Reporter Ellie Mackay looks into how researchers developed1 a printable magnetic material that can be programmed to jump, contract and catch a moving ball. Read the research.

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For decades, scientists have been working on materials that can change shape. Whether it’s bending, contracting or wriggling along, these kinds of ‘smart’ materials could be useful for robotics, engineering and medicine.

So far, many of these materials transform relatively slowly. Sometimes they need to be connected to a controller with wires or tubes, or they have a limited range of movements.

Now, scientists have developed a flexible smart material that is remotely activated, can move in multiple ways, and can transform quickly — changing its shape completely in less than a second.

This material can be 3D printed and scientists use magnets to change its shape.

The technique uses a soft silicone rubber embedded with tiny particles of iron. A magnetic field is used to magnetize the substance, creating a magnetic material that can be printed into any shape. And, the direction of the magnetic field can be changed during printing.

The result is a material with a non-uniform polarity, meaning each part of the structure can respond differently to a magnetic charge. Scientists added a red filter to film the movements.

The system is so precise that researchers can program a computer model to move in a certain way, print it out, and the same movement can be replicated exactly in the physical structure.

The team have already made shapes that can contract, deform, stop a ball, catch a ball, and even jump. But there are countless more possibilities. If it can be modelled, it can be made.

Because the magnetic field is applied remotely, these materials can be used in small, inaccessible places. In medicine this could be useful inside the body, for delivering drugs, or in surgery. Or in robotics, the complex shape changes could give soft robots flexible appendages.

In fact, along with existing smart materials, this speedy shape-changing technology has numerous potential uses in a range of industries — all with just the flip of a magnetic switch.