An origami drone invented at EPFL is able during collisions to soften to avoid breakage. Inspired by insect wings and combining the advantages of flexible and rigid structures, it then returns to its original form.
For several years, roboticists have been drawing on origami – traditional Japanese folding – to make robots and drones light and foldable, said Wednesday the Swiss Federal Institute of Technology Lausanne (EPFL) in a statement.
So far, two types of structures have prevailed. Rigid structures, capable of supporting a certain weight, but breaking when the load is too heavy, and flexible and resilient structures, can hardly support a load.
The Lausanne researchers have developed a hybrid origami drone inspired by insect wings, which can be rigid or flexible depending on the needs. During the flight, the drone has a rigid state, to support the weight of its structure, and withstand the thrusts caused by the propellers.
But in the event of a collision, it is able to soften to absorb the shock. This ability of deformation makes it possible to limit as much as possible the material damage. Led in the Laboratory of Intelligent Systems, directed by Dario Floreano, the research is published in Science Robotics.
The drone owes its resistance to its particular construction in rigid and elastomeric layers.
An elastomeric membrane is stretched and sandwiched between rigid wafers.
When the system is at rest, the pads are held together and impart rigidity to the structure. On the other hand, if a force of sufficient intensity is exerted, the wafers move apart and the structure can bend.
“During manufacturing, we can encode various mechanical properties in the drone,” said Stefano Mintchev, first author of the study, in a statement: “It is possible to decide the moment of transition between the rigid and flexible state , for example”.
Another advantage, by folding it on itself, the drone stores potential elastic energy, which allows it to self-deploy at the desired time. In addition, the ability to program structures that are both rigid and flexible opens the door to various applications.
The researchers have used this technique to make a delicate finger grip. Passed a certain pressure, the pincer softens, avoiding to break the object to grasp. In the same way, the system prevents the gripper from carrying a load that is too heavy compared to its capacity.
“The trend in robotics is to make robots that are more ‘soft’, adaptable and able to work with people in a safe way, but for some applications, some rigidity is needed,” explains Dario Floreano. “With our system, we have demonstrated that it is possible to reconcile the two states,” concludes the specialist.