This Robot Hand Can Play Piano Without “Muscles,” and It’s 3D-Printed!

Robotics, like many other engineering fields, can be approached in two different ways: with complexity, or with ingenuity. If an engineer wants a robot to walk like a human, they could use dozens of servo motors and intricate control systems. Or, they could take advantage of the innate physical properties of construction materials to simulate biological tendons, bones, and ligaments. It’s more difficult, but far more elegant. That’s the same approach that University of Cambridge researchers took with this piano-playing robot hand.

The 3D-printed skeletal hand is attached to a conventional industrial robot arm, but doesn’t actually have any actuation itself. There are no motors or solenoids acting as muscles on the hand. Instead, the robot is able to play piano with the hand by relying entirely on its physical properties. The hand was 3D-printed with varying flexibility, which enables “embodied intelligence” through interaction with the world using a passive component.

Embodied intelligence in a robot can be thought of like body parts evolved in nature. The shape of your ear, for example, evolved to pick up a range of frequencies passively, so you don’t have to actively change its shape. In the same way, this robot hand was designed for the complex task of playing a piano without actively altering the shape of the hand. As you can see in the video, the robot is still able to use that hand to play piano simply by moving its arm. Ultimately, this design philosophy could lead to robots that are more capable, while also being less expensive and more resilient.