From super-intelligent problem-solving, to camouflage smart materials and speedy jet propulsion, to robotic tentacle-like arms, the humble octopus is inspiring human innovation in unexpected ways.
With its eight tentacles, large eyes and intelligent behaviour, the ‘alien’ of the ocean, the humble octopus, is now the inspiration for a whole raft of new technology from smart materials to robotic arms.
Octopus: scientific name – Octopoda - a cephalopod mollusc with eight sucker-bearing arms, a soft sac-like body, strong beak-like jaws, and no internal shell.
Except it’s so much more than that. In fact, the octopus is an animal so smart that it’s the only invertebrate to be given special protection under UK law governing the licensing of animal experiments. What’s more, scientists have now decoded the genome of the octopus and, armed with 10,000 more genes than humans, they’ve discovered just how different it is from other intelligent creatures both on land and sea. It’s no wonder that this extraordinary differentiation is informing today’s technological advances.
The octopus has long been a source of human fascination, feeding into myth and maritime folklore as well as science fiction, from Marvel’s Doctor Octopus, the myopic mad scientist hell-bent on destroying Spider-Man using his four powerful, mechanical tentacles, pictured above, to Jules Verne’s 1870 novel Twenty thousand leagues under the sea, which sees the Nautilus under attack from a pack of giant poulpes. However, it is precisely this oddness, feeding into our wildest imaginings, that sets this creature apart and prompts us to look in more detail at how it actually operates.
“The octopus appears to be utterly different from all other animals, even other molluscs, with its eight prehensile arms, its large brain and its clever problem-solving capabilities,” says Clifton Ragsdale of the University of Chicago, one of the leaders of the international genome-sequencing project.
“It is an incredible resource that opens up new questions that could not have been asked before about these remarkable animals,” he adds.
The discovery of its genome has already thrown up genes that are likely to be involved in the unique adaptive coloration of the octopus, which allows it to change its skin colour to match its background.
Researchers from the University of Bristol's Department of Engineering Mathematics have harnessed this unique camouflage process to create an artificial smart skin that can be transformed at the flick of a switch to mimic the camouflage abilities of octopus and squid.
The team’s smart materials system is inspired by biological chromatophores, the small pigmented cells embedded on cephalopods’ skin that expand and contract when stimulated by their surroundings, working together to change skin colour and texture.
Published in Interface, the Journal of the Royal Society, the research shows that artificial skin made from electroactive dielectric elastomer, a soft, compliant smart material, can effectively copy the action of these biological chromatophores.
The artificial chromatophore cells can sense their surroundings and be electrically manipulated in order to change. In this way, the team members were able to mimic the complex dynamic patterning seen in real cephalopods such as the ‘Passing Cloud’ display, where bands of colour spread as waves across the skin, a visual effect used in nature to distract and divert predators.
Commenting on their efforts, Aaron Fishman, visiting fellow in engineering mathematics, said: “Our ultimate goal is to create artificial skin that can mimic fast-acting active camouflage and be used for smart clothing such as cloaking suits and dynamic illuminated clothing.”
Inspired by the speed at which cephalopods like the octopus flee from danger, scientists at the Singapore-MIT Alliance for Research and Technology (SMART) have developed an octopus-inspired robot that can speed through water ten times its body length within one second.
Octopuses achieve this form of jet propulsion by inflating their mantle cavities with water to form a bluff-body shape (broad, flattened front), and then quickly expel it to propel themselves away from danger. This ability holds the key to the application of ultra-fast propulsion and super-manoeuvrability in underwater vehicles. The research validates the physics of shape change, that forms the basis of jet propulsion in cephalopods, and with it, the capability to provide additional thrust to underwater vehicles.
Researchers have created a polycarbonate 3D-printed streamlined skeleton with no moving parts and no energy storage device other than a thin elastic outer membrane. It works like blowing up a balloon and then releasing it to fly around the room. The 27cm-long robot is inflated with water and once released, rapidly deflates by shooting the water out through an aperture at its base to power its propulsion. As the rocket contracts, it can achieve more than 2.6 times the thrust of a rigid rocket doing the same manoeuvre, while creating minimum turbulence, an important feature in underwater research and survey vehicles. The skeleton within the robot keeps the shape streamlined and tail fins help stabilise it.
Professor Michael Triantafyllou, the William I Koch professor of marine technology, professor of mechanical and ocean engineering and director of the Center for Ocean Engineering at MIT, explains: “With this fundamental understanding in fluid mechanics, our research will pave the way for future robots that require fast manoeuvres to help us get close to something that moves fast or quickly evade hazardous situations such as a sharp temperature rise in mid-ocean ridges. For instance, these octopus robots could follow dolphins for quick observation, or inspect thermal vents safely in the mid-ocean ridges.”
Need an extra pair of tentacles?
Help is at hand. Researchers at the d’Arbeloff Laboratory at the Massachusetts Institute of Technology (MIT) have created lightweight, wearable robotic arms. The supernumerary robotic limbs (SRLs) slip on like a backpack and are mounted either on the shoulders or at the waist - think Doctor Octopus (although not embedded in your actual flesh)!
They’re not designed to replace biological limbs, but to augment the number of limbs a person already has, with the aim of streamlining tasks and helping to prevent injury for workers who perform repetitive, difficult tasks.
Each arm has five degrees of freedom (the number of independent parameters that define its configuration), with interchangeable and customisable end effectors, with the complete system weighing in at 4.5kg. The SRL watches what you're doing with your real, human arms to decide how to move, by monitoring two inertial measurement units (IMUs) that the user wears on the wrists. A third IMU sits at the base of the robot’s shoulder mount, to track the overall orientation and motion of the SRL.
The SRL uses the gyro and accelerometer data from the IMUs to make a prediction about what would be the most helpful, proactive position for its own robot arms. If you put your arms up above your head, for example, the robot arms will also rise - never again will you have a problem flagging down a taxi. Using their SRL prototype, the researchers are testing different behavioural modes with which to program the limbs.
“Once we combine the most significant behavioural modes we are able to control the robot such that, from the wearer's perspective, it behaves like an extension of his [or her] own body,” says Baldin Llorens-Bonilla, a researcher at the d'Arbeloff Laboratory at MIT.
The octopus has inspired much human technological innovation, and with good reason. This smart cephalopod is unique. Indeed, the late British zoologist and renowned cephalopod expert Martin Wells, grandson of the pioneering author HG Wells, was one of the first to claim the octopus to be an alien, the first intelligent species on Earth.
The sequencing of its genome is helping to shed light on how the octopus has evolved, uncovering astounding new information about its unique brain and morphology that, in turn, will inform a new generation of novel technologies and human endeavour.