Engineers have shown a new way to make solid blocks that can change their mechanical properties, which are traits like how stiff or flexible something is. These blocks act like Lego pieces and could help create robots that adjust themselves quickly. In tests, a beam made from these blocks helped a robotic fish swim in different ways using the same motor. The idea is to make tiny versions for tasks like checking blood vessels or forming stents, which are tubes that hold blood vessels open.
The blocks use a mix of gallium and iron, metals that can be solid or liquid at room temperature. Heat from electricity turns chosen parts liquid, like saving data on a computer. This lets the material act stiff or soft without changing shape.
Demonstrating the concept in action
In flat sheets, the material copies the feel of plastics or rubbers by adjusting stiffness and damping, which is how it absorbs shocks. In three dimensions, each block looks like a small cube with 27 tiny cells inside. Blocks stick together and can be reprogrammed by melting patterns with heat. Cooling to zero degrees Celsius resets everything to solid for new setups.
In one example, ten blocks formed a tail for a robotic fish. Different liquid patterns made the tail bend uniquely, changing how the fish moved. Future plans include using other metals to work at body temperatures, shrinking the tech for tight spaces like veins or electronics.
“Our goal is to eventually construct larger systems using the composite materials,” said research leader Xiaoyue Ni in a press release. “We want to build flexible, programmable materials for robotics that can enable them to perform a wide variety of tasks in a wide variety of environments.”
The engineers have described the methods and results of this study in a paper published in Science Advances.