In robotics, increased flexibility and dexterity often means reduced strength, as softer materials are generally not as strong as rigid ones. However, researchers at the Wyss Institute at Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory have created origami-inspired artificial muscles, made from a variety of materials, that allows robots to lift up to 1000 times their own weight!

Each artificial muscle consists of an inner “skeleton” that can be made of various materials, such as a metal, plastic, or silicone rubber, folded into a certain pattern. The skeleton is surrounded by air or water and sealed inside a plastic or textile bag that serves as the “skin”. The muscles are completely programmable, meaning that designing how the skeleton folds defines how the whole structure moves.

A vacuum applied to the inside of the bag initiates the muscle’s movement, causing the skin to collapse onto the skeleton. This creates tension that drives the motion. No other power source or human input is required to direct the muscle’s movement; it is determined entirely by the shape and composition of the skeleton.

The team constructed dozens of muscles using materials ranging from metal springs to packing foam to sheets of plastic. They also experimented with different skeleton shapes to create muscles that can contract down to 10% of their original size, lift a flower off the ground, and twist into a coil, all simply by sucking the air out of them.

A single muscle can be constructed within 10 minutes using cheap materials. The origami-inspired muscles could be used, for instance, for medical devices, deployable structures, or wearable robotics.

Photos: Shuguang Li / Wyss Institute at Harvard University