Octobot, autonomous, entirely soft robot

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Powered by a chemical reaction controlled by microfluidics, 3D-printed, the first autonomous, entirely soft robot, has no electronics.

A team of Harvard University researchers with expertise in 3-D printing, mechanical engineering, and microfluidics has demonstrated the first autonomous, untethered, entirely soft robot. This small, 3-D-printed robot — nicknamed the “octobot” — could pave the way for a new generation of such machines.

Soft robotics could help revolutionize how humans interact with machines. But researchers have struggled to build entirely compliant robots. Electric power and control systems — such as batteries and circuit boards — are rigid, and until now soft-bodied robots have been either tethered to an off-board system or rigged with hard components.

octobot first autonomous soft robot

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. Lewis and Wood are also core faculty members of the Wyss Institute for Biologically Inspired Engineering at Harvard University.

“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.”

“Through our hybrid assembly approach, we were able to 3-D 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.”

Powered by hydrogen peroxide

 

octobot-990x546

octobot-structure

Octobot structure. A system of check valves and switch valves within the soft controller regulates fluid flow into and through the system. The reaction chambers convert the hydrogen peroxide to oxygen, which then inflates the bot arms. The 500-micrometers-high “VERITAS” letters are patterned into the soft controller as an indication of scale. (credit: Michael Wehner et al./Nature)

octobot-control-logic

Octopuses have long been a source of inspiration in soft robotics. These curious creatures can perform incredible feats of strength and dexterity with no internal skeleton.

Harvard’s octobot is pneumatic-based, and so is powered by gas under pressure. A reaction inside the bot transforms a small amount of liquid fuel (hydrogen peroxide) into a large amount of gas, which flows into the octobot’s arms and inflates them like balloons.

Octobot mechanical schematic (top) and electronic analogue (bottom). Check valves, fuel tanks, oscillator, reaction chambers, actuators and vent orifices are analogous to diodes, supply capacitors, electrical oscillator, amplifiers, capacitors and pull-down resistors, respectively. (credit: Michael Wehner at al./Nature)

Octobot mechanical schematic (top) and electronic analogue (bottom). Check valves, fuel tanks, oscillator, reaction chambers, actuators and vent orifices are analogous to diodes, supply capacitors, electrical oscillator, amplifiers, capacitors and pull-down resistors, respectively. (credit: Michael Wehner at al./Nature)

 

“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 pioneering work by co-author and chemist George Whitesides, the Woodford L. and Ann A. Flowers University Professor and a core faculty member of the Wyss. The circuit, a soft analog 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 fabrication methods — soft lithography, molding, and 3-D 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 simplicity of the assembly process paves the way for designs of greater complexity. 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,” Truby said. “We hope that our approach for creating autonomous soft robots inspires roboticists, material scientists, and researchers focused on advanced manufacturing.”

More info:

Original article on Harvard Gazette.

An integrated design and fabrication strategy for entirely soft, autonomous robots.

Harvard School of Engineering and Applied Sciences.

Wyss Institute for Biologically Inspired Engineering.

Kurzweil News.

FiveWordsForTheFuture - Oct 2, 2016 | 3D printing, Robotics
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