Artificial muscles could help robots lift 80 times their own weight

Boston Dynamics’ BigDog robot throws cinder blocks. NASA Jet Propulsion Laboratory’s RoboSimian swings on its lanky arms like a gymnast.

They’re strong robots, but they could be stronger. Like many other robots, they move with the help of hydraulics, a system based on pressurized fluid that causes them to be relatively slow and jerky in their motions. It also restricts them to lifting half of their own weight, which is in line with the average human.

National University of Singapore engineers have created a stretchy plastic that could be built into robots to serve as artificial muscle. The muscle would be activated by pulses of electricity, allowing a robot to react as quickly as a human muscle can. The team plans to file a patent for the plastic and pulse system.

Researchers have built plastic muscles controlled by electrical impulses before and bio-inspired robots with internal structures that resemble the human skeleton and muscle system, but the work out of Singapore hints at the strongest bots yet.

“Last year, we calculated theoretically that polymer muscles driven by electrical impulse could potentially have a strain displacement of 1,000 percent, lifting a load of up to 500 times its own weight. So I asked my students to strive towards this Holy Grail, no matter how impossible it sounded,” research lead Adrian Koh said in a release.

So far, Koh’s team has been able to create an artificial muscle that can bear 80 times its own weight and stretch to five times its original length. They could eventually be stretched to 10 times the original length.

The research team also expects robots could be self-charging. After a bot is charged for less than a minute and begins moving, the muscles could convert the movement into electrical energy, powering it from that point forward.

The team is working on a robotic arm that they expect to have ready in three to five years. Though it will be half the size and weight of a human arm, it will be strong enough to win an arm wrestling match against a human.