From the abstract:
"...feature resolution below 100 micrometers. ... complex solid parts can be drawn out of the resin at rates of hundreds of millimeters per hour."
Key novel feature is the oxygen-permeable, UV-transmitting membrane at the bottom of the tank that creates a thin (down to 20um) inhibited 'dead zone' where the resin can't polymerize. They project the image for the current layer up through the membrane and the dead zone, so the build layer is actually within the tank. This means they can just draw the part up continuously from the top, with no stepping or processing needed after each layer. The thickness of the effective build layer can be controlled by adding a UV light-absorbing dye to the resin, which allows them to optimize for different print speeds.
I didn't see in the supplementary materials, does anybody know if they are using a pressurized air or oxygen source to increase oxygen flow through the membrane?
edit: to repond to my own Q: they can use both pressurized oxygen and pressurized air. Using pressurized air decreases the dead zone but still very workable.
it's like a laser printer but instead of toner it uses gooey resin. project (in UV light) a shape on the bottom of the goop and it will start to solidify in that shape (once it touches oxygen)... so gently pulling some solid surface goop out gets you to the point where you can "print" stuff! Pretty cool! It's not clear to me if the resin solidifies only on contact with UV light and the oxygen level is controlled from below or above, but at any rate the balance of UV light (in a particular projected design) and oxygen is what makes this possible.
I think the oxygen prevents solidification which is what stops the object from sticking to the screen they project the image on to. By the looks of it the oxygen just diffuses from the air through the screen.
First carefully consider what you want to print. For example, this resin type printer is not a great technology for creating strong replacement parts around the house.
It will apparently be the cover story. (Does this count as Sequoia breaking Science's embargo?): https://twitter.com/sequoia/status/577651625545748480
From the abstract: "...feature resolution below 100 micrometers. ... complex solid parts can be drawn out of the resin at rates of hundreds of millimeters per hour."
Key novel feature is the oxygen-permeable, UV-transmitting membrane at the bottom of the tank that creates a thin (down to 20um) inhibited 'dead zone' where the resin can't polymerize. They project the image for the current layer up through the membrane and the dead zone, so the build layer is actually within the tank. This means they can just draw the part up continuously from the top, with no stepping or processing needed after each layer. The thickness of the effective build layer can be controlled by adding a UV light-absorbing dye to the resin, which allows them to optimize for different print speeds.
Here's a relevant patent, issued in 2014, listing the 3 founders of carbon3D (formerly EIPI systems): http://www.freepatentsonline.com/20140361463.pdf
And... founder Joe Desimone also gave a Ted Talk tonight, so soon we'll even get to see a splashy 18-minute long talk about the technology. https://conferences.ted.com/TED2015/program/schedule.php