The research detailed in the paper “Continuous-range tunable multi-layer frequency selective surfaces using origami and inkjet-printing” published in the proceedings of the National Academy of Sciences shows that forming dipole elements across a foldable origami pattern using a simple inkjet-type printer yielded radio frequency filters whose adjustable dimensions would continuously change their characteristics, blocking different signals throughout a large range of frequencies.
The researchers also found that while a single-layer Miura-Ori-shaped filter only blocked a narrow band of frequencies, multiple layers of the filters could be stacked to achieve a wider band of blocked frequencies.
“The dipoles were placed along the fold lines so that when the origami was compressed, the dipoles bend and become closer together, which causes their resonant frequency to shift higher along the spectrum,” explained Manos Tentzeris, the Ken Byers Professor in Flexible Electronics in the Georgia Tech School of Electrical and Computer Engineering.
Such tunable filters could have a variety of uses, from antenna systems capable of adapting in real-time to ambient conditions to the next generation of electromagnetic cloaking systems that could be reconfigured on the fly to reflect or absorb different frequencies.
“The Miura-Ori pattern has an infinite number of possible positions along its range of extension from fully compressed to fully expanded,” noted Glaucio Paulino, the Raymond Allen Jones Chair of Engineering and a professor in the Georgia Tech School of Civil and Environmental Engineering. “A spatial filter made in this fashion can achieve similar versatility, changing which frequency it blocks as the filter is compressed or expanded.”
Because the Miura-Ori formation is flat when fully extended and quite compact when fully compressed, the structures could be used by antenna systems that need to stay in compact spaces until deployed, such as those used in space applications. Additionally, the single plane along which the objects expand could provide advantages, such as using less energy, over antenna systems that require multiple physical steps to deploy.
“A device based on Miura-Ori could both deploy and be re-tuned to a broad range of frequencies as compared to traditional frequency selective surfaces, which typically use electronic components to adjust the frequency rather than a physical change,” added Abdullah Nauroze, a Georgia Tech graduate student who worked on the project. “Such devices could be good candidates to be used as reflectarrays for the next generation of cubesats or other space communications devices.”
There were also physical advantages to using origami.
“The Miura-Ori pattern exhibits remarkable mechanical properties, despite being assembled from sheets barely thicker than a tenth of a millimeter,” explained Larissa Novelino, a Georgia Tech graduate student who worked on the project. “Those properties could make light-weight yet strong structures that could be easily transported.”
Georgia Institute of Technology – www.rh.gatech.edu