While 3D printers can now build homes, entire robots, skin, and even cheesecakes, they’ve been fairly limited when it comes to the world of soft robotics—which are robots that are made of more flexible yet strong materials. This is primarily due to the fact that much of 3D printing technology relies on fast-curing plastics (also called polyacrylates) that quickly harden once printed.
While this is good for making, say, a set of dice for Dungeons and Dragons or a bottle opener, it’s less ideal for things like creating prosthetic limbs. That’s why an international team of researchers in Switzerland and the U.S. have created a new 3D printing process that allows users to create more elastic materials along with rigid ones using slow-curing polymers.
The team published a paper Wednesday in the journal Nature where they were able to use the system to create a 3D printed hand complete with bones, ligaments, and tendons. The new process also utilizes a laser sensor array developed by researchers at MIT that allows the printer to actually “see” what it’s creating as it creates it.
ADVERTISEMENT
“We wouldn’t have been able to make this hand with the fast-curing polyacrylates we’ve been using in 3D printing so far,” Thomas Buchner, a robotics researcher at ETH Zurich and lead author of the paper, said in a statement. He added that the slow-curing polymers that they’re using for this process “have very good elastic properties and return to their original state much faster after bending” than the fast-curing plastic.
A typical 3D printer works by using a series of nozzles to layer the fast-curing plastic in the shape of the object you’re printing. As it does so, a UV lamp shines on the object and rapidly cures each layer. While this process works well for rigid objects, it does require any imperfections to be scraped off after each cure. Otherwise, it risks ruining the final product.
The researchers incorporated a 3D laser sensor that scans each layer for irregularities. When the device detects any, it makes adjustments when printing the next layer “in real time and with pinpoint accuracy,” Wojciech Matusik, a robotics professor at MIT and co-author of the study, said in a statement. This does away with a need for a scraper as the device takes the irregularities into account.
Using this method, they can develop soft robotics for potential prosthetics as well as machines that can be used in various industries and scenarios like shipping and packaging. “Robots made of soft materials, such as the hand we developed, have advantages over conventional robots made of metal,” Katzschmann said. “Because they’re soft, there is less risk of injury when they work with humans, and they are better suited to handling fragile goods.”
The team now hopes to refine the design to create even more complex structures. Meanwhile, the device will also be commercially available from a startup called Inkbit that plans to sell it both as a 3D printing service and product.
The device can be seen as the next evolution of 3D printing. Not only can they create rigid objects, but now they can create softer and more sophisticated designs that can, quite literally, lend you a helping hand.
