Quantica develops high viscosity printhead

Recently I have come across an interesting company called Quantica, which operates in the 3D printing market but has taken a unique approach by developing its own inkjet printhead, as well as a printer, whilst concentrating on niche applications.

Earlier this year I met with Ramon Borrell, who was formerly the chief technology officer for Xaar and is now CTO for Quantica. He says that most 3D printers can only print one material at a time and that this is quite a serious limitation for many applications, noting: “The world is multi-materials, there are layers and combinations.” 

The company, which is based near Berlin in Germany,  was founded in 2018, principally by Ludwig Färber. He was previously the CTO for Next Dynamics, another German company that also claimed to have developed a multi-material 3D printer. Next Dynamics closed down after problems raising funds through a Kickstarter campaign. Färber told me: “While I have my share of responsibility a lot of it was also related to excessive investor pressure. We decided together with Kickstarter to take down the campaign and no one lost money and no damage was made to the community of backers.”

Not surprisingly, he took a different approach with Quantica, opting to develop the technology first before going public. Consequently Quantica has been supported through venture capital funding for the initial product development stage and only started making public announcements in October 2021. One of those investors is the current CEO Claus Mosehelm. Borrell explains the approach: “We share development costs through NRE (Non-recurring Engineering) agreements with partners and share the profits with those partners. We will also distribute our own products.”

Borrell, who is also a small investor in the company, is adamant that there is no appetite for the company to be taken over by a larger player, stressing instead that the business model is to work with industry partners who can help fund the R&D. However, he suggests that an IPO would give the company some protection given the tendency in the still-young 3D printing world for larger, more established players to gobble up smaller, more innovative companies.

Quantica has so far filed three patents with another two pending. The company currently employs roughly 30 staff, mostly in R&D. The company is looking to expand its workforce this year to around 50 and by the end of 2024 to increase this to around 75. Borrell says: “Our philosophy is to hire top talent no matter what it costs because the applications are quite demanding.”

The original intention was to develop an inkjet system to produce Printed Circuit Boards or PCBs. But Färber couldn’t find a printhead that could run the type of materials he wanted to use without compromising on performance so he set out to design his own. He adds: “None of Quantica’s technology is related to my prior ventures. The printhead technology was developed after Next Dynamics closed down.”

NovoJet printhead

Quantica’s NovoJet printhead technology is quite unique though it’s essentially a piezo-electric head with a large amount of PZT . Most printheads work by creating small movements around the ink chamber to force out small drops of ink or fluid. This means that the ink needs to have a very low viscosity. Most printheads will struggle with anything over 20 mPa.s and most graphics inks aren’t anywhere close to that, with an average being around 6-8 mPa.s despite the recent tendency towards higher pigment loadings in a lot of applications. But many industrial applications require functional fluids, which might contain high concentrations of high molecular weight polymers or a high load of solids that make for a highly viscous fluid that is difficult to jet through a conventional printhead. 

So the NovoJet was developed specifically to handle such high viscosity materials. Borrell explains: “There is a huge amount of value above 100 mPa.s. There are a lot of materials that have been formulated for use in industrial applications and being able to use them in inkjet has enormous value.”

The head is made through conventional laser cutting, milling and micro machining. The current version has a single row of 88 nozzles with a 1.1 mm native nozzle pitch. The nozzle itself has a 60 micron aperture and can produce drops from 25pl to 600pl. It can handle fluids from 1-250 mPa.s. It has a jetting frequency of 4.8 kHz. The horizontal resolution is 600 dpi, with the vertical being 1200 or 1800 dpi, depending on the drop size.

At its heart is a virtual chamber, made of the space between the nozzle plate and a roof piston with the perimeter open to a local manifold area. The openness of the design provides fast refill even with high viscosity fluids. It also allows for full recirculation to the back of the nozzles at a high flow rate. Quantica says that it has been able to jet fluids containing up to 40 percent of 4um inorganic particles by volume. 

In order to jet these materials, the piston is driven hard towards the nozzle, forcing the fluid through the aperture. The drop size can be controlled by adjusting the amount of the displacement of the virtual chamber roof, by modulating the voltage applied to the piezo-electric actuator. Borrell explains: “It’s like hitting a tube of toothpaste with a hammer. Whatever is there is going to jet. Almost anything that is fluid is going to jet in that operation.” 

This requires a very large deflection, with makes for a very long vibration plate of 10mm compared with the more common 1-2mm of most piezo printheads. Quantica says that there is the potential to drive each nozzle independently by applying different voltages to each actuator to fine tune the drop volume. 

The nozzle plate is made of Nickel alloy, though Quantica is looking at other materials including polyamide and silicon. There is a heating element laminated onto the nozzle plate assembly and closed loop control over the temperature through an embedded thermal sensor. 

The nozzle plate is especially sensitive to cooling materials, so there’s a nozzle guard that includes a cleaning mechanism. In addition, there’s a membrane to separate the nozzles with degassing extracted inside the printhead through this membrane. The same system helps maintain the back pressure on the nozzle because it’s a closed system. 

The Novojet printhead does need quite wide spaces between nozzles and this in turn limits the number of nozzles and therefore its productivity so there is a trade off that limits its suitability to certain applications. Borrell says: “We will be close to 100 nozzles but we are still debating. More nozzles means more cost in the system but also more productivity so we need to find the right balance.” He adds: “Increasing the nozzle density is our number one aim for the next few years.”

Quantica has shown a roadmap that lists future printheads with multiple rows of nozzles with 208 and 624 nozzles, able to jet both single and multiple materials. Borrell says: “We think about different possibilities in moving to thin film but we might lose some of the capabilities to have high viscosity. So the question is how much can we afford to give up? Can we design a printhead with 1200 nozzles or more but limited to 350 mPa.sec?” Nonetheless, it’s worth noting that Quantica has picked up some of the former Xaar staff who had worked on its 5601 thin film printhead.

The printhead is guaranteed for one year with certified fluids, which Borrell says is around 30 billion drops per nozzle. The head itself measures 130 x 18 x 25mm. The head has a very compact design and Quantica plans to introduce this head in 2023 in a proprietary desktop printer. Quantica says that the design is scalable with no limit on the length or height. 

Borrell notes: “We manufacture the printheads ourselves and we can scale up to match production. We can produce tens of these because it’s still a niche application.” He adds: “The printheads are relatively simple. We outsource a lot of the parts. We have designed it for that.”

The first generation of these heads will be able to jet resins with suspended particles. The next generation is planned to print abrasive and high-particle-loaded resins and enable various functional applications in different material combinations. This includes biodegradable materials that are suitable for single-use applications, as well as bio-based material sources such as algae and plant-based substances. There are also bio-compatible materials that would be suitable for a number of medical applications.

There was certainly quite a lot of interest in this technology at ESMA’s recent Industrial Print Integration conference, where Borrell talked about it. Quantica has mainly concentrated on 3D printing applications but it’s clear that the ability to jet high viscosity materials will also be suitable for a number of industrial applications. There’s a second half to this story, which I will publish in a few days, where we will look at the 3D printer that Quantica is developing and some of the potential applications for this technology. In the meantime, you can find more details from quantica3d.com.