Robots, by their nature, are rigid. They require actuators, logic boards, and other rigid components to operate. It’s this reliance on hardware and electronics that makes Harvard’s Octobot soft robot so fascinating. When creating Octobot, the engineering team was able to replace all the hardware and rigid parts with soft components that function together to create a completely soft, autonomous machine.
The octopus long has been a source of inspiration and innovation for those in the field of soft robotics. The sea creature is able to move deftly and is incredibly strong even though it does not have an internal skeleton. To replicate this soft-bodied animal, the team at Harvard had to think outside the box and experiment with 3D-printing, soft lithography, and molding, when replacing the rigid parts of the robot with analogous soft pieces. Not only did they create a completely soft robot, but the team also developed the Octobot to be autonomous, completely untethered from external controls.
The engineers relied on the chemistry of hydrogen peroxide and platinum to develop a pneumatic (gas)-powered propulsion system. A controlled reaction inside the robot converts liquid hydrogen peroxide into a gas that inflates the robot’s arms like a balloon. As the arms inflate and deflate, the octopus is able to move its limbs in and out at a slow pace to simulate crawling. This chemical reaction was controlled using a microfluidic logic circuit board pioneered by chemist George Whitesides of the Wyss Institute for Biologically Inspired Engineering at Harvard University.
This research is the first step in the development of more sophisticated soft robots capable of crawling, swimming and interacting with the environment in other ways. “This research is a proof of concept,” said graduate student Ryan Truby, who worked under lead researcher Jennifer A. Lewis of Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS). “We hope that our approach for creating autonomous soft robots inspires roboticists, material scientists and researchers focused on advanced manufacturing.”