The evolution of wireless technology—including device charging and signal enhancement—depends on the development of antennas capable of transmitting electromagnetic waves that are more versatile, durable, and easily produced. Researchers from Drexel University and the University of British Columbia suggest that kirigami, an ancient Japanese technique of paper-cutting and folding to create complex 3D forms, could inspire the next generation of antennas.
The evolution of wireless technology—from device charging to signal enhancement—hinges on the antennas that convey electromagnetic waves becoming increasingly adaptable, robust, and straightforward to produce. A research team from Drexel University and the University of British Columbia proposes that kirigami, the traditional Japanese method of cutting and folding paper into intricate three-dimensional shapes, could serve as a blueprint for crafting the upcoming generation of antennas.
In a recent study published in Nature Communications, the Drexel-UBC team demonstrated how kirigami—a derivative of origami—can morph a single sheet of acetate coated with conductive MXene ink into a flexible 3D microwave antenna whose operational frequency can be altered simply by manipulating its shape—pulling or squeezing the design.
The importance of this proof of concept is highlighted by the researchers, as it introduces a novel, efficient, and cost-effective method for producing antennas. This is achieved by merely applying aqueous MXene ink onto a transparent elastic polymer substrate.
“For advancements in fields like soft robotics and aerospace, wireless technology requires antennas that can be easily fabricated and designed for tunable performance,” stated Yury Gogotsi, PhD, a distinguished professor within Drexel’s engineering college and a co-author of the research. “Kirigami naturally lends itself to a manufacturing process because complex 3D structures can be developed from a single 2D material with ease.”
Typically, microwave antennas are reconfigurable either through electronic means or by modifying their physical form. However, incorporating the circuitry needed for electronic adjustments can complicate the design, making the antenna bulkier and more prone to malfunction, as well as more costly to produce. In contrast, the process described in this study takes advantage of physical shape changes, enabling the creation of antennas in various intricate forms that are flexible, lightweight, and durable—qualities essential for use in movable robotic systems and aerospace applications.
To produce the experimental antennas, the researchers initially applied a specialized conductive ink, made of titanium carbide MXene, to an acetate sheet to create frequency-selective patterns. MXene ink is particularly advantageous in this context due to its chemical properties, which allow it to bond effectively to the substrate, resulting in a durable antenna that can be adjusted to modify its transmission characteristics.
MXenes, a category of two-dimensional nanomaterials discovered by Drexel researchers in 2011, possess physical and electrochemical traits that can be fine-tuned by slightly changing their chemical composition. Over the past decade, MXenes have found extensive application in areas requiring specific physiochemical behaviors, such as electromagnetic shielding, biofiltration, and energy storage. Their efficiency in transmitting radio waves has also made them a topic of interest for telecommunications.
Employing kirigami methods, which date back to 4th and 5th century Japan, the researchers made parallel incisions in the MXene-coated substrate. Pulling on the edges of the sheet caused an array of square-shaped resonator antennas to pop up from its flat surface. Adjusting the tension altered the angles of the array—this adaptability could be utilized for quickly tuning the antennas’ communication configurations.
The team constructed two arrays of kirigami antennas for testing, as well as a prototype of a co-planar resonator, a element used in sensors that generates waves of a specific frequency, to showcase their approach’s versatility. Beyond communication, the team suggests that these resonators and reconfigurable antennas could also be employed for strain sensing.
“Frequency selective surfaces, akin to these antennas, are structured to selectively transmit, reflect, or absorb electromagnetic waves at targeted frequencies,” explained Mohammad Zarifi, principal research chair and associate professor at UBC, who contributed to leading this research. “They feature active and/or passive structures and are commonly utilized in applications such as antennas, radomes, and reflectors to manage wave propagation in wireless communication, particularly for 5G and future technologies.”
The kirigami antennas demonstrated effective signal transmission across three popular microwave frequency bands: 2-4 GHz, 4-8 GHz, and 8-12 GHz. Moreover, the research team discovered that modifying the geometry and orientation of the substrate could redirect the waves emitted from each resonator.
The frequency generated by the resonator shifted by 400 MHz in response to deformations caused by strain, indicating its potential as a strain sensor for monitoring infrastructure and buildings.
The researchers believe these findings mark the initial steps toward integrating these components into relevant structures and wireless devices. Inspired by the diverse forms of kirigami, the team will pursue optimizing the antennas’ performance through exploring new shapes, substrates, and movements.
“Our aim was to enhance the tunability of antenna performance while simplifying the production process for new microwave components by merging a versatile MXene nanomaterial with kirigami-inspired designs,” stated Omid Niksan, PhD, from the University of British Columbia and a paper co-author. “The next phase of our research will investigate new materials and designs for antennas.”
