The world's first soft autonomous robot moves on hydrogen peroxide

Robot Octobot. Photo: Institute of Bionic Engineering. Wissa

In recent years, scientists have been actively experimenting with soft electronics. Soft elastic items are generally more comfortable in life than hard metal and plastic. This applies to almost any objects. Electronics and robots are no exception. Therefore, it is logical to assume that the future is precisely for soft robots. Such elastic and resilient cybernetic creatures will be put on the head and stretched on the body, taken inside. They are not afraid of water and corrosion, they can slide or slide on inclined surfaces. They are not afraid of damage, deformation, etc. - they have many advantages over rigid structures [one] [2] . And they are so nice to stroke and pat on the elastic calf.

Completely soft mechanisms without a single solid detail were created before, but they were quite primitive robots, like a caterpillar . Now engineers from Harvard University have succeeded in showing the world's first fully autonomous independent robot Octobot in the image of a cute octopus, which moves due to the chemical reaction of restoring hydrogen peroxide (H ₂ O ₂ ).


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The authors of the invention of the Harvard Institute of Bionic Engineering. Wissa believe that such robots are already suitable for mass production using a simple process technology, including soft batteries and soft electronic circuits. This simple design can be a key component for creating more complex soft robots of the future.

Most of the Octobot parts are printed on a 3D printer, and then electrically conductive circuits and gas vessels are inlaid into its body using lithography.


Gas vessels are pressed by the method of lithography. Illustration: Institute of Bionic Engineering. Wissa


The technical process of making Octobot. Photo: Institute of Bionic Engineering. Wissa

The robot moves due to the gas released from hydrogen peroxide - fuel. The fluid moves through the body, and gas swells the limbs. Scientists have designed a cunning network of microvessels to move fluid throughout the body. This network of vessels is designed in such a way that, when swelling of some limb fragments, others are blown away, in a predetermined sequence, which allows the robot to move. The algorithm of swelling and blowing is implemented in a simple logical scheme.


The logic circuit of the robot. Illustration: Institute of Bionic Engineering. Wissa

The robot works on 50% hydrogen peroxide solution. For comparison, in most household products a solution of 5% is usually used.

The robot can move the limbs independently, without external control, therefore it is considered autonomous. The change in pressure in the limbs is the main way of movement for all soft robots, and now scientists have found for the first time a way to start this process completely offline.

Hydrogen peroxide instantaneously disintegrates into water and gaseous oxygen when in contact with platinum on the walls of the channels - in those areas where the extremities swell. Chemical reaction with hydrogen peroxide concentration of 50% and 90% is shown in the video.



Gas takes up to 160 times more volume than liquid. Due to this, Octobot moves limbs. Now he can move tentacles for 4 to 8 minutes on one milliliter of hydrogen peroxide solution.

The network of microvessels was designed with the participation of the famous chemist George Whitesides , the winner of many prestigious awards (according to Wikipedia, this is the 1st chemist in the world from 1992 to 2002, and the 1st in the world in quoting chemists from living chemists in 2011 year, Hirsch index = 169). He also works at the Institute of Bionic Engineering. Wissa.


Octobot microvessel network under the microscope. Illustration: Institute of Bionic Engineering. Wissa

The design looks promising for some areas of the use of robots, including inside the human body. Of course, a physicochemical autonomous system itself is simpler than the usual autonomous computer-controlled robots, but this is the first such design in the world, so to speak, a proof-of-concept, that is, proof of the viability of an idea. The octopus form factor was chosen arbitrarily: “We decided that the octopus just looks cool,” says Michael Wehner, lead author of the scientific work. “We thought that such a cool octopus would help attract people to soft robotics.”

In the next version, developers want to teach Octobot to swim and interact with surrounding objects. To do this, it is necessary to complicate its logical scheme and, possibly, complicate the network of microvessels.

Now this octopus looks ridiculous and useless, but it gives an opportunity to imagine a future in which soft autonomous robots will become real.

The scientific work "Integrated design and production strategy for fully soft, autonomous robots" was published on August 24, 2016 in the journal Nature (doi: 10.1038 / nature19100, pdf ).

Literature

<sup>[1] Rus, D. & Tolley, MT Design, fabrication and control of soft robots. Nature 521, 467–475 (2015). Back to article

[2] Wang, L. & Iida, F. Deformation in soft-matter robotics: a categorization and quantitative characterization. IEEE Robot. Autom. Mag. 22, 125–139 (2015). Back to article</sup>