3-D-printed robot hand plays the piano

Scientists have developed a 3-D-printed robotic hand which can play simple musical phrases on the piano by just moving its wrist. And while the robot is no virtuoso, it demonstrates just how challenging it is to replicate all the abilities of a human hand, and how much complex movement can still be achieved through design.

The robot hand, developed by researchers at the University of Cambridge, was made by 3-D-printing soft and rigid materials together to replicate of all the bones and ligaments—but not the muscles or tendons—in a human hand. Even though this limited the robot hand’s range of motion compared to a human hand, the researchers found that a surprisingly wide range of movement was still possible by relying on the hand’s mechanical design.

Using this ‘passive’ movement—in which the fingers cannot move independently—the robot was able to mimic different styles of piano playing without changing the material or mechanical properties of the hand. The results, reported in the journal Science Robotics, could help inform the design of robots that are capable of more natural movement with minimal energy use.

Complex movement in animals and machines results from the interplay between the brain (or controller), the environment and the mechanical body. The mechanical properties and design of systems are important for intelligent functioning, and help both animals and machines to move in complex ways without expending unnecessary amounts of energy.

Robot hand playing Jingle Bells. Credit: Josie Hughes“We can use passivity to achieve a wide range of movement in robots: walking, swimming or flying, for example,” said Josie Hughes from Cambridge’s Department of Engineering, the paper’s first author. “Smart mechanical design enables us to achieve the maximum range of movement with minimal control costs: we wanted to see just how much movement we could get with mechanics alone.”

Over the past several years, soft components have begun to be integrated into robotics design thanks to advances in 3-D printing techniques, which has allowed researchers to add complexity to these passive systems.

The human hand is incredibly complex, and recreating all of its dexterity and adaptability in a robot is a massive research challenge. Most of today’s advanced robots are not capable of manipulation tasks which small children can perform with ease.