Take a Load Off with Origami

Recent technological advancements have given rise to very capable unmanned aerial vehicles (UAVs) with capabilities that make them suitable for a diverse range of applications. These aircraft operate without a human pilot onboard and are controlled remotely or, in some cases, autonomously. They range in size from small hobbyist models to large military-grade aircraft, and their versatility makes them useful in fields such as agriculture, surveillance, search and rescue, delivery, entertainment, and more.

Despite these promising applications, UAVs face a number of limitations due to their high levels of energy consumption. The vast majority of drones are powered by batteries, which have limited capacity and result in relatively short flight times. This can restrict their practical use in many scenarios, particularly those requiring long endurance or extended coverage areas. As technology advances, finding more sustainable and efficient power sources for UAVs will be crucial to fully realize their potential.

But until those future power sources materialize, we will have to make the most of what we have. One of the most effective ways of stretching the flight time of a drone is to reduce its weight. A team at the Shibaura Institute of Technology in Japan has found a very interesting way to do just that. They have designed and built a lightweight grasping mechanism that can be used to pick up relatively heavy objects while only adding five grams of weight to a UAV. Despite its minimal mass, this gripper can hold over 25 times its own weight.

In order to accomplish this feat, the researchers turned to an often overlooked material — paper. While it is light in weight, paper does not offer sufficient strength to serve as an effective grasping mechanism. But when origami techniques are applied to form it into a three-dimensional structure, it can become much stronger. Moreover, the paper can also be given a functional form that allows it to, for example, pick up an object and hold it tightly.

That sort of function traditionally only results from very complex patterns of paper folding, which makes fabrication processes very difficult. But by leveraging processes that they have been developing for a number of years, the team was able to define a simple process for fabricating their gripper. With just a cutting machine and an inkjet printer, paper can be cut into a specific pattern. When wetted by ink, this paper will then self-fold into a desired three-dimensional shape.

Using this technique, a gripper with a bistable structure was produced. When sufficient force is applied to the structure, it will snap into a secondary conformation. The researchers described it as transforming from a mountain into a valley — and whatever it comes into contact with that causes this transformation will be caught up in the valley that is created.

The gripper may only be one piece of the puzzle, but the reduced weight will give drones equipped with grasping systems more flight time. This approach also has the advantage of using fully biodegradable materials. When the grippers are damaged or otherwise no longer needed, they can be discarded without harming humans or the environment in any way.