by Olov Lundgren Kuosmonen and Lola Naraha Jönsson, students at Jönköping University

In this article we are going to explore our thesis about implementing origami in Additive Manufacturing. Origami, which is an antique Japanese paper folding technique, has been used for engineering purposes even before. Engineering related problems such as achieving compactness, re-configuration etc. have been solved by implementing origami. When we saw a solar panel achieve great changes in size with the help of implementing origami structures, we discovered a great opportunity to apply this in Additive Manufacturing. The advantages of this are that the solar panel can be folded and take up less space when transporting it to space. While in space the solar panel can be deployed to its form of usage.

As such, our goal was to print a product with larger dimensions than what a printer could traditionally support with the help of origami. So, by using origami to print an application, space in the printer could be saved, due to the technique’s compactness. The way we applied origami to Additive Manufacturing was through constructing a foldable product with the help of an origami structure, while considering the manufacturing requirements for AM. The next step was to print it in a folded state and afterwards deploy it to its form of usage.

To research this topic, we applied it on an antenna reflector dish. The reflector had a diameter of around 650 mm and had a depth of around 95 mm. The printer, which would manufacture it ,was a SLS-printer named EOS P 396 with a build volume of 340x340x600 mm. Research topics that were mostly studied for our thesis were structures for engineering applications and mechanical solutions. These fields covered the design of the antenna reflector and answered questions like: How would the product mechanically fold? and Which parts of the product are going to be folded?

The reason why we were interested in researching this topic was to find new ways of manufacturing products and extending the use of Additive Manufacturing. This research is covering the very basics of the idea about implementing origami in Additive Manufacturing; however, this can be furthered developed. We covered one field of usage: compactness, but we believe it can contribute to other fields e.g., re-configurable products with complex designs. Due to just having basic knowledge about Additive Manufacturing, AMEXCI helped the research move forward by sharing their knowledge and feedback on our design of the origami structure. This topic has a very small coverage, which made it essential to discuss our findings with the experts at AMEXCI.

What we did

During our research we found some very interesting papers that helped us gain inspiration and knowledge about this topic and even seek methods that could be used for designing the origami structure.

We decided to research three different types of mechanical solutions for the folding: traditional hinges, living hinges and concealed hinges. The summary stated that either traditional hinges or living hinges suited best for our project. After printing several different types of traditional hinges and living hinges, we decided to choose traditional hinges due to its reliability. If we had more time to research living hinges, then we would probably have found a suitable solution as well.

For the development of the origami structure, we used the method called Brainstorming. With this method we put together three different design concepts for evaluation. The first one took inspiration from the solar panel we wrote about before. We used the same origami structure and applied it on the antenna reflector dish. The solar panel which we took inspiration from is flat and the antenna reflector dish that we applied the origami structure on had a depth. This produced panels that were colliding when folding the structure. The second concept took inspiration from an umbrella-like folding technique where every other layer of panels folds up or down. The conclusion we got from this concept were that it would probably not effectively fit in the printer. For the last concept we used a method called Unfolding Polyhedra. This method is developed by Edwin A. Peraza Hernandez, Darren J. Hartl and Dimitris C. Lagoudas[1]. This method helped us find a way to fold one of our origami structures that we developed through brainstorming. This concept was the most promising one to further develop. For the final concept we wanted to minimise the weight and the material waste. This was solved by adding a lattice structure on the back of the antenna reflector dish.

For the first iteration that was manufactured with the SLS-printer, four hinges melted together and broke when we tried to deploy it. It was also noticeable hard to remove the powder from the hinges, which made it hard to deploy the antenna reflector dish in general. We tried to solve this problem by making powder-openings in the hinges and by increasing the tolerances between the parts. The second iteration of the antenna reflector dish was easier to deploy, but the hinges became weaker due to the re-design. The antenna reflector dish broke into three parts. After evaluation we think this type of problems can easily be fixed. We believe our concept was successful enough to say that further development for implementing origami in AM can be a new way to manufacture products and extend the usage of Additive Manufacturing.

Conclusion

The result we got from our thesis is that we were able to fit our product in the printer given to us. We managed to fold the antenna reflector dish to a 2,4 times smaller size, but the problems occurred after it was printed. More profound research about different hinges that are more suitable for Additive Manufacturing is needed to get reliable products and manufacturing process. Even though we did not get the outcome that we wanted, we still got interesting results that will support the research topic. It is a very unexplored topic, and we are happy that we choose to do something innovative and hopefully inspiring!

[1] [Darren J. Hartl, Dimitris C. Lagoudas, Edwin A. Peraza Hernandez, ”Unfolding Polyhedra Method for the Design of Origami Structures with Creased Folds”, Active Origami, Springer, 2019, pp. 111-155.]