Self-folding origami robots assemble themselves

Inspired by origami, the Japanese paper-folding art form, researchers from Harvard University and the Massachusetts Institute of Technology have developed a flat sheet of composite material that can pop up and assemble itself into a robot in less than four minutes. It can then crawl away at a speed of more than two inches per second, all without human assistance.

The new innovation allows speedy production of complex robots in various sizes that are lightweight, yet very durable, the researchers reported in the journal Science. The cost-efficient robots can be shipped flat and assembled onsite. They are ideal for mass production because they can be built rapidly with inexpensive tools like laser cutters rather than expensive traditional machinery and slow 3D printing.

The robots are constructed from flat sheets of paper and shape-memory polymers that change shape when heated above 100 degrees Celsius. Special software creates detailed crease patterns and automates the folding process, enabling the creation of a wide variety of structures and machines. The sheets are embedded with electronics and hinges containing heating circuits that create the heat required to trigger unfolding. In the case of the study’s demonstration robot, the stiffness and pattern of folds raised the robot’s body and propelled the legs to a downward angle, the researchers explained.

The new technology may have limitless uses, including military deployment, search-and-rescue operations, space exploration, self-assembling furniture, or self-folding shelters that can rapidly assemble in disaster zones. The robots could be delivered through a confined passageway, such as a collapsed building, and then assemble themselves into their final form, said Marc Lavine, a senior editor at Science.

Other researchers also are experimenting with origami-based engineering. Researchers from Cornell University are working to build lightweight, ultra-tough material that can be constructed out of medium-sized building blocks and programmed with computer-controlled actuators. In the future, they hope to use the technology to build complex machines such as deployable barriers.

Researchers from Harvard Microrobotics Lab and Seoul National University in South Korea employed the magic ball pattern, a traditional origami technique used to make a paper sphere, to create robotic wheels that can automatically enlarge or shrink to the size necessary to complete a task, according to a report in IEEE Spectrum magazine. By changing its size, the machine can alter its own speed, force, or torque. Fixed-size wheels can be designed for speed or for power to haul, but they can’t do both. This design allows the robots to move quickly, crawl over objects of varying sizes, or haul objects simply by changing their own wheel radius without human adjustments. If a heavy load causes the robot to stall, the wheel hubs collapse to increase torque and allow them to keep moving, the researchers explained. Scientists hope this ability may be useful one day for interplanetary rovers.