3D printed robots come in all shapes and sizes – we’ve seen cute robots, robots that can crawl, or walk on 3D printed legs, robots that resemble eels, and humans, and even biohybrid robots based on sea slugs. This last robot was the result of a project at the Cleveland, Ohio-based Case Western Reserve University (CWRU). Now, a different team of CWRU researchers, led by Nord Distinguished Assistant Professor of Mechanical and Aerospace Engineering Kiju Lee, have designed a soft, flexible robot, using 3D printing technology, that’s inspired by the origami Lee enjoyed growing up. The patent-pending, novel mechanism is known as TWISTER (TWISted TowEr Robot).It’s not the first time we’ve seen 3D printing, robotics, and origami combined, and I’m certain it won’t be the last, as these three combined technologies can be used for many different kinds of applications. The TWISTER robot was inspired by an origami twisted tower, which was originally designed by Mihoko Tachibana, a Japanese artist. The twisted tower uses several origami segments to form a tower structure. This specific design was later reinvented to be used in the manufacturing and robotics field.
Lee and her team – current and former undergraduate researchers Yanzhou Wang and Evan Vander Hoff, and PhD students Donghwa Jeong and Tao Liu – started out working with paper-folded structures, using multiple layers of regular polygons, like hexagons and triangles, to form the tower’s tube-like shape.
Once they had the construction down, they added three small towers to the end of one large tower, and then manipulated the smaller towers to grasp, similar to opposing fingers. The researchers discovered that when the structure was picking up and moving objects like ripe fruit and eggs, if they applied excessive force, the fingers would then absorb this “by distributing it and deforming.”
The team says that this quality of distributing and deforming the force demonstrates the potential the design has for manipulating other fragile objects, in a more advanced manner than this 3D printed grasper device, without having to use force-based sensing. It also means that it could safely interact with humans.
“TWISTER is very different from rigid body robots.”
In manufacturing processes, hard-bodied robots are usually kept separated from humans for safety issues.
“Because this robot can be made with soft materials, it could be safe to use on an assembly line right next to people,” Lee explained.
Lee and her team have successfully moved on from paper robots and converted the designs for TWISTER into 3D printable models. Then, the team was able to take the work one step further and fabricate complex, 3D printed designs, based on the original origami twisted tower, that can twist, extend, and contract. Cable-based actuation is used to control the robot, and the researchers are also looking into different approaches, like using Shape Memory Alloys to make a tower lying on its side crawl.
While the origami-inspired TWISTER definitely has applications on the assembly line in factories, Lee has also been working with physicians to find a way to miniaturize TWISTER so it can be inserted into a person’s body for minimally invasive surgical procedures.
Lee said, “Laproscopic surgery often requires some rigid pieces, and movement to control them from the outside causes stress on the tissues.”
She is also looking into applications for the TWISTER robot in outer space, like a robotic, twisting and grasping space arm.
“To put anything into space, volume and weight are critical, because of the cost of rocket transport. This robot is fully collapsible and, compared to a rigid arm, light and compact,” Lee explained.
Yesterday, Lee presented her TWISTER study at the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) in Vancouver, which ends today. The theme is “Friendly People, Friendly Robots,” so I’m sure TWISTER fit in just fine.
If you want to see the TWISTER in action, take a look at the CWRU video below:
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