the structure. This process can then be repeated to yield very high metal concentration composites.
“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,” said Daryl Yee, head of the Laboratory for the Chemistry of Materials and Manufacturing.
Materials could withstand 20 times more pressure
Yiming Ji, the first author of the study, also underlined that their materials could withstand 20 times more pressure compared to those produced with previous methods, while exhibiting only 20% shrinkage versus 60-90%.
The research team highlighted that they fabricated intricate mathematical lattice shapes called gyroids out of iron, silver, and copper, demonstrating their technique’s ability to produce strong yet complex structures. To test the strength of their materials, they used a device called a universal testing machine to apply increasing pressure to the gyroids, according to a press release.
The method is claimed to be interesting for the fabrication of advanced 3D architectures that must be simultaneously strong, lightweight, and complex, like sensors, biomedical devices, or devices for energy conversion and storage.
Versatile method for fabricating dense architected ceramics
For example, metal catalysts enable reactions that convert chemical energy into electricity. Other applications could include high-surface area metals with advanced cooling properties for energy technologies.
Published in Advanced Materials, the study reveals a versatile method for fabricating dense architected ceramics and metals with low conversion linear shrinkages. Central to this method is a post-fabrication repeated infusion-coprecipitation process that progressively increases the metal loading in the 3D “blank” hydrogels. Thermal treatment of these high-metal-content hydrogels then converts them into ceramic or metal architectures.
“To demonstrate the versatility of this approach, a variety of 3D ceramic and metal structures with shrinkages as low as 20% while maintaining densities >80% are fabricated,” said researchers in the study.
“This infusion-precipitation-based process thus enables the VP of high-quality ceramics and metals, which is necessary for the fabrication of advanced architected materials and devices.”
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