Expert Interview: Lithoz’s CEO Dr Johannes Homa on the State of Ceramic 3D Printing
03 June 2020
Ceramics 3D printing is still a relatively new additive manufacturing technology. However, despite its novelty, ceramic 3D printing is finding its way into many industries, from medical and dental, to aerospace and luxury goods.
Currently, only a handful of companies are developing 3D printing technology for ceramics. One such company is Austrian manufacturer, Lithoz.
We caught up with Lithoz’s CEO and Founder, Dr Johannes Homa, to discuss the current state of ceramic 3D printing, some of its exciting applications and the benefits of 3D printing as a digital manufacturing technology.
Can you tell us a bit about Lithoz and your mission as a company?
Lithoz is a technology provider for 3D printing of high-performance ceramics, which means we’re developing and selling machines, software and materials for 3D printing of ceramics.
We’re clearly the world market and technology leader in this field.
In addition to technology development, we also support our customers in the area of application development.
Neither the AM community nor the ceramic industry was used to ceramics 3D printing. We’re supporting both sides as much as we can.
How did you come to found Lithoz?
The technology was developed at the Vienna University of Technology, back in 2006, in collaboration with a dental company Ivoclar Vivadent AG.
Then in 2010, we achieved a breakthrough: we were able to 3D print ceramics with the same material properties as in conventional forming technology. This milestone encouraged us to spin out Lithoz as a company for 3D printing of high-performance ceramics.
Can you expand a little bit on the technology Lithoz has developed?
Our technology is based on a photopolymerisation process, which is very similar to conventional Stereolithography. The difference is that with our technology, the ceramic particles are dispersed into a photosensitive resin.
During the printing process, this composite material is solidified by light, layer-by-layer. The part that comes out of our 3D printer is called a green body, which means that it’s not a finished product yet.
The green body must undergo a heat treatment that involves baking a part in a specialised oven. In technical terms, we debind and sinter the part to achieve the desired properties of a ceramic part.
In the process of debinding, you burn off the binder and then you sinter the ceramic to full density. The part undergoes shrinkage, but this is a normal phenomenon in ceramic forming processes.
Can you share some examples of the applications that have been achieved with your technology?
We’re active in three different industries. The first one is medical, where we have resorbable and non-resorbable implants and medical devices. For example, resorbable implants have been in use since 2017. Non- resorbable implants are, on the other hand, bio-inert, which means that they do not react with the human body.
Additionally, the heat conductivity of ceramics is rather low. So, another benefit of ceramic implants, compared to metal ones, is that people don’t feel pain when they are in direct sunlight or when they take hot showers.
The third medical application is medical devices, where you need some isolating, non-magnetic properties of the ceramics. Ceramics are ideal for the medical industry because they are bio-inert and don’t provoke allergic reactions, which might be the case with metals or plastics.
Another area we’re focused on is casting cores for turbine blades. Turbine blades feature an internal cooling system to cool down the blade during operation. With the growing trend towards increasing efficiency by increasing the temperature, the designs of such cooling systems have become more sophisticated.
The level of sophistication means that the designs cannot be injection moulded anymore, requiring a new manufacturing approach to be able to produce them. Additive manufacturing proves an ideal solution for these cores.
Another area of focus for us is technical ceramics. These are advanced ceramic materials used in everything, from satellite components, like mirror holders and radio frequency components, to mechanical engineering parts, for example, for textile machinery and semiconductor machinery.
So, this means there is a wide range of applications for our technology, including luxury goods.
Can this technology be also used with metals?
That’s a great question.
Our philosophy is that we are adapting our technology to the powder and not vice versa.
So, it means that we were able to adapt our technology to metals. We were so successful that we even made a spin out of the company.
Now there’s a company called Incus, and it’s doing metal 3D printing using a photopolymerisation approach. With this technology, it can achieve high resolutions, good mechanical properties and high precision, making parts comparable to metal injection moulded parts.
What is the current state of ceramic 3D printing in terms of understanding the technology?
Ceramic 3D printing is one of the youngest technologies in 3D printing, so the knowledge base is not yet so well developed.
That said, just today I received an email from a customer who had a meeting with their C-level executive who was surprised that the potential for 3D printing ceramic parts in their company was larger than for metallic parts.
We see that there are a lot of applications, but ceramic AM is not yet so well known in the 3D printing industry.
This is starting to change, though. People have seen that there are limitations with plastics and metals, which can be overcome by ceramics.
How would you advise a company that is looking into the potential of either ceramic 3D printing or 3D printing more generally, but doesn’t know where to begin in terms of adopting the technology?
This is a very difficult question because the business case is usually not just right on your desk. The easiest way to get started is to explore 3D printing for prototypes. This way will allow you to start learning the technology.
Then, you’ll start talking with customers and looking into your portfolio to identify which parts make sense to 3D print. The biggest challenge is to find a part suitable for additive production. From a design perspective, this part should be very sophisticated and ideally cannot be produced by other technologies.
Once you have found it, you have a competitive advantage. To summarise, it’s not just low hanging fruits that you are looking for, but it’s a project which you set up in your company. And it should be rather from the top-down and not from the bottom up.
It can be hard to see the full potential of AM at the beginning. Any company adopting 3D printing must put in some effort to dig out this potential. But once you have found a suitable use case, it will open many doors for you.
What are some of the challenges involved in 3D printing ceramics?
One issue that we often face is that people want to 3D print parts, which are already well-established in conventional forming technologies. As a result, they’re surprised that additive manufacturing tends to be more expensive than more conventional technologies.
What needs to be understood is that reproducing a traditionally manufactured part with the help of 3D printing, won’t make it cheaper in most cases.
Another challenge is that we cannot overcome material science issues with the help of additive manufacturing. AM is just a forming technology. It doesn’t overcome issues for sintering, which is mandatory for ceramic processing.
For example, it’s easy to 3D print multi-material ceramic parts. But it would be challenging then to co-sinter these materials. I think such considerations are sometimes underestimated.
A recent report by SmarTech Analysis states that the growth of ceramic 3D printing will be largely driven by end-part production. What are your thoughts on that?
I totally agree. When we started 10 years ago, nobody had an idea of high-performance ceramic 3D printing. And now we see so many applications that even we were not aware of.
I strongly believe that ceramics are the materials of the future and we’re only at the very beginning of this journey. Over the past 10 years, we’ve had to show and to prove that 3D printing is also possible with ceramics, and now people are beginning to take advantage of this technology.
What I also think people are starting to realise now is that digital technology, such as AM, can be a solution to lockdowns, thanks to digital inventories possible with the technology.
Can you expand a little bit on how digital technologies and 3D printing can provide support to companies?
During the COVID-19 crisis, there has been a lockdown of certain suppliers. For example, in injection moulding, a supplier has the tool and if you want to produce a part again, you go to your supplier and ask him to manufacture more parts for you and he will do so in a normal environment.
But the situation with COVID-19 makes the global supply chain much more fragile and disrupted now. Many companies cannot reach out to their suppliers or the suppliers cannot produce parts.
On the other hand, with additive manufacturing, the only tool you’re using is the machine itself. The machine can be here in Europe, or the United States, in Asia, in any place basically, and all you need is just to transfer the data to the machine and print the part immediately, without having any tools.
Of course, you need to qualify the part for AM, but, overall, the technology gives you much more flexibility.
Another point is that the digital nature of AM enables you to store design files in virtual storage, instead of a physical inventory, and print them on demand.
How do you see the evolution of ceramics 3D printing in the next few years?
I think there is great potential ahead. That said, in contrast to other AM technologies, ceramic AM has, from the very beginning, to fulfil the requirements of a high-quality part.
Because if you need a ceramic part, it must have the same material properties as in conventional manufacturing, even if it’s just a prototype. That’s because you would use it in a harsh environment, like high temperatures or a corrosive environment.
If you want to have a visual prototype, you would not make it out of ceramics, you’d make it out of plastic. You always want to have functional prototyping with ceramics AM, so from the very beginning we were doing the production of lot size one.
What does the year ahead hold for Lithoz?
We see two different consequences of the pandemic for our business.
Firstly, we’ve seen a smaller group of our customers taking a pause in additive manufacturing and focusing on other things.
In another group, we see more companies now looking much more into additive, because of the benefits of digital production technology, like digital warehousing and the possibility to stabilise their supply chain.
While the current situation is bad for the world economy, I see companies now realizing the potential of additive manufacturing, because people start to think differently and considering digital production technologies as a means to overcome these issues.
For Lithoz, we don’t think that this crisis will have a big impact on our revenue and sales. The future is very bright for us.
We have a lot of projects underway which we currently can’t disclose. They will come up in the future and people will be very surprised about what’s already possible with ceramic 3D printing.