Real-life transformer robots, that can fold themselves into shape from flat in four minutes and then crawl and turn, have been built by researchers in the United States.

Scientists say the machines could be used for a variety of purposes, including accessing confined spaces to carry out search and rescue missions.

The robots use patterns drawn from the Japanese art of paper folding, origami, as well as the concept of self-assembly found throughout nature in their engineering and design.

According to research, published in the Science journal, the idea of the self-organisation of flat materials into complex scalable strong 3D shapes is not new in engineering.

However, until now such research has not produced machines that can fold themselves and then function without assistance from people.

But this work saw the scientists in Massachusetts produce a self-folding robot that can crawl and turn, built with easy to find materials including memory polymer that contracts at 100C, and self-folding hinges that are triggered by heat generating circuits.

The researchers used 3D origami design software to produce crease patterns in the polymer.

Members of the same team, which studied a specific type of zigzag origami fold, produced light but ultra strong materials whose properties like stiffness and strength could be altered for use in different ways.