Some living organisms feature an unusual muscle structure, which allows them to control the stiffness of their body, or various parts of it. Examples include elephants' trunks, our tongues, and octopus tentacles. Researchers working on the Octopus Project have so far successfully designed a robotic tentacle, with the ultimate aim of creating a full-bodied robotic octopus.

Why an octopus? According to the researchers, it has a number of characteristics that are interesting from an engineering point of view, such as an infinite number of degrees of freedom, various bending possibilities, controllable stiffness and high dexterity.

Such an octobot could be used in underwater search, rescue and exploration, Discovery News reports. "The applications we envisage are all the applications where you send the robot into very small spaces for exploration tasks but also for rescue under debris," stated team member Cecilia Laschi. British surgeons are also reportedly looking into applying the technology to an endoscope.

The working robotic tentacle prototype is approximately 17 inches (43 cm) long. The arm is fashioned from a central steel cable with a number of nylon cables attached to it, all of which are encased in a silicone skin. It's capable of grasping objects via manipulation of the cables, which allows it to stiffen around a target.

It's modeled after a real Mediterranean octopus.

The Octopus Project is an interdisciplinary initiative funded by the European Comission, and coordinated by the Scuola Superiore Sant'Anna educational institute in Pisa, Italy. The full robotic octopus with eight arms is scheduled for completion by the project's deadline in January 2013.

The following video presents the prototype tentacle: