Is it possible to build origami robots

Origami Transformers crawl off

Cambridge (USA) - It makes you sit up and take notice when you hear about completely independent robots. Even more so, when these robots fold themselves up from a thin sheet of plastic and go into action without further guidance. You don't just think of Terminator or the Transformers - the military is also becoming more and more interested in autonomous drones or combat robots. The little robots that American researchers have now designed are, however, very peaceful and, moreover, downright artistically valuable.

Because their design follows the principles of origami, an ancient Japanese art of folding. Masters experienced in origami can conjure up amazing figures out of a sheet of paper without scissors and glue, just with skillful folding and bending. This principle could also be used to produce technical objects, thought a research group led by Robert Wood from Harvard University in Cambridge. "And we were not only inspired by origami techniques," says Wood. “There are also many examples in nature, such as the unfolding of leaves or insect wings.” The scientists published their research in the journal “Science”.

The robot consists of nothing but a thin sheet of special plastic that was glued with paper, as well as two motors and two batteries and a small control unit. The researchers had applied thin cables to the plastic through which the control unit could send electricity and thereby warm up. The plastic then began to deform at a temperature of around 100 degrees Celsius. Thanks to clever geometry and precise control, the folding robots then gradually took on their final shape. After just four minutes, the plastic hinges were cold and hardened again - and for the first time such a robot could fold itself up and crawl on its own without any human help.

At first it was simply a matter of showing how the new construction principle can actually work. The folding robot cannot yet do much more than crawl forward at a good five centimeters per second or turn slowly. "By folding you can do without the nuts and bolts that you usually need for robots or other electromechanical devices," says Wood. “This means that the electronics can be integrated into the device while it is still flat.” This means that such robots can be manufactured quickly and cheaply in large numbers. There are many possible fields of application: for example, in disasters, where they can be brought to the site to save space and help them search for buried subjects - or with miniature robots that are so small that they are difficult to build by hand. "You could also imagine a group of dozens of robot satellites that can be brought compactly into space and then assemble themselves there, so to speak," says Sam Felton, first author of the study.

Of the three prototypes that the researchers built, only one worked as planned. With the other two, however, it was only a single one of two dozen hinges that did not quite get into the right position. The energy consumption for the folding process is also still relatively high: a robot drew around ten times more power from the battery than a light bulb. At the end of the folding process, one of the two batteries was already empty.

For example, better materials that can be shaped at lower temperatures could save a lot of energy here. “There are a lot of things that we can improve on this prototype,” says Felton. There they come again, the thoughts of the Transformers.

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