Artificial muscles developed at the University of Colorado are delicate enough to move a raspberry, strong enough to lift a gallon of water, and flexible enough to throw a ball.  Researchers hope that when incorporated into a prosthetic, they could closely mimic the actions of human muscles.

Human muscles can summon the strength to lift heavy objects, the sensitivity to grasp something delicate, and the energy to throw a ball. Now a new class of artificial muscles developed at the University of Colorado in Boulder can imitate all these motions, raising the possibility that a robot or human prosthetic could match -- perhaps even surpass -- its biological model.

The stretchy material highlighted in the yellow box is the HASEL actuator, or "artificial muscle" that moves this robotic arm.  The HASEL expands and contracts like a human muscle.

Courtesy University of Colorado

The artificial muscles are actuators, the parts of robots that create movement. Named HASELs, or "hydraulically amplified self-healing electrostatic" actuators, they are soft and stretchy. Electrodes placed in various positions create positive and negative charges, causing the HASELs to expand and contract. 

Tim Morrissey and Eric Acome, who helped develop the technology, tell Colorado Matters host Ryan Warner that HASELs have the potential to work faster and stronger than real human muscles. Articles detailing different designs appear in the journals Science and Science Robotics.

The artificial muscle, or "HASEL actuator" expands and contracts to lift a gallon of water.  The same technology can be modified for delicate touch instead of strength, to lift an egg or a raspberry, for example.

Courtesy University of Colorado