Origami, the art of folding pieces of paper to create shapes, is an appealing concept for robotics because you can transform two dimensional materials into three dimensional structures that are inherently flexible, or, as a roboticist would say, "deformable." What's more, structures that fold and unfold enable all kinds of interesting functionality that would otherwise only be possible with systems that are much more complex.
The approach can be particularly useful in designing wheels for robots, and earlier this month at the IEEE International Conference on Robotics and Automation (ICRA) two research groups presented origami-inspired wheel systems that allow mobile robots to be nimbler and stronger.
One of the groups was from Seoul National University's BioRobotics Laboratory, led by Professor Kyu-Jin Cho. Researchers there have designed a clever robotic wheel based on one of the most famous origami patterns, the magic ball pattern.
The wheel they created can change its radius by deforming its shape. This is a useful trick to be able to perform, since a wheel with a large radius is better at climbing over things, while a wheel with a smaller radius is better at squeezing under things, as the robot demonstrates in the video below.
The wheel and hooks together can deform from a minimum diameter of 55 millimeters to a maximum diameter of 120 millimeters, which is a substantial range, especially considering that the transformation only requires one single actuator per wheel.
"Fabrication of Origami Wheel Using Pattern Embedded Fabric and Its Application to a Deformable Mobile Robot," by Dae-Young Lee, Ji-Suk Kim, Jae-Jun Park, Sa-Reum Kim, and Kyu-Jin Cho from Seoul National University, was presented this month at ICRA 2014 in Hong Kong.
In another project presented at ICRA, researchers at the Harvard Microrobotics Lab, led by Professor Robert Wood, teamed up with the group from Seoul National University to design origami wheels that can automatically expand and shrink.
The goal in this case wasn't just allowing the robot to climb over some things and squeeze under other things. Since there's a direct relationship between the radius of a wheel and the torque that it can exert, a wheel that can deform can also act as an automatic, continuously variable transmission.