This Artificial Muscle Can Turn Robots Into Superheroes—Or Supervillains

Flexible design inspired by origami can lift 1,000 times its weight.

Scientists at the Computer Science and Artificial Intelligence Laboratory at MIT and the University of Harvard’s Wyss Institute have developed a new type of artificial soft muscle that is incredibly flexible and light but capable of lifting 1,000 times its weight. MIT CSAIL director Daniela Rus claims that equipping robots with these muscles will be “like giving [them] superpowers.” Cue the Terminator 2 theme.


Most soft artificial muscles have a problem: The softer and more flexible the muscle, the less strength it has–and vice versa. This greatly reduces their usefulness. A potential human arm replacement, for example, wouldn’t be able to exert the same kind of power as a real human arm.

The CSAIL and Wyss project changes the strength-power relationship. ” In their tests, a muscle weighing only 0.09 ounces lifted 6.6 pounds. To help you visualize it, this is the equivalent of “a duck lifting a car,” according to the researchers.

The paper, published this week in Proceedings of the National Academy of Sciences, describes an origami-inspired design that uses two parts: a flexible skin that surrounds a folded structure made of hard materials (acrylic or metal) or semi-soft materials (like molded rubber). The structural geometry of the fold gives the muscle a characteristic motion. Since origami can adopt multiple geometries from a flat sheet of material, scientists can “program it” to perform any action they want, in one direction or multiple simultaneous directions, like you see in this animation:

[Image: Harvard’s Wyss Institute]
According to team member Shuguang Li, this geometrical programming is why you don’t need electronics for motion control.”[H]ow the skeleton folds defines how the whole structure moves,” Li says in the note from MIT. “You essentially get that motion for free, without the need for a control system.” The team believes that the muscles’ “built-in intelligence” can greatly simplify robots in addition to turning them into super-powerful beings.

The concept is simple and elegant: Inside the skin, scientists put a fluid that can be air or water, which is a radical departure from existing soft muscle designs that “rely on vacuum rather than inflation to contract.” Absorbing or injecting fluid makes the bag contract or expand, which in turn makes the hard skeleton fold or unfold. When activated, the muscle can move to lift stuff in one dimension, softly grab other objects, or do a complex action like twisting the top of a mason jar, among other things.


[Photo: MIT CSAIL]
The researchers claim that anyone can build these muscles in under 10 minutes for less than a dollar. You would only need plastic folded in the geometry you want, a bag of plastic, a compressor, and water or air. They also say that this makes the muscles “cheap and easy to test” for a variety of applications–“from minimally invasive surgery and transformable architecture to deep-sea research to space exploration.” They are scalable, too. According to Rus, you could even build something weird and wonderful like an elephant robot “with a trunk that can manipulate the world in ways that are as flexible and powerful as you see in real elephants.” In fact, she claims this is exactly the next thing she wants to build with the technology.

The potential of these new muscles is amazing. Imagine a soluble micro-robot that releases drugs inside a part of your body, a soft exoskeleton to turn astronauts into alien-killing Ripleys, or buildings with walls that can move at will.

Unfortunately, I can also imagine an army getting its hands on this, developing it even further, and combining it with an evolution of an existing biped robot platforms like Atlas to build humanoids capable of lifting a tank off the ground and throwing it across a battlefield. Add some artificial intelligence and computer vision systems, a Skynet somewhere in the cloud, and you get yourself the entire kit for a dystopian nightmare. So yes, that MIT doctor better build and weaponize her hippie elephant. We are going to need it.

About the author

Jesus Diaz founded the new Sploid for Gawker Media after seven years working at Gizmodo, where he helmed the lost-in-a-bar iPhone 4 story. He's a creative director, screenwriter, and producer at The Magic Sauce and a contributing writer at Fast Company.