Meet the soft, cuddly robots of the future

Rigid robots step aside — a new generation of squishy, stretchy machines is wiggling our way.

 n 2007, Cecilia Laschi asked her father to catch a live octopus for her seaside lab in Livorno, Italy. He thought she was crazy: as a recreational fisherman, he considered the octopus so easy to catch that it must be a very stupid animal. And what did a robotics researcher who worked with metal and microprocessors want with a squishy cephalopod anyway?

Nevertheless, the elder Laschi caught an octopus off the Tuscan coast and gave it to his daughter, who works for the Sant'Anna School of Advanced Studies in Pisa, Italy. She and her students placed the creature in a saltwater tank where they could study how it grasped titbits of anchovy and crab. The team then set about building robots that could mimic those motions.

Prototype by prototype, they created an artificial tentacle with internal springs and wires that mirrored an octopus's muscles, until the device could undulate, elongate, shrink, stiffen and curl in a lifelike manner¹. “It's a completely different way of building robots,” says Laschi.

This approach has become a major research front for robotics in the past ten years. Scientists and engineers in the field have long worked on hard-bodied robots, often inspired by humans and other animals with hard skeletons. These machines have the virtue of moving in mathematically predictable ways, with rigid limbs that can bend and straighten only around fixed joints. But they also require meticulous programming and extensive feedback to avoid smacking into things; even then, their motions often become erratic or even dangerous when dealing with humans, new objects, bumpy terrain or other unpredictable situations.

Robots inspired by flexible creatures such as octopuses, caterpillars or fish offer a solution. Instead of requiring intensive (and often imperfect) computations, soft robots built of mostly pliable or elastic materials can just mould themselves to their surroundings. Although some of these machines use wires or springs to mimic muscles and tendons, as a group, soft robots have ditched the skeletons that defined previous robot generations. With nothing resembling bones or joints, these machines can stretch, twist, scrunch and squish in completely new ways. They can transform in shape or size, wrap around objects and even touch people more safely than ever before.

Building these machines involves developing new technologies to animate floppy materials with purposeful movement, and methods for monitoring and predicting their actions. But if this succeeds, such robots might be used as rescue workers that can squeeze into tight spaces or slink across shifting debris; as home health aides that can interact closely with humans; and as industrial machines that can grasp new objects without previous programming.

Researchers have already produced a wide variety of such machines, including crawling robotic caterpillars², swimming fish-bots³ and undulating artificial jellyfish⁴. On 29–30 April, ten teams will compete in Livorno in an international soft-robotics challenge — the first of its kind. Laschi, who serves as scientific coordinator for the European Commission-backed sponsoring research consortium, RoboSoft, hopes that the event will drive innovation in the field.

“If you look in biology, and you ask what Darwinian evolution has coughed up, there are all kinds of incredible solutions to movement, sensing, gripping, feeding, hunting, swimming, walking and gliding that have not been open to hard robots,” says chemist George Whitesides, a soft-robotics researcher at Harvard University in Cambridge, Massachusetts. “The idea of building fundamentally new classes of machines is just very interesting.”

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