Robots do not always need conventional electric motors to move. Researchers at ETH Zurich have developed tiny biohybrid robotic actuators that combine living muscle tissue with a soft artificial scaffold, enabling small devices to jump, swim, walk and grasp objects. The research offers a new approach to designing robotic movement by engineering biological tissue and its supporting structure as one integrated system.
Published in Nature Communications and highlighted by ETH Zurich on October 22, 2026, the work addresses a major challenge in biohybrid robotics: cultured muscle can contract, but translating that contraction into useful movement has often been difficult. The researchers report that their redesigned actuators achieve a range of motion up to 11 times greater than earlier systems using a comparable amount of muscle tissue.
How Living Muscle Powers the Tiny Robots
The actuators combine lab-grown skeletal muscle tissue derived from mouse muscle cells with a soft hydrogel scaffold. Hydrogels are water-rich materials that can deform under force, making them useful for constructing flexible structures. When the living muscle contracts, the scaffold helps translate that movement into a larger, controlled change in shape.
Instead of designing the artificial structure first and fitting muscle tissue into it afterward, the ETH Zurich team co-designed both components using computer simulations. An algorithm explored different muscle arrangements and scaffold properties to identify configurations that could produce greater movement from the available muscle tissue. The resulting actuators are approximately 1.5 centimetres long.
Computer Design Makes Muscle Movement More Effective
The key innovation is not simply the use of living muscle, but how the muscle and its supporting material work together. The researchers designed fine grooves into the scaffold to help the tissue anchor securely and align its muscle fibres. This connection reduces the loss of force as the muscle contracts and transfers movement to the artificial structure.
The team manufactured the scaffolds using a light-based 3D-printing technique known as xolography. According to ETH Zurich, producing a scaffold takes about one minute. The researchers then tested the actuators, used experimental observations to refine their computer models, and repeated the design process to improve performance.
Jumping, Swimming and Grasping at a Tiny Scale
The resulting devices can perform several types of movement, including jumping, swimming, walking across a surface and grasping objects. In one demonstration, an actuator lifted itself approximately five millimetres in a single contraction—around one-third of its body length. A walking version moved at 6.2 millimetres per second, which the researchers report as a particularly high speed relative to body length for a walking biohybrid robot.
These results demonstrate how carefully designed biological and artificial components can produce visible movement at a very small scale. The robots are not miniature versions of industrial machines, and the research does not establish that they can replace conventional motors. Instead, it explores a different way to create motion using the force and flexibility of living tissue.
Why Biohybrid Robotics Could Matter
Living muscle has properties that are difficult to reproduce with rigid mechanical components. It can contract, change shape and generate force within a compact structure. Combining those characteristics with engineered soft materials could eventually help researchers develop robots that bend, adapt and interact with delicate objects in ways that are difficult for traditional mechanisms.
Potential long-term research directions include soft robotic manipulators, microscale devices and specialised machines designed to work in environments where flexibility matters. However, these are possible future applications rather than capabilities demonstrated by the current prototypes. Additional work would be required to establish whether biohybrid systems can be made reliable, controllable and practical outside laboratory experiments.
The Biggest Challenge: Keeping the Tissue Alive
Despite the promising movements, the technology remains at an early research stage. The living muscle tissue currently depends on a nutrient solution to remain viable. Larger biohybrid systems would need a way to deliver oxygen and nutrients to their tissue while removing waste products, potentially requiring an artificial vascular system.
Researchers must also address variability in living tissue. Unlike mass-produced motors, cultured muscle can develop differently from one sample to another, which may affect strength, movement and consistency. Improving tissue maturation, control and repeatability will be essential before these actuators can be incorporated into practical robotic systems.
A Different Future for Soft Robots
The ETH Zurich research suggests that future robotic movement could draw more directly on biological mechanisms rather than relying exclusively on electric motors, gears and rigid joints. By designing living muscle and its scaffold together, engineers may gain greater control over how small structures deform and move.
For now, the achievement is a laboratory demonstration, not a ready-to-deploy robotic product. The next steps involve improving tissue longevity, making performance more consistent and determining which tasks benefit most from living actuators. If those challenges can be overcome, biohybrid robotics could become a useful complement to conventional robotic systems, particularly where soft, adaptable movement is valuable.
