Engineers have developed a tiny liquid-metal pump that could help make future soft robots, wearable devices, and medical technologies smaller, lighter, and more flexible.
The new invention is so compact that it is about the size of a pea, yet it can power robotic movements using less than 0.1 volts of electricity.
The technology was developed by researchers at the University of Bristol and described in the journal Nature Communications.
The team believes it could eventually be used in applications ranging from robotic clothing and smart medical devices to virtual reality systems and environmental monitoring tools.
To demonstrate its capabilities, the researchers built several working prototypes.
These included robotic butterfly wings that flap like a real insect’s wings, a bracelet that changes color, and a wearable device that creates realistic touch sensations by gently squeezing a user’s fingertip and wrist.
One of the biggest challenges facing soft robotics today is the need for bulky equipment. Many soft robots rely on large compressors or rigid pumps to move fluids and generate motion. These systems can be heavy, inflexible, and difficult to carry around.
The new device offers a different approach. Called the Liquid-Metal Magnetohydrodynamic Actuation (LIMA) pump, it weighs only about 0.2 grams and uses a tiny droplet of liquid metal to generate movement.
The pump works through a simple but powerful physical principle. When an electric current passes through the liquid metal while it is exposed to a magnetic field, a force known as the Lorentz force is created. This force causes the droplet to move back and forth. As it moves, it pushes the surrounding fluid, creating a pumping action that can power soft robotic systems.
According to lead researcher Saba Firouznia from the University of Bristol Soft Robotics Lab, the pump takes advantage of several unique properties of liquid metal. It conducts electricity extremely well, can easily change shape, has high surface tension, and moves with very little resistance. These features allow the pump to operate at extremely low voltages while still producing enough pressure and fluid flow to drive robotic movement.
The researchers say the technology does more than simply move fluid. It can also transfer energy, chemical signals, and information through soft fluid-filled networks. This opens the door to multifunctional robotic systems that are more autonomous and adaptable than current designs.
Professor Jonathan Rossiter, co-author of the study and head of Bristol’s Soft Robotics Research Group, described the pump as a compact “heart” for future robotic systems. By combining pumping, communication, and energy transfer into a single device, it could simplify the design of many robotic technologies.
Although the invention is still in the research stage, the team is already exploring practical applications. Potential future uses include smart bandages that respond to injuries, advanced wearable devices, robotic clothing, tiny medical tools, and even edible robots that can safely operate inside the human body.
The researchers believe this tiny liquid-metal pump could become a key building block for the next generation of soft, portable, and highly adaptable robotic systems.
