The 1st Autonomous, entirely Soft Robot

The octobot is powered by a chemical reaction and controlled with a soft logic board. 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 a balloon. The team used a microfluidic logic circuit, a soft analog of a simple electronic oscillator, to control when hydrogen peroxide decomposes to gas in the octobot. Credit: Lori Sanders

Powered by a chemical reaction controlled by microfluidics, 3D-printed ‘octobot’ has no electronics. A team of Harvard University researchers with expertise in 3D printing, mechanical engineering, and microfluidics has demonstrated the first autonomous, untethered, entirely soft robot. This small, 3D-printed robot – nicknamed the octobot – could pave the way for a new generation of completely soft, autonomous machines.

Soft robotics could 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.

“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. 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, i.e. 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 a balloon.

“Fuel sources for soft robots have always relied on some type of rigid components,” said Michael Wehner, Wood lab. “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, 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 3D printing – we can quickly manufacture these devices,” said Ryan Truby, a graduate student in the Lewis lab. 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.” https://www.seas.harvard.edu/news/2016/08/first-autonomous-entirely-soft-robot