Researchers at ETH Zurich, in collaboration with Inkbit 3D, have pioneered 3D printing of soft robots with artificial bones, ligaments, and tendons.
3D printing has advanced so rapidly that researchers have successfully been able to mimic bones, ligaments, and tendons into a robot hand.
To achieve these Westworld-reminiscent results, a team of researchers from ETH Zurich collaborated with the US startup Inkbit 3D.
The technological breakthrough enabled the team to 3D print a variety of high-quality materials in a single process, resulting in more durable robots.
“We wouldn’t have been able to make this hand with the fast-curing polyacrylates we’ve been using in 3D printing so far,” said Thomas Buchner, a doctoral student in the group of ETH Zurich.
Slow-curing plastics offer several advantages in 3D printing. They help minimise internal stresses that can lead to warping and shrinkage in the printed object.
Additionally, the slower curing process can result in stronger and more durable prints, as each layer has more time to securely bond with the previous one.
More durable, soft-robots
“These [slow-curing plastics] have very good elastic properties and return to their original state much faster after bending than polyacrylates,” added Buchner, making them ideal for creating the robotic hand.
“Robots made of soft materials, such as the hand we developed, have advantages over conventional robots made of metal,” said Robert Katzschmann, robotic professor and first author of the study published in Nature.
“Because they’re soft, there is less risk of injury when they work with humans, and they are better suited to handling fragile goods,” Katzschmann added.
3D printing technology appeared in the 2010s and creates objects by building them layer by layer.
In this process, nozzles deposit a specific material in a viscous state at each point, and an ultra-violet (UV) lamp promptly cures each layer. However, this approach is not feasible with slow-curing plastics, as it would cause the scraper to become ineffective due to gumming up.
To accommodate the use of slow-curing polymers, the researchers enhanced 3D printing by incorporating a 3D laser scanner that immediately checks each printed layer for surface irregularities.
This innovative approach means that instead of smoothing out uneven layers, the new technology considers the unevenness when printing the next layer.