Earlier this month, Carbon3D was named one of the World Economic Forum’s Technology Pioneers. Past recipients include Google (2001), Wikimedia (2007), Mozilla (2007), Kickstarter (2011) and Dropbox (2011).
Carbon3D recently announced that they have secured an unprecedented $100 million dollars in a Series C investment round led by Google Ventures. Other investors include Yuri Milner and Reinet Investments S.C.A.
Not since ENGINEERING.com has been covering 3D printing has this much money poured into a 3D printing startup. What is the significance of such an investment?
What Is CLIP?
Basically, Carbon3D's investors are banking on CLIP technology being the driving force that will transform 3D printing from a mostly prototyping technology into a true manufacturing technology. If you look at their early adopters, you will find that two companies, Ford Motor Company and Legacy Effects, have used Carbon3D's CLIP for very different reasons.
The CLIP method was co-invented by the CEO of Carbon 3D, Joseph DeSimone, a chemistry professor at University of North Carolina-Chapel Hill, along with colleagues Alex Ermoshkin, CTO of Carbon 3D, and Edward T. Samulski, who is also a professor of chemistry at UNC. According to their Continuous Liquid Interface Production of 3D Objects, from the March 2015 issue of Science magazine: “When stereolithography is conducted above an oxygen-permeable build window, continuous liquid interface production (CLIP) is enabled by creating an oxygen-containing 'dead zone,' a thin uncured liquid layer between the window and the cured part surface. We show that dead zone thicknesses on the order of tens of micrometers are maintained by judicious selection of control parameters (e.g., photon flux and resin optical and curing properties). Simple relationships describe the dead zone thickness and resin curing process, and, in turn, result in a straightforward relationship between print speed and part resolution. We demonstrate that CLIP can be applied to a range of part sizes from undercut micropaddles with stem diameters of 50 μm to complex handheld objects greater than 25 cm in size."
The key to understanding CLIP technology is to realize that it removes three steps common to an SLA DLP printer. What happens is that the oxygen-permeable window used in the CLIP method eliminates repetitive separation, re-coating and re-positioning of the print that occurs with traditional SLA 3D printers.
What may be misleading about the Carbon3D printer is that it looks like a desktop 3D printer. At TED (as an ENGINEERING.com reader named Diego pointed out to me), you only see the resin vat sitting on top of the light projector. If the light projector fit inside of the stand at TED, it could be as large as a 35,000 lumens projector such as the Mirage 4K35, which costs around $150,000 dollars.
How many lumens does it take to power a Carbon3D printer? From there, we will know whether or not this is an industrial 3D printer or desktop printer. How big is the Carbon3D footprint?
Biomedical Application
And what about some of the language in the patent? Is the Carbon3D printer a medical 3D printer?
"In some embodiments, the polymerizable liquid may carry live cells as 'particles' therein. Such polymerizable liquids are generally aqueous, and may be oxygenated, and may be considered as 'emulsions' where the live cells are the discrete phase. Suitable live cells may be plant cells (e.g., monocot, dicot), animal cells (e.g., mammalian, avian, amphibian, reptile cells), microbial cells (e.g., prokaryote, eukaryote, protozoal, etc.), etc. The cells may be of differentiated cells from or corresponding to any type of tissue (e.g., blood, cartilage, bone, muscle, endocrine gland, exocrine gland, epithelial, endothelial, etc.), or may be undifferentiated cells such as stem cells or progenitor cells. In such embodiments the polymerizable liquid can be one that forms a hydrogel..."
This is interesting to me because of the medical company that Joseph DiSimone founded in 2004, Liquidia Technologies. DiSimone founded Liquidia Technologies based on discoveries he made at his UNC chemistry laboratory to help deliver drugs, vaccines and other treatments in a more targeted an less wasteful way. Using advanced lithographic techniques from the semiconductor industry, he created a highly advanced product development and manufacturing platform known as the Particle Replication in Non-Wetting Templates (PRINT) platform. This is interesting because a DLP projector works by shaping light with digital micromirrors laid out in a matrix on a semiconductor chip. Light curing creates the shape in CLIP technology, but the chemical-tuning creates the mechanical properties. So what about the Carbon3D resin material? What is it exactly?
In the video on Liquidia's homepage, they mention something called "fluorecures" (though I couldn't find the name in print), which could mean curable fluoropolymers, which are very desirable in photochemical processes like the CLIP method because of their ability to withstand harsh chemical environments and high temperatures. Further study of the patent shows they use an amorphous flouropoylmer called Teflon AF among other materials. Teflon AF is sold in resin form at $1800 per 25 grams. According to Chemours.com, "The Teflon AF amorphous fluoroplastics are distinct from other fluoroplastics in that they are soluble in selected solvents, have high gas permeability, high compressibility, creep resistance, and low thermal conductivity. Teflon AF polymers have the lowest dielectric constant of any known solid polymer and the lowest index of refraction of any known polymer."
Based on its properties, AF Teflon seems ideally suited for the role of semipermeable membrane where oxygen is used to control the polymerization rate and process. The mechanical properties of cured fluoropolymers are make it desirable for injection molding. Fluoropolymers are sturdy, low-maintenance and heat-resistant.
More research is to be done, but between keeping resin levels automatically regulated, using a possibly high power (maybe 35,000 lumens) DLP projector, super-expensive materials and a regulatory process that more than likely requires a precision motion control system (similar to those used at Liquidia), this 3D printer is definitely not your average desktop printer in price or capacity.
Ford Motor Company used CLIP technology to fabricate elastomer grommets 66 percent faster than other 3D printers with more accuracy to desired mechanical properties. Special effects company Legacy Effects used it to fill last minute orders for a Progressive Insurance commercial. Other than that, we know it may become commercially available early next year.
It's a safe guess that the fast Carbon3D printer shown at TED 2015 will be extremely cost prohibitive, especially compared to other desktop 3D printers, which is what most people assumed it was at first. If the build volume were the same as a Fortus 450mc for example, then the huge price tag might be worth it. But we don't know the price tag, and probably won't for a while.
Stay tuned for Part 2. In the meantime, do you fall in line with Silicon Valley's confidence about Carbon3D?