06/12/2018 / By Edsel Cook
You may have seen examples of origami artwork, which are made from colorful folded paper and are surprisingly strong. Korean researchers borrowed from that ancient art style to design a folding robotic arm that can assemble itself, according to a NanoWerk article.
The robot arm relies on variable stiffness, where actuators can change their rigidity no matter what their position is. It can change its shape using only one wire, which works well with its origami-based structure.
Developed by a research team from Seoul National University, the arm is capable of changing its stiffness at the drop of a hat. It weighs very little and is so thin that it can be folded flat or extended as if it were an umbrella.
Most items inspired by origami find it difficult to resist hard impacts because of their thinness. But the robotic arm features a collapsible locker that can protect it from such sharp shocks.
Professor Kyu-Jin Cho and his study team took a concept from origami where two perpendicularly folded lines create a surprisingly stiff shape. They based their variable stiffness actuator on this principle.
The Korean researchers ended up with a hexagonal structure about 10 cm long and weighing less than 30 g. But the small shape can support a 12-kg load that is more than 400 times its weight.
In addition to being incredibly strong, these lockers are easy to unlock. The entire structure can be flattened by pulling on a single wire, which is routed through the arm in such a way that it unlocks the mechanism in sequence.
When a small motor pulls on the wire, it simultaneously unlocks the actuator and closes the robot arm. Once the protective lockers enter the module, the actuator moves and unlocks the structure, allowing it to be folded without a fuss.
This wire-driven actuator is very easy to increase or decrease in size. It can be used in multiple modules, such as a serially connected robot arm. (Related: Robot with advanced cyber-hand put to work harvesting cauliflower for the EU.)
The origami-inspired robot arm can be fitted on the tiny toy-sized drones your kid might be playing with in your backyard right now. Those drones can carry very little weight, but the new arm can give them a way to interact with their surroundings without causing weight issues.
In their demonstration, the Korean researchers fitted one such drone with their prototype robot arm. The new limb folded flat to stay out of the way whenever the small machine is taking off, moving through the air, or landing on the ground.
When the drone reaches a target, it unfolded the robot arm and uses it to grab the object with little problem.
According to Cho, his team’s origami-based variable stiffness technology can be used by other robots and structures. Their robot is sturdy enough to be used in polar regions, deserts, underwater, and even space.
He says that soft robots can move more flexibly than traditional rigid robots. But their soft structures will get deformed and damaged if they are forced to support heavy loads.
The robotic arm developed by Cho and his team enjoys the best part of both robot types. Its variable stiffness technology can increase the strength of its structure when it needs to bear big weights and fold itself to save on room when it’s not in use.
To ensure the robot arm can handle high-load jobs or harsh environments, it is made from ripstop fabric and a specially treated plastic film.
You can find more articles on robotics technology at Robots.news.
Tagged Under: appendages, drones, future tech, origami, rigid robots, robot technology, robotic arm, robotics, robots, Seoul National University, soft robots, technology, variable stiffness technology