The first autonomous, untethered, entirely soft robot was created by a team of Harvard University. The “octobot” is shaped like an octopus and was made with 3D printing, lithography, and molding. The new creation is a milestone for soft machines, eliminating rigid system from robots for good.

Harvard’s new discovery is nicknamed “octobot” and is the prove that robots can be built with soft elements, including batteries and circuits boards. Electric power and control systems have been a challenge for soft robotic. The most similar to a complete soft robot was a soft-bodied machine with hard internal elements.

Harvard’s new discovery is nicknamed "octobot" and is the prove that robots can be built with soft elements. Photo credit: R Truby / M Wehner / L Sanders / Harvard University / BBC
Harvard’s new discovery is nicknamed “octobot” and is the prove that robots can be built with soft elements. Photo credit: R Truby / M Wehner / L Sanders / Harvard University / BBC

The octobot is based on pneumatic mechanisms and powered by gas under pressure, meaning that a chemical reaction controls the robot. Inside the soft machine hydrogen peroxide and a catalyst- in the case of the octobot platinum- replace rigid power sources by chemically interacting. Hydrogen peroxide is the fuel and when is in contact with the platinum a significant amount of gas flows through the octopus-shaped robot and inflates its arms.

The reaction must be contained, and the team came with the idea of using a microfluidic logic circuit based on George Whitesides research. Whitesides pioneering work inspired a soft analog circuit made of a simple electronic oscillator that controls the hydrogen peroxide. George Whitesides is a co-author on the paper and a chemist, the Woodford L. and Ann A. Flowers University Professor and core faculty member of the Wyss.

Once the gas is created, it is pumped into the circuit by a little cell filled with the fuel and the reaction happens when the hydrogen peroxide makes contact with platinum particles that were left in the 3D printed parts. The circuit decides when the fuel decomposes to gas in the soft robot.

Jennifer A. Lewis, one of the leading authors and Hansjorg Wyss Professor of Biologically Inspired Engineering at Harvard John A. Paulson School of Engineering and Applied Science (SEAS), stated that the team had a hybrid assembly approach creating the soft robot. Printing 3D functional parts and combining them with lithography and molding is a demonstration of the team’s integrated design and additive fabrication strategy to embed autonomous functionality.

Co-first author Ryan Truby says the entire system of the octobot is easy to make, and it is also fast, making it possible a quick, significant production.

Why does a soft robot is trying to copy octopus and not another animal?

Despite not having an internal skeleton, octopuses, are incredibly strong and bright, and their structure has been a source of reference in soft robotics.

But according to Robert Wood, the Charles River Professor of Engineering and Applied Sciences, to create reliable soft robots have been a struggle because of rigid components. And once they discovered how to fabricate those hard elements into soft ones, the other obstacle was to put them all together.

What makes unique this soft robot is that the Harvard team managed to control the octobot from the inside instead of from the outside. The machine does not rely on external power sources.

The octopus-shaped robot is pre-programed and allows the soft mechanism to move its tentacles.This is the first functioning prototype and its movements are slow and cannot make the robot walk. It only alternates its eight legs when they are going up and down: four feet are up, and the other four are down. It is important to remind that the octobot is still a milestone in soft robotics. It has no hardware.

Soft robots: they could do what rigid bodies cannot

From the octobot, scientists will continue to work to create soft robots that could access difficult surgical locations. The soft structure could be used to reach challenging obstacles for rescuers or to research where rigid robots cannot. According to Truby, another benefit is that humans can interact with this kind of robots safely.

The next projects for the Harvard team are to make the octobot capable of crawling, swimming, and interact with its environment. Mr. Truby hopes that their creations would inspire roboticist, material scientists, and researchers in the advanced manufacturing area.

The BBC reports that Jonathan Rossiter, who runs the soft robotics group at the Bristol Robotics Lab, stated the Harvard team had achieved a unique machine. He added that the robot was made in a way that other engineers can look at it and use its mechanisms to build one themselves with may be better fuel systems or better control systems.

The octobot is definitely a way to bring people together to accomplish something great. The new prototypes could change the robotics race.

The research was published in the Journal Nature and was supported by the National Science Foundation through the Materials Research Science and Engineering Center at Harvard and by the Wyss Institute.  

Source: Harvard