A team at Ulsan National Institute of Science and Technology (UNIST) in South Korea has created a new type of artificial muscle, a magnetic-composite actuator, that can lift about 4,000 times its own weight. The device weighs roughly 1.13 grams and has demonstrated the ability to lift up to 5 kilograms, reports Live Science.
What makes this development noteworthy is the resolution of a long-standing trade-off in artificial-muscle design: either high flexibility with low strength, or high strength with low flexibility. The new muscle uses a dual cross-linking composite: a covalently bonded chemical network and a reversible physical network. Magnetic microparticles (NdFeB) and a stiffness-tuning polymer matrix allow the muscle to switch between soft and stiff states, a key feature for robotic systems that need both compliance and load-bearing capability.
In contraction tests, the artificial muscle achieved an 86.4% strain, more than double that of human skeletal muscle, and a work density of about 1,150 kJ/m³, roughly 30 times of human muscle capability. Because it can stiffen when bearing heavy loads and soften when moving, the muscle becomes ideal for humanoid robots and wearable devices where motion and strength must be balanced.
Still, the accomplishment is at a proof-of-concept level. The researchers must now validate long-term durability, integration into full robotic systems, real-world control, and power-supply issues. For engineers working on robotics, automation, or wearable tech, this indicates a shift: actuators may no longer be bulky electric motors, but lightweight artificial muscles with human-or-better performance.
This magnetic-composite artificial muscle could redefine what robots can lift, how they move, and how human-machine systems are designed.