How researchers created an octopus-like robotic arm using origami

31 Aug 2021

An octopus-inspired origami robotic arm with 12 Kresling units. Image: Shuai Wu

Using Kresling origami, researchers made a robotic arm able to mimic the flexibility and motion of an octopus limb.

Whether it’s a simple swan or a detailed rose, origami structures have amazed and delighted in equal measure for centuries at the very least. Apart from creating beautiful pieces of art, origami has also made a significant contribution to technical achievements. Some scientists base medical stents on its techniques. Others are interested in what the practice could help achieve in structures.

Now, researchers have combined observations of octopuses with the ancient practice to create a folding, stretching omnidirectional robotic arm that is controlled using magnetism. The study, published in the journal PNAS, demonstrates a creative combination of nature, art and technology.

In this study, cylinders made from Tant origami paper that is only 0.14mm thick were used to form units of Kresling origami. Named after architect Biruta Kresling, the Kresling origami pattern is formed through the buckling of a thin, hollow cylinder in response to torque (rotational force).

By putting a magnetised hexagon plate at the top of the Kresling unit, the researchers were able to create movement. When the magnetic field causes the unit to rotate, the cylinder will either extend or bend, depending on how it is configured by the researchers.

These units can only extend or bend at one time but not both, so it was necessary to combine multiple units to achieve more complicated movement patterns. The study’s most advanced creation combined 18 of these plates to manufacture a robotic arm with the potential to bend, pick up and manipulate objects just like an octopus does.

“The octopus quickly reconfigures its arms to perform highly integrated tasks, such as swimming, walking and preying,” wrote the study’s authors.

“Inspired by such a soft-bodied cephalopod biosystem, we engineer compliant origami robotic arms to achieve multimodal deformations that integrate stretching, folding, omnidirectional bending and twisting for functions such as grasping and lifting objects by means of precise magnetic actuation.”

The researchers highlighted that by separating the power sources and controllers from the robotic systems, the remote magnetic controllers could manipulate the arm from a distance and would enable their creation to work in remote areas.

The researchers suggest that this could even work inside of the human body, allowing endoscopy and remote catherisation with robots in a scaled-down form. This would add to the already considerable contribution of the art of origami to the biomedical field.

Sam Cox was a journalist at Silicon Republic covering sci-tech news