Octopus-Inspired Robot Matches Real Octopus For Speed

KentuckyFC writes: Underwater vehicles have never matched the extraordinary agility of marine creatures. While many types of fish can travel at speeds of up to 10 body lengths per second, a nuclear sub can manage a less than half a body length per second. Now a team of researchers has copied a trick used by octopuses to build an underwater robot capable of matching the agility of marine creatures. This trick is the way an octopus expands the size of its head as it fills with water and then squirts it out to generate propulsion. The team copied this by building a robot with a flexible membrane that also expands as it fills with water.

The fluid then squirts out through a rear-facing nozzle as the membrane contracts. To the team's surprise, the robot reached speeds of 10 body lengths per second with a peak acceleration of 14 body lengths per second squared. That's unprecedented in an underwater vehicle of this kind. What's more, the peak force experienced by the robot was 30 per cent greater than the thrust generated by the jet. The team think they know why and say the new technique could be used to design bigger subs capable of even more impressive octopus-like feats.

Comments

Underwater? Yes. Robot? NO

[OzPeter]

After reading TFA all they effectively did was design a toy-sized torpedo that uses an expanding membrane to hold the liquid used to propel the device. Nada más.

While they probably did do interesting work in fluid dynamics (IANAFD), in no way, shape or form could this even be remotely considered a robot.

Re:Underwater? Yes. Robot? NO

[Anonymous Coward]

http://en.wikipedia.org/wiki/Robot

"A robot is an automatic mechanical device often resembling a human or animal. Modern robots are usually an electro-mechanical machine guided by a computer program or electronic circuitry."

Quite a serviceable definition, and it covers what they are doing.

But even robot arms are robots: completely lacking in autonomy. Robotics generally is entirely the study of the kind of thing they are doing: studying the ways to make machines do things that are modelled on the way humans and animals do things.

Just because some robots tend towards looking like the kind of things we would no longer consider to be robots doesn't change the definition; we are instead surrounded by robotics.

Not "sustained" speed

[bradgoodman]

Creatures that use this form of population do it only for "bursts" - like to escape a predator. They cannot sustain this speed. If they used this form of propulsion for a submarine, that would be one hell of a jerky ride.