Researchers have developed a new 3D inkjet printing system that makes it easier to combine soft, elastic, and rigid materials for the field of soft robotics.
The new 3D printer uses computer vision to automatically scan the 3D printing surface and adjust itself accordingly.
3D inkjet printers use thousands of tiny nozzles to deposit minute droplets of resin. Usually, these droplets are then smoothed with a scraper or roller and then cured with UV light.
The new system can ensure that areas have the right amount of material, contact-free, by adjusting the amount of resin each nozzle deposits in real time. This makes it possible to use slow-curing polymers – which have enhanced elastic properties and are more durable and robust than fast-curing one.
Using the new technology, researchers have successfully printed a robotic hand with bones, ligaments, and tendons made of different polymers in one go.
“We wouldn’t have been able to make this hand with the fast-curing polyacrylates we’ve been using in 3D printing so far,” explains Thomas Buchner, a PhD student at ETH Zurich, Switzerland.
“We’re now using slow-curing thiolene polymers. These have very good elastic properties and return to their original state much faster after bending than polyacrylates.”
Robert Katzschmann, professor of robotics at ETH Zurich, adds: “Robots made of soft materials, such as the hand we developed, have advantages over conventional robots made of metal. 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 findings are outlined in a study in Nature.