South Korean Scientists Develop Artificial Muscles Up to 30 Times More Powerful

South Korean scientists at KAIST and UNIST develop artificial muscles with up to 30 times human muscle work density, advancing robotics and prosthetics.

South Korea: Scientists in South Korea are making significant progress in artificial muscle technology, developing advanced materials capable of generating mechanical work far beyond the performance of natural human muscles.

Researchers at the Korea Advanced Institute of Science and Technology (KAIST) and the Ulsan National Institute of Science and Technology (UNIST) have demonstrated two separate breakthroughs that could reshape the future of robotics, wearable technologies, medical rehabilitation and artificial limbs.

The developments, reported in 2022 and 2025, demonstrate how engineered materials can reproduce some of the movement and strength characteristics of biological muscles while offering additional capabilities.

KAIST Develops Graphene-Based Artificial Muscle

One of the major breakthroughs came from a research team led by Professor Sang Ouk Kim at KAIST.

The researchers developed artificial muscle fibres by combining graphene, an advanced carbon-based material, with liquid crystal elastomers. The resulting material, known as a graphene–liquid crystal elastomer composite, can contract and expand in a way that resembles natural muscle movement.

According to the research published in Nature Nanotechnology, the artificial muscle achieved a work capacity of approximately 17 times that of natural human muscle and a power density around six times higher.

The researchers also demonstrated that a single artificial muscle fibre could lift a one-kilogram dumbbell. They developed an artificial inchworm that moved faster than its biological counterpart.

The technology can also respond to near-infrared light, allowing researchers to control its movement remotely through light-based stimulation.

These properties make the material particularly interesting for developing flexible robotic systems and wearable mechanical devices.

UNIST Develops Artificial Muscle That Can Stretch Like Rubber and Become Rigid Like Steel

A second major development was announced in September 2025 by researchers at UNIST, led by Professor Hoon Eui Jeong from the Department of Mechanical Engineering.

Unlike conventional artificial muscles, which often struggle to combine flexibility with strength, the new material can dynamically change its stiffness depending on the task.

When flexibility is required, the material can stretch significantly. When it needs to support heavy loads, it becomes rigid and stronger.

The experimental artificial muscle weighs just 1.25 grams but can support a load of approximately five kilograms in its rigid state. This represents roughly 4,000 times its own weight.

Other impressive experimental results include:

• 30 times higher work density: Approximately 1,150 kJ/m³ compared with human muscle.

• 86.4% actuation strain: More than twice the approximately 40% associated with human muscle.

• 12 times stretchability: The material can stretch up to 12 times its original length.

• Five-kilogram load capacity: A 1.25-gram artificial muscle can support approximately five kilograms when rigid.

The research was published in Advanced Functional Materials in September 2025.

The ability to switch between softness and stiffness could help solve one of the major challenges in soft robotics: creating machines that are both flexible enough to interact safely with people and strong enough to perform demanding physical tasks.

These developments could eventually support several important applications.

1. Advanced Robotics

Robots equipped with artificial muscles could perform more natural movements, handle delicate objects and operate in environments designed for humans.

2. Wearable Exoskeletons

Artificial muscles could help develop lightweight wearable systems that assist people with lifting, walking and physically demanding activities.

3. Medical Rehabilitation

Future rehabilitation devices could help patients regain movement and support physical therapy following injuries or neurological conditions.

4. Next-Generation Prosthetics

Artificial muscle technology could contribute to prosthetic arms and legs with more natural movement, flexibility and strength.

5. Human-Robot Interaction

Soft robotic materials could make robots safer when working alongside people, particularly in healthcare, manufacturing and assistance-related applications.

Are Artificial Muscles Ready to Replace Human Muscles?

Despite the impressive laboratory results, these technologies are not yet ready to replace natural human muscles or become widely available in commercial robots.

Researchers still need to address challenges involving energy efficiency, durability, precise control, manufacturing costs and long-term performance.

The two South Korean developments also use different materials and experimental approaches, so their performance figures should not be treated as a direct head-to-head comparison.

Nevertheless, they represent important progress towards a future in which robots could move more naturally, wearable devices could provide greater physical assistance and artificial limbs could become increasingly sophisticated.

South Korea's research demonstrates how advanced materials science could transform the next generation of robotics and human-assistance technologies.

By News National Editorial Team

Sources and References

1. Nature Nanotechnology – Human-muscle-inspired single fibre actuator with reversible percolation (KAIST research).

2. KAIST – Human muscle-inspired Hercules artificial muscle fibre.

3. UNIST – Official artificial muscle research announcement, September 2025.

4. Advanced Functional Materials – Scientific research paper, 2025.