Fully functional robotic hand printed in one go

Swiss researchers have successfully printed a robotic hand with bones, ligaments, and tendons all in one go using a new laser scanning technique.

The robotic hand, embedded with sensor cavities and fully actuated, demonstrated immediate functionality post-printing, according to ETH Zurich. No additional assembly was required, it said.

The hand was shown gripping objects such as a marker and a water bottle. Researchers also printed other structures, including a six-legged robot capable of lifting and carrying a container.

Researchers said that entire robotic systems can be manufactured in a single process using a new 3D printing method, developed by MIT spin-off Inkbit and ETH Zurich.

Unlike earlier techniques that were limited to fast-curing plastics, this new method expands the material possibilities to include low-curing plastics, making it easier to combine soft, elastic, and rigid materials in 3D printing.

As a result, more complex and more durable robots made from a variety of high-quality materials can be printed. This opens new possibilities in the field of soft robotics, according to ETH Zurich robotics professor Robert Katzschmann, first author of the study published by Nature.

“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,” Katzschmann said.

The new technology also replaces a specialized device – which scraped off the surface of printed layers after each curing step to even out any surface irregularities – with a 3D laser scanner that simply takes the unevenness into account for the next step.

“A feedback mechanism compensates for these irregularities when printing the next layer by calculating any necessary adjustments to the amount of material to be printed in real-time and with pinpoint accuracy,” said Wojciech Matusik, an MIT professor and co-author of the study.

ETH Zurich said its researchers would use the technology to explore further possibilities and to design even more sophisticated structures and develop additional applications.

Meanwhile, Inkbit is now printing complex objects on customer requests and plans to sell 3D printers based on the new technology.