Researchers want to make salt printing marketable

Materials scientists Nicole Kleger and Simona Fehlmann have developed a 3D printing process to create salt patterns that they can fill with other materials. One area of ​​application is the creation of highly porous lightweight metal components. Two Pioneer Fellows are currently trying to move this process into the industry.

Not long ago, materials researcher scored a coup: they used a 3D printer to create a framework out of salt, which they then filled with liquid magnesium. After the light metal cooled and hardened, the researchers filtered out the salt framework, resulting in a highly porous magnesium object that would be suitable, such as a decomposable bone implant. biological.

The original technology has been successfully improved

Now, the lead author of that study, Nicole Kleger, and her former student, Simona Fehlmann, have published another paper in the journal Nature. Advanced Materials. In it, they report that together with an interdisciplinary team, they have refined and modified their process to create more complex salt rigs with even finer pores.

Instead of using an extrusion printer that prints out tiny filaments of the salt mixture in a mesh-like pattern from a tiny nozzle, the researchers led by Kleger and Fehlmann used an embossed device and printing ink based on salt particles.

By mixing the ink with the appropriate monomers, the scientists made it light-sensitive. This means that when exposed to light, the monomers combine to form rigid polymers in the process. This makes it possible to build complex structures layer by layer. The salt framework created in this way then acts as a template, or negative template, which is filled with another material.

In the next step of this novel process, the materials scientists then either fill the prefabricated structures with not only magnesium but also aluminum, plastic, or wrap it with a carbon composite material. Their new technique allows the researchers to create much more complex objects and also reduces the pore size from 0.5 mm to 0.1 mm.

From basic research to practice

This work is set up to go beyond purely academic purposes. Kleger and Fehlmann started the Pioneer Fellowship in early July. They have a year to prove whether the technology can be commercialized.

“We wanted to find out if the process could pass real-world usage testing,” says Kleger. She Business Partners Equal care is taken to ensure that the test results are not simply dust collection in a drawer. “It’s important for me to always have an app, because that keeps me motivated,” says Fehlmann.

For use in functions and in space

The two researchers had some concrete ideas for commercializing their process. One possible application is jaw implants.

Kleger explains: “If a person loses a tooth, the jawbone underneath will disintegrate very quickly. Before placing a dental implant, the bone must first be restored. Surgeons currently do this using bony material from the hip – but that requires a second surgical site.

Alternatively, they can opt for a custom bone implant made of magnesium alloy, in which the bone-forming cells can move and which will degrade over time. Kleger and Fehlmann were able to use their process to manufacture exactly this type of implant.

One idea going in a similar direction is to manufacture three-dimensional scaffolds for cell culture. Cells do not behave in the same way in 3D as they do on a 2D plane, such as a standard Petri dish in a laboratory. With this in mind, the researchers contacted scientists who work with such cell culture methods in the lab. It remains unclear whether these scientists would prefer to manufacture such scaffolds themselves using Kleger and Fehlmann’s process or would instead choose to purchase ready-to-use scaffolds.

Two young entrepreneurs see another possible use in space travel. “In space missions, weight is money,” says Kleger. Because it’s by the gram, the light metal components produced by their process would be ideal for use in spacecraft or rockets.

Customized, not mass production

However, one thing was clear to these two pioneering Fellows: their products would not be cheap mass-produced items, but relatively expensive mass-custom products. This is because the production process is quite slow and does not allow for large batches to be produced in a short time. “We will not put ourselves in the position of mass marketFehlmann said.

They have yet to make a final decision regarding their business model. “We are currently analyzing the market to find out our potential customers and what they really need,” explains Kleger. They have had countless discussions with dentists and cell biologists, and also with companies that make printing devices.

Deep learning curve in business

“What we’re doing now in some areas is very different from my PhD project – and the learning curve is correspondingly steep,” laughs Kleger.

Fehlmann adds, “We’re getting a lot of new input and we’re having to approach things differently than we do in research. That’s rich and exciting.”

The two women are also receiving start-up help from ETH Professor André Studart, in which the Complex Materials Group they conducted their research. Among the things he will offer them next year are lab work and printing equipment. “We are delighted that we can continue to work here for a while,” Kleger said.

Furthermore, they will benefit from the experience of other startup founders from Studart’s team. “We are in close contact with all four companies that have emerged from the group so far,” says Kleger.

They also came up with a name for their startup: “Sallea,” a compound word for “washed salt.” So the process they wanted to bring to market gave the fledgling company its name. At some point, they will apply for the “ETH spin-off” label. But for now, there’s still a lot of development work to be done — and then the two Pioneer Fellows will see if their successful research turns into a profitable company.