Texas A&M researchers are creating origami-inspired satellite tv for pc antennas
Antennas are available in different designs. Their main function is to send or receive information in the form of electromagnetic waves. Some antennas, such as those used for communication between a television and a space-based satellite, are curved in the shape of a parabola. This ensures that the electromagnetic waves that hit the bowl-shaped antenna are reflected and converge to a small focal point. When these antennas send electromagnetic waves, it does so in a narrow direction, which is known as directivity.
Therefore, parabolic reflectors are a natural choice for space applications as they either pick up or send information in a specific direction. However, their shape makes it impractical to store in spacecraft with limited space. This problem is exacerbated when many antennas have to be stored on board.
One way to overcome this hurdle is with origami engineering. With this technique, flat 2D structures can be folded into complex 3D shapes. If parabolic antennas can be flattened with origami, they can be stacked or rolled up in a rocket. When ready to use, they can be rolled out and folded into a parabolic shape. However, Hartl stated that folding a piece of flat material into a smooth bowl is difficult and not intuitive.
“With traditional origami design, thin sheets of material are folded with sharp folds. Engineering structures, on the other hand, have thickness and the choice of material can make it difficult to get those sharp folds, ”he said. “So we have to create folds that curve evenly.”
To make the paper-like folding at the folds easier, researchers turned to shape-memory composites, which change shape when heated. In addition, these materials are inexpensive, light, flexible and can be stretched several times without being damaged.
First, they built a flat 2D surface from strips of shape memory composites and cardboard. Stiff pieces of cardboard that made flat facets were held together by the shape-memory composites, much like the ribs of an umbrella hold the fabric in place. They also cut out tiny holes at the corner points where the composites meet to serve as corner folds when the assembly folds into a 3D parabola.
When heated, the researchers showed that the composite materials changed their shape through systematic bending and finally lifted the pieces of cardboard into a parabolic shell-like shape. They also tested whether their multi-faceted parabolic reflector worked as efficiently as a smooth parabolic antenna and found that the two antennas performed comparable.
Hartl said this research is an important step in using the origami principles to create highly functional engineering structures that can be stowed compactly and easily deployed when needed.
“In addition to other applications, future advances based on this research are likely to result in reflector antennas being transformed for military and space telecommunications applications,” he said.
Other contributors to this research include Sameer Jape, Milton Garza, and Dimitris Lagoudas from the Aerospace Department; Joshua Ruff and Francisco Espinal from the Faculty of Electrical and Computer Engineering; Deanna Sessions and Gregory Huff from Pennsylvania State University; and Edwin A Peraza Hernandez from the University of California, Irvine.
This research is funded by the National Science Foundation and the Air Force Office of Scientific Research.