This new robot arm - or should that be trunk?

This new robot arm - or should that be trunk? - from Festo of Denkendorf, Germany, is nothing if not graceful and flexible. But the firm says it also addresses the safety fears that have thus far kept industrial-scale robots and humans some distance apart.

Making robots safe for human interaction is one of the biggest drives in robotics research. Without smart sensing skins that keep the motion of lightweight limbs and motors from injuring people, experts say there will be no personal robotics revolution - robots will instead remain in their industrial safety cages, welding and spraying cars.

Not so, says Festo. Alongside the Fraunhofer Institute for Manufacturing Engineering and Automation in Stuttgart, it turned to 3D printing technology to make soft, compliant lightweight trunk segments that can nevertheless be steered by strong, pneumatically-powered artificial muscles hidden deep within.

Festo says its elephant's trunk-inspired limb, dubbed the Bionic Handling Assistant, is peppered with resistance sensors that limit its extension when it senses contact - potentially making it safe for anyone to use and interact with.

At the end of the "trunk", Festo has placed a novel gripper with three fin-shaped fingers comprised of collapsible compartments. As the outermost ends of these digits wrap around an object, they collapse and trap the object - so very little force is needed to grasp it, and the risk of injury is reduced.

"We are currently developing three sizes for gripping different types of objects - from hazelnuts to grapefruit. Test customers are already using the FinGripper in their production lines," says Festo on its website.

Despite its futuristic appearance, Festo's isn't the only odd robot arm in development. A European-wide team has developed something similarly flexible - but here the inspiration came from an octopus's limb. Instead of pneumatics, the EU team wants to drive their arm with "electroactive polymers" - smart plastics that bend when a voltage is applied.

Festo's decision to seek inspiration from a lumbering mammal marks a departure: it has previously created the most graceful of robotic penguins, jellyfish and manta rays.

And another German team has created the AirFish: an airship that wags its tail like a rainbow trout.