A team of researchers in South Korea has developed an artificial muscle capable of lifting 4,000 times its own weight, marking a significant advancement in robotics and soft materials technology. The innovation, detailed in a study published September 7 in the journal Advanced Functional Materials, could pave the way for more versatile humanoid robots, wearable devices, and intuitive human-machine interfaces.
The breakthrough lies in the muscle’s unique ability to be both flexible and strong—qualities that have long been difficult to combine in artificial systems. Previous artificial muscles often faced a trade-off: they were either highly stretchable but weak, or strong but rigid. This new composite material overcomes that limitation by integrating two distinct cross-linking mechanisms and magnetic microparticles, allowing precise control over its stiffness and movement.
The artificial muscle, weighing just 1.13 grams, can support up to 5 kilograms—roughly 4,400 times its own weight. It also achieves a strain of 86.4%, more than double that of human muscle, and a work density of 1,150 kilojoules per meter cubed, 30 times higher than human tissue. These capabilities were measured using a uniaxial tensile test, which assesses how materials respond to pulling forces.
The dual cross-linking architecture—combining covalent chemical bonds with reversible physical interactions—enhances durability, while magnetic microparticles on the surface can be controlled via a colorless liquid, enabling dynamic adjustments in stiffness. This design allows the muscle to mimic human-like movement while maintaining superior strength and adaptability.
“This research overcomes the fundamental limitation where traditional artificial muscles are either highly stretchable but weak or strong but stiff,” explained lead researcher Hoon Eui Jeong, a mechanical engineering professor at the Ulsan National Institute of Science and Technology. “Our composite material can do both, opening the door to more versatile soft robots and wearable devices.”
The implications of this breakthrough extend beyond robotics. By enabling more intuitive human-machine interactions and adaptable wearable technology, the artificial muscle could transform industries ranging from healthcare to manufacturing, bringing us closer to seamless integration between humans and machines.
This breakthrough represents a major leap forward in artificial muscle technology, addressing a long-standing challenge in robotics. By combining strength and flexibility in a single material, researchers have created a versatile tool with applications far beyond weightlifting
