By Jonathan Webb Science reporter, BBC News
25 August 2016
US engineers have built the first ever self-contained, completely soft robot - in the shape of a small octopus.
Made from silicone gels of varying stiffness, the "octobot" is powered by a chemical reaction that pushes gas through chambers in its rubbery legs.
Because of this design, the robot does not need batteries or wires - and contains no rigid components at all.
Instead, a sequence of limb movements is pre-programmed into a sort of circuit board built from tiny pipes.
These movements aren't good enough, yet, to send the octobot out for a stroll; instead it sits in one place and pumps alternating legs up and down in a very slow, eight-legged can-can.
But because that dance is powered purely by the robot's internal pneumatic system, the Harvard researchers - writing in the journal Nature - say their system marks a key step forward for soft robotics.
"Many of the previous embodiments required tethers to external controllers or power sources," said PhD student Ryan Truby from Harvard University.
"What we've tried to do is actually to replace these hardware components entirely and have a completely soft robotic system."
The hope is that one day, soft robots will wiggle their way into awkward surgical locations or squeeze under obstacles on search-and-rescue missions.
Real-world tasks like these, particularly if they involve human interaction, are challenging or even impossible for conventional, rigid robots - which are much more comfortable in the structured, repetitive environment of the factory floor.