Low-cost artificial ‘muscles’ developed for safer, softer robots

Stand aside Arnold Schwarzenegger, a new kid is in town ready to flex his muscles.

Engineers have developed a low-cost artificial actuator that moves by expanding and contracting just like a human muscle.

The breakthrough from a team at Northwestern University means that low-cost, simplified soft actuators enable worm-like crawling and bicep-like lifting.

The researchers have demonstrated the actuator in a crawling soft robot and an artificial bicep. The soft actuator stiffens like a human muscle, a property that historically has been missing from soft robotics.

To demonstrate the actuator, the researchers used it to create a cylindrical, worm-like soft robot and an artificial bicep. In experiments, the cylindrical soft robot navigated the tight, hairpin curves of a narrow pipe-like environment. The bicep was able to lift a 500-gram weight 5,000 times in a row without failing.

Crucially, because the researchers 3D-printed the body of the soft actuator using common rubber, the resulting robots cost about $3 in materials, excluding the small motor that drives the actuator’s shape change.

This sharply contrasts with typical stiff, rigid actuators used in robotics, which often cost hundreds to thousands of dollars.

The new actuator could be used to develop inexpensive, soft, flexible robots, which are safer and more practical for real-world applications.