Aug 25 2016
Image Credit: Lori Sanders/Harvard University
Harvard University researchers who specialize in mechanical engineering, 3D printing, and microfluidics have showcased the first independent, untethered, completely soft robot.
It is a small, 3D-printed robot, called the octobot. It could lead to the development of a new generation of fully soft, independent machines.
Introducing the Octobot
Video Credit: Harvard University/Youtube.com
It is very likely that soft robotics will transform the way humans work with machines, however it has been a hard task for researchers to build completely compliant robots.
Electric power and control units, such as batteries and circuit boards, are not flexible, and until now soft-bodied robots have been either engineered with hard components or tethered to an off-board system.
The research was led by 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).
Lewis and Wood are also core faculty members of the Wyss Institute for Biologically Inspired Engineering at Harvard University.
One long-standing 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. 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.
Robert Wood, Professor, Harvard University SEAS
The research is illustrated in the Nature journal.
“Through our hybrid assembly approach, we were able to 3D print each of the functional components required within the soft robot body, including the fuel storage, power and actuation, in a rapid manner,” said Lewis. “The octobot is a simple embodiment designed to demonstrate our integrated design and additive fabrication strategy for embedding autonomous functionality.”
Soft robotics has been inspired by octopuses. Octopuses with no internal skeleton are capable of performing extraordinary feats of dexterity and strength.
The octobot created by the Harvard researchers is pneumatic-based - powered by gas under pressure. A reaction within the bot converts a small quantity of liquid fuel - hydrogen peroxide - into a large quantity of gas, which flows into the arms of the octobot and causes them to inflate like a balloon.
Fuel sources for soft robots have always relied on some type of rigid components. 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.
Michael Wehner, Postdoctoral Fellow, Harvard University SEAS
To manage the reaction, the team used a microfluidic logic circuit based on revolutionary work by co-author and chemist George Whitesides, the Woodford L. and Ann A. Flowers University Professor and core faculty member of the Wyss. The circuit is a soft analog of a basic electronic oscillator, and it controls when the hydrogen peroxide decomposes to gas in the octobot.
“The entire system is simple to fabricate, by combining three fabrication methods — soft lithography, molding and 3D printing — we can quickly manufacture these devices,” said Ryan Truby, a graduate student in the Lewis lab and co-first author of the paper.
The assembly process is quite simple and could enable the development of more complex designs. Going forward, the Harvard team plans to design an octobot that is capable of swimming, crawling, and interacting with its environment.
This research is a proof of concept. We hope that our approach for creating autonomous soft robots inspires roboticists, material scientists and researchers focused on advanced manufacturing,
Ryan Truby, Graduate Student, Harvard University SEAS
Daniel Fitzgerald of the Wyss Institute and Bobak Mosadegh, of Cornell University co-authored the paper. The research was supported by the National Science Foundation through the Materials Research Science and Engineering Center at Harvard and by the Wyss Institute.
Powering the Octobot: A chemical reaction
Video Credit: Harvard University/Youtube.com