Malleable Structure Increases Robot Arm Movement Without Adding Extra Parts

Traditional robot arms are made of a combination of long straight tubes and actuated joints. More tubes and joints (or degrees of freedom) can be added to increase the robot arm’s movements, but it makes the robot more complex, heavier, and expensive. Researchers from Imperial College London’s REDA Lab took this traditional rigid structure, and they combined it with soft robotics elements for a malleable structure that improves versatility without adding more degrees of freedom.

The arm is made up of layers, and layers of Mylar sheets cut into flaps and stacked on top of each other, so each flap is overlapping. Because the Mylar is slick, the flaps can move smoothly against one another, which lets you adjust the shape of the arm. Latex membranes surround the flaps, so when air is pushed out from between them, the flaps will press down on each other and lock the structure into its current state. This combination of a soft and rigid robot gives it more flexibility without the control problems.

The team used motion-tracking sensors and distance geometry to obtain the forward and inverse kinematics of the robot, which we can use to control the robot’s gripper. In the future, they hope this is something the robot will be able to do on its own.

Though the system has many advantages, there are still hurdles to overcome, such as the malleability being weaker than a rigid steel link. But this is an issue the researchers are hoping to solve as they continue working on the robotic arm. They hope to refine the kinematics of the robot for a more robust and complete system that allows you to reshape it while operating with the accuracy expected from robotic systems.