Robotic 鈥渢entacles鈥� that can grasp and grapple with a wide variety of objects have been developed by US researchers.
Most robots rely on mechanical gripping jaws that have difficulty grabbing large or irregularly shaped objects. Replacing these with tentacle-like manipulators could make robots more nimble and flexible, say the scientists.
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The tentacle-like manipulators, known as 鈥淥ctarms鈥�, resemble an octopus鈥檚 limb or an elephant鈥檚 trunk. They were developed through a project called OCTOR (sOft robotiC manipulaTORs), which involves several US universities and is funded by the US Defense Advanced Research Projects Agency (DARPA).
鈥淎n elephant鈥檚 trunk can pick up a peanut or a tree trunk,鈥� says Ian Walker, a member of the project team from Clemson University in South Carolina. 鈥淭his ability, inherent in the OCTOR robots, gives OCTOR arms a huge advantage over conventional industrial robots.鈥�
Just like a real tentacle, an Octarm simply wraps itself around an object in order to manoeuvre it. This allows it to grasp objects of various sizes and shapes and could let robots deal with unpredictable real-world situations, the researchers say.
Narrow spaces
Each Octarm is powered by compressed air and has surface pressure sensors, positional sensors and a camera mounted at its tip. This allows the limb to nimbly investigate pipes, tunnels and other narrow spaces.
The Octarms developed so far are each around a metre long, although the design could easily be scaled up or down, the researchers say. Only one has been attached to a robot at a time, but the researchers say several could work together in future.
鈥淐oordinated control of multiple arms would be a real challenge,鈥� says Chris Rahn, another project member from Pennsylvania State University. But it is by no means impossible, he adds. He believes the robotic tentacles could perhaps one day be used to create a robotic octopus or even a backpack with extra limbs.
To create the manipulators, Bill Kier from the University of North Carolina and Roger Hanlon from the Marine Biological Laboratory, in Massachusetts, studied several types of flexible limbs found in nature, known as muscular hydrostats. These range from tongues and trunks to octopus tentacles. 鈥淭he octopus arm provided the best model,鈥� says Hanlon, 鈥渢he same basic arm structure appears in all seventeen species of octopus we studied.鈥�
Heavy and fragile
Tests involving an Octarm attached to an industrial robot showed that it could move irregular objects, lift fragile ones and explore pipes. Some Octarms were even successfully tested underwater. (55mb MPEG) created by the researchers shows the tentacles undergoing testing.
It is not clear what military purposes the Octarms will be used for, but the limbs have also been attached to Talon robots, which are typically employed for reconnaissance and bomb disposal tasks.
Like DARPA鈥檚 robotic 鈥減ack mule鈥�, BigDog, the robotic tentacles are part of DARPA鈥檚 Biologically Inspired Multifunctional Dynamic Robots (BIODYNOTICS) programme.
