Podcast Episode
Australian Researchers Develop Liquid Metal Motor for Soft Robotics
January 20, 2026
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Researchers at the University of New South Wales have created a breakthrough motor that operates using a droplet of liquid metal instead of traditional rigid components, opening new possibilities for soft robotics, flexible electronics, and minimally invasive medical devices.
The device, called a liquid metal droplet rotary paddle motor, represents a fundamental departure from conventional motor design. Instead of relying on electromagnetic induction through coils and magnets, the motor generates motion through swirling flows inside a liquid metal droplet embedded in a salt solution and exposed to an electric field.
The copper paddle is carried along by the swirling liquid metal flows, creating rotation at speeds of up to 320 revolutions per minute. Doctor Priyank Kumar, a senior lecturer at UNSW who supervised the project, describes it as a completely new way to create motion without any traditional moving parts.
PhD student Richard Fuchs, who developed the motor, explained the elegance of the design by comparing it to a miniature waterwheel. Just as flowing water pushes the blades of a wheel, the swirling liquid metal pushes the copper paddles to create rotational motion.
The research represents a conceptual departure from previous liquid metal actuator designs, which were limited in rotational speed due to suboptimal extraction of mechanical motion from the liquid metal. The new design addresses these limitations through improved flow dynamics and torque transfer mechanisms.
Professor Kourosh Kalantar-Zadeh from the University of Sydney, a collaborator on the project, envisions tiny robots that can move through narrow, irregular spaces inside the human body. These devices would be powered by motors that are soft and flexible rather than hard and fragile, making them suitable for navigating blood vessels, the digestive system, or other delicate internal environments without causing tissue damage.
Beyond robotics, the researchers identified potential applications in microfluidic devices and biomedical implants, where compact, self-contained motion is required in delicate or confined environments. The motor's simplicity and flexibility make it an attractive option for next generation medical devices that require precise, controlled movement in sensitive biological contexts.
Professor Kalantar-Zadeh acknowledged that while the current design remains rudimentary, the technology demonstrates significant potential when developed further. The proof of concept has been established, showing that liquid metal motors can generate usable rotational motion without rigid components.
Future development will focus on refining the motor's performance, improving efficiency, scaling the technology for different applications, and integrating it into practical robotic and medical systems. Researchers will also explore different liquid metal compositions, electrolyte solutions, and paddle designs to optimize performance for specific use cases.
The motor represents a shift in thinking about how mechanical motion can be generated and controlled. By eliminating rigid components and embracing the fluid dynamics of liquid metals, researchers have opened a new pathway for creating machines that can operate in environments previously inaccessible to conventional motors.
As the technology matures and moves from laboratory demonstrations to practical applications, it could enable a new generation of medical devices, soft robots, and flexible machines capable of navigating complex, confined, or delicate environments that rigid technology cannot safely access.
How the Technology Works
The motor operates by harnessing electrochemical and surface tension driven fluid flows. When an electric field is applied across the liquid metal droplet, it generates interfacial tension gradients and electrohydrodynamic flows along the droplet surface. These forces drive internal vortices within the liquid metal that apply torque to a small copper paddle inserted into the droplet.The copper paddle is carried along by the swirling liquid metal flows, creating rotation at speeds of up to 320 revolutions per minute. Doctor Priyank Kumar, a senior lecturer at UNSW who supervised the project, describes it as a completely new way to create motion without any traditional moving parts.
PhD student Richard Fuchs, who developed the motor, explained the elegance of the design by comparing it to a miniature waterwheel. Just as flowing water pushes the blades of a wheel, the swirling liquid metal pushes the copper paddles to create rotational motion.
Advantages Over Conventional Motors
The liquid metal motor's soft, adaptable nature makes it particularly promising for applications where rigid components are impractical or unsuitable. Traditional motors excel in many contexts, but their rigid structure limits their use in environments requiring flexibility, compactness, or the ability to navigate confined spaces.The research represents a conceptual departure from previous liquid metal actuator designs, which were limited in rotational speed due to suboptimal extraction of mechanical motion from the liquid metal. The new design addresses these limitations through improved flow dynamics and torque transfer mechanisms.
Medical and Robotic Applications
Soft robotics stands to benefit most from this technology. These machines often need to bend, stretch, or squeeze into tight, irregular spaces where conventional rigid robots cannot operate effectively.Professor Kourosh Kalantar-Zadeh from the University of Sydney, a collaborator on the project, envisions tiny robots that can move through narrow, irregular spaces inside the human body. These devices would be powered by motors that are soft and flexible rather than hard and fragile, making them suitable for navigating blood vessels, the digestive system, or other delicate internal environments without causing tissue damage.
Beyond robotics, the researchers identified potential applications in microfluidic devices and biomedical implants, where compact, self-contained motion is required in delicate or confined environments. The motor's simplicity and flexibility make it an attractive option for next generation medical devices that require precise, controlled movement in sensitive biological contexts.
Current Status and Future Development
The research was published in the journal npj Flexible Electronics, marking an important milestone in the field of soft robotics and flexible electronics. However, the technology remains in early development stages.Professor Kalantar-Zadeh acknowledged that while the current design remains rudimentary, the technology demonstrates significant potential when developed further. The proof of concept has been established, showing that liquid metal motors can generate usable rotational motion without rigid components.
Future development will focus on refining the motor's performance, improving efficiency, scaling the technology for different applications, and integrating it into practical robotic and medical systems. Researchers will also explore different liquid metal compositions, electrolyte solutions, and paddle designs to optimize performance for specific use cases.
Broader Implications
This breakthrough adds to the growing field of liquid metal technologies, which have shown promise in various applications including flexible electronics, wearable devices, and adaptive materials. The low toxicity of certain liquid metals makes them particularly suitable for biomedical applications and devices with direct human interaction.The motor represents a shift in thinking about how mechanical motion can be generated and controlled. By eliminating rigid components and embracing the fluid dynamics of liquid metals, researchers have opened a new pathway for creating machines that can operate in environments previously inaccessible to conventional motors.
As the technology matures and moves from laboratory demonstrations to practical applications, it could enable a new generation of medical devices, soft robots, and flexible machines capable of navigating complex, confined, or delicate environments that rigid technology cannot safely access.
Published January 20, 2026 at 1:34am
