PULLMAN, Wash. – Washington State University-led researchers have developed a chip-sized processor and 3D printed antenna arrays that could someday lead to flexible and wearable wireless systems and improved electronic communications in a wide variety of auto, aviation, and space industry applications.
Reporting in the journal Nature Communications , the researchers used 3D printing, the processor, and an ink made from copper nanoparticles to create the flexible antenna arrays.
"This proof-of-concept prototype paves the way for future smart textiles, drone or aircraft communications, edge sensing, and other rapidly evolving fields that require robust, flexible, and high-performance wireless systems," said Sreeni Poolakkal, co-first author on the paper and a PhD student in WSU's School of Electrical Engineering and Computer Science.
Industries such as aviation and the auto industry would like to be able to use 3D-printed flexible, or conformal, antenna arrays because they could be lighter, smaller, and more flexible than traditional antenna arrays. So, for instance a drone could be fitted with a layer of antennas.
Because of their materials and the way they're made, however, flexible wireless systems have been too expensive to make and haven't performed as well as standard antenna arrays. When they move and bend, such as in wearable electronics or when an airplane wing is vibrating, the antennas change shape, causing errors in their signals.
The WSU-led team used 3D printing and an ink made from copper nanoparticles to create antennas that remain stable when they are bent or exposed to high humidity, temperature variations, and salt. The team's collaborators from the University of Maryland and Boeing developed the copper nanoparticle-based ink.
"The ink is a very important part in additive, or 3D printing," said Subhanshu Gupta, associate professor in the WSU School of Electrical Engineering and Computer Science and a co-author on the work. "The nanoparticle-based ink developed by our collaborators is actually very powerful in improving the performance for high-end communication circuits like what we're doing."
Because precision wireless communication needs significant fidelity, the researchers also developed a processor chip that can correct errant signals from the antenna in real time.
"We used this processor that we developed to correct for these material deformities in the 3D printed antenna, and it also corrects for any vibrations that we see," said Gupta. "The ability to do that in real time makes it very attractive. We were able to achieve robust, real-time beam stabilization for the arrays, something that was not possible before."
The researchers built and tested a lightweight, flexible array of four antennas that were able to send and receive signals successfully when the antennas were moving and bending. The small antennas use low power and can easily be scaled, making them ideal for implementation on devices. Because they're built as tiles, the array design enables building larger arrays, and individual processor chips on each of the tiles operate independently, said Gupta. The researchers were able to put together four of the antenna arrays to make 16 total antennas.
The work was funded by the Air Force Research Laboratory as well as by the Washington Research Foundation and the M.J. Murdock Charitable Trust Foundation. In addition to Poolakkal and Gupta, co-authors on the paper include Shrestha Bansal and Arpit Rao from WSU; Abdullah Islam, Zhongxuan Wang, and Shenqiang Ren from University of Maryland; Ted Dabrowski, Kalsi Kwan, Julio Navarro, and John Williams from Boeing Research and Technology; and Amit Mishra and Sudip Shekhar from University of British Columbia.
