In 2015, MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) reported news that the lab had developed a unique multimaterial 3D printer capable of combining 10 different materials and integrating complex components, such as sensors and circuits, during the printing process. Perhaps most exciting was the fact that the system required only $7,000 in parts to build. Now, a bit of news has come across the wire indicating that MIT CSAIL’s MultiFab 3D printer may be going into production.
The MultiFab 3D printer combines machine vision and low-cost components to 3D print 10 materials at once. (Image courtesy of CSAIL.)
The MultiFab 3D printer fabricates objects by jetting up to 10 different photopolymers through piezoelectric inkjet printheads, which were removed from Epson WorkForce 30 office printers and adapted for 3D printing by the MultiFab team. After the printer deposits a layer of photopolymers, a UV LED module cures the photosensitive resins in a solid state. This process is continued until the object is complete.
In addition to combining 10 materials, the MultiFab also implements machine vision to create a closed feedback loop, possibly the first such feedback loop in 3D printing. By integrating an optical coherence tomography 3D scanner into the system, the printer is able to calibrate before a print, ensuring that the printhead is level and that the inkjets are calibrated. More importantly, the scanner can scan while a print is being performed, check for errors and create “correction masks” to adjust the printing process accordingly.
The use of machine vision gives the MultiFab another ability not easily made possible with existing 3D printers—the ability to 3D print onto or around complex components. After placing an “auxiliary object,” as the team calls them, onto the print bed, the 3D scanner can scan the object and adjust a CAD model to print around it.
To demonstrate the applications of such a technique, the team placed a smartphone onto the bed and printed a phone case directly onto the phone. Other more complex objects produced by combining 3D printing with complex components include microlens arrays, fiber optic bundles, LED lenses and more.
Multimaterial objects 3D printed with the MultiFab. (Image courtesy of CSAIL.)
The MultiFab 3D printer is groundbreaking both in terms of price and functionality. Stratasys recently announced the release of the J750, the company’s most advanced multimaterial PolyJet 3D printer so far. With the ability to blend six different photopolymers to create a seemingly endless variety of “digital materials,” the J750 can print parts with different colors, levels of transparency, flexibility, rigidity and toughness. Though the price of the system has not yet been made public, the previous PolyJet machine, the Connex3, is priced at over $250,000.
By using off-the-shelf components, the MultiFab team was able to reduce the bill of materials for the machine to just $7,000 while still achieving print resolution of just 40 µm. For instance, rather than gas-discharge lamps, the MultiFab has a more affordable LED light module, as well as a simple material feeding system. The computer vision feedback loop also compensates for potential issues with the software or hardware. The materials, too, are estimated to be only about $20 per kg, a far cry from $500 per kg of the Stratasys machines.
At the same time, the technology has the built-in ability to blend even more materials than the J750, integrate nonprintable objects into a print, 3D scan models and auto-correct while printing. What may be more exciting is that the MultiFab team has recently enlisted electronic product development company Tri-Star Design to design, test and integrate electronic hardware for the MultiFab machine. The systems that Tri-Star will be developing are the main system processing element, system power management and the printhead control functions.
Though the company has released little information about the contract, the move to develop custom components for the MultiFab hints that the makers of the machine are looking to move beyond the R&D stage to actual manufacturing. If the price of the MultiFab can remain at a level that is even less than $10,000, it could have a significant impact on researchers now and 3D printing in the future.