Engineering news
A team of Harvard University researchers has demonstrated ‘the world’s first’ autonomous, untethered, entirely soft robot.
According to the researchers the small 3D-printed robot — nicknamed the ‘octobot’ — is the first machine that can operate without the need to be tethered to an off-board system or rigged with hard electric power and control system components. Octopuses have long been a source of inspiration in soft robotics because of the creatures ability to perform feats of strength and dexterity with no internal skeleton.
Robert Wood, the Charles River professor of Engineering and Applied Sciences, and Jennifer A. Lewis, the Hansjorg Wyss professor of Biologically Inspired Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), led the research.
“One longstanding vision for the field of soft robotics has been to create robots that are entirely soft, but the struggle has always been in replacing rigid components like batteries and electronic controls with analogous soft systems and then putting it all together,” said Wood. “This research demonstrates that we can easily manufacture the key components of a simple, entirely soft robot, which lays the foundation for more complex designs.”
The research team was able to 3D print each of the functional components required within the soft robot body, including the fuel storage, power and actuation.
Harvard’s octobot is pneumatic-based, powered by gas under pressure. A reaction inside the robot transforms a small amount of liquid hydrogen peroxide fuel into a large amount of gas, which flows into the octobot’s arms and inflates them like balloons.
“Fuel sources for soft robots have always relied on some type of rigid components,” said Michael Wehner, a postdoctoral fellow in the Wood lab and co-first author of the paper. “The wonderful thing about hydrogen peroxide is that a simple reaction between the chemical and a catalyst — in this case platinum — allows us to replace rigid power sources.”
To control the reaction, the team used a microfluidic logic circuit based on work by co-author and chemist George Whitesides. The circuit, a soft analogue of a simple electronic oscillator, controls when hydrogen peroxide decomposes to gas in the octobot.
The entire system is simple to fabricate by combining three methods: soft lithography, molding, and 3D printing.
The simplicity of the assembly process should pave the way for more complex designs. Next, the Harvard team hopes to design an octobot that can crawl, swim, and interact with its environment.
“This research is a proof of concept,” said Ryan Truby, a graduate student in the Lewis lab and co-first author of the paper. “We hope that our approach for creating autonomous soft robots inspires roboticists, material scientists, and researchers focused on advanced manufacturing.”