The December 2022 issue of IEEE Spectrum is here!

Close bar

Top Half of a Robot Giraffe

The power and flexibility of giraffe necks have inspired a new robot in Japan

3 min read
On left a giraffe from the neck up browsing on a tree, on right a skinless robotic giraffe neck with a giraffe skull on top

This article is part of our exclusive IEEE Journal Watch series in partnership with IEEE Xplore.

When we think about flexibility in bioinspired robots, the best examples can usually be found in soft robots that mimic octopus arms or elephant trunks, which have some unique capabilities. But most animals are soft and flexible to some extent, just typically coupled with a rigid interior structure. It’s a complex arrangement, albeit one with some significant advantages in power and control.

Researchers at the Tokyo Institute of Technology have been experimenting with mimicking what is arguably one of the most impressive combinations of flexibility and power in the animal kingdom: the neck of the giraffe. Giraffe necks can weigh up to 150 kilograms and be 2 meters long, but they’ve evolved to be bendy and strong, not just to get those tasty high-growing leaves but also because male giraffes battle each other with their necks, occasionally to the death. What better inspiration for designing large robots, right?


As a first step toward realizing a powerful and flexible robot, we built a half-scale musculoskeletal robot, mimicking the structure and mechanism of the giraffe neck based on anatomical knowledge, and reproduced part of its characteristics.
The mechanism consists of a skeletal mechanism fabricated using a 3D printer, a gravity-compensation mechanism mimicking nuchal ligament using rubber material and tensioners, a redundant muscle driving system using thin artificial muscles, and a particular joint using rubber disks and mimicking ligaments.

The robotic giraffe neck does its best to mimic the structure of an actual giraffe neck (the paper includes a photo of the partially dissected neck of a real giraffe), with vertebrae and tendons arranged similarly—and thin McKibben pneumatic artificial muscles providing contracting forces the same way real muscles do. It’s complicated, but it enables a significant amount of flexibility:

Photo collage showing the different parts of the robotic giraffe neck along with photos showing the neck flexing partway around a cylinderTokyo Institute of Technology

The authors of the paper helpfully point out that giraffes are able to leverage the power and flexibility of their necks in contact with each other nondestructively, which is not something conventional mechanical systems can do:

Thus far, researchers have not developed machines or robots having similar powerfulness and flexibility characteristics on par with the giraffe’s neck. For example, if two actual industrial cranes fight, it would be easy to imagine that the damage would be catastrophic, resulting in two broken cranes.

I am now trying to imagine two actual industrial cranes fighting, which would almost certainly look nothing like this:

Compare this to real giraffes necking, which is both less destructive and doesn’t do weird things to a classic comic:

National Geographic

Anyway, the researchers suggest that developing a robotic system with a practical combination of power, flexibility, and control might be more straightforward to do with a giraffe neck model than an elephant trunk model. You’d sacrifice some softness and flexibility, but you might be able to actually make it work in a way that could execute the amount of force required to be useful in industrial applications.

The name of this robot is Giraffe Neck Robot #1, which, while not the most creative, does suggest that other robots will follow. From the sound of things, the next step will be cranking up the power by several orders of magnitude (!) by using hydraulic rather than pneumatic actuators.

Giraffe Neck Robot: First Step Toward a Powerful and Flexible Robot Prototyping Based on Giraffe Anatomy, by Atsuhiko Niikura, Hiroyuki Nabae, Gen Endo, Megu Gunji, Kent Mori, Ryuma Niiyama, and Koichi Suzumori from Tokyo Institute of Technology is published in IEEE Robotics and Automation Letters.

The Conversation (0)

The Bionic-Hand Arms Race

The prosthetics industry is too focused on high-tech limbs that are complicated, costly, and often impractical

12 min read
Horizontal
A photograph of a young woman with brown eyes and neck length hair dyed rose gold sits at a white table. In one hand she holds a carbon fiber robotic arm and hand. Her other arm ends near her elbow. Her short sleeve shirt has a pattern on it of illustrated hands.

The author, Britt Young, holding her Ottobock bebionic bionic arm.

Gabriela Hasbun. Makeup: Maria Nguyen for MAC cosmetics; Hair: Joan Laqui for Living Proof
DarkGray

In Jules Verne’s 1865 novel From the Earth to the Moon, members of the fictitious Baltimore Gun Club, all disabled Civil War veterans, restlessly search for a new enemy to conquer. They had spent the war innovating new, deadlier weaponry. By the war’s end, with “not quite one arm between four persons, and exactly two legs between six,” these self-taught amputee-weaponsmiths decide to repurpose their skills toward a new projectile: a rocket ship.

The story of the Baltimore Gun Club propelling themselves to the moon is about the extraordinary masculine power of the veteran, who doesn’t simply “overcome” his disability; he derives power and ambition from it. Their “crutches, wooden legs, artificial arms, steel hooks, caoutchouc [rubber] jaws, silver craniums [and] platinum noses” don’t play leading roles in their personalities—they are merely tools on their bodies. These piecemeal men are unlikely crusaders of invention with an even more unlikely mission. And yet who better to design the next great leap in technology than men remade by technology themselves?

Keep Reading ↓Show less