Tag Archives: kirigami (folding and cutting paper)

Ancient 3D paper art (kirigami) and modern wireless technology

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The first nanokirigami (or nano-kirigami) story featured here was in a January 29, 2019 posting (Manipulating light at the nanoscale with kirigami-inspired technique). This latest story features a two-dimensional material and the kirigami technique, also, some researchers from the University of British Columbia (Canada).

An October 14, 2024 news item on ScienceDaily announces that the newly applied (ancient) technique could change wireless technology,

The future of wireless technology — from charging devices to boosting communication signals — relies on the antennas that transmit electromagnetic waves becoming increasingly versatile, durable and easy to manufacture. Researchers at Drexel University [Pennsylvania, US] and the University of British Columbia [UBC; Canada] believe kirigami, the ancient Japanese art of cutting and folding paper to create intricate three-dimensional designs, could provide a model for manufacturing the next generation of antennas.

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An October 14, 2024 Drexel University news release (also on EurekAlert), which originated the news item, provides more information (Note: Links have been removed),

Recently published in the journal Nature Communications, research from the Drexel-UBC team showed how kirigami — a variation of origami — can transform a single sheet of acetate coated with conductive MXene ink into a flexible 3D microwave antenna whose transmission frequency can be adjusted simply by pulling or squeezing to slightly shift its shape.

The proof of concept is significant, according to the researchers, because it represents a new way to quickly and cost-effectively manufacture an antenna by simply coating aqueous MXene ink onto a clear elastic polymer substrate material.

“For wireless technology to support advancements in fields like soft robotics and aerospace, antennas need to be designed for tunable performance and with ease of fabrication,” said Yury Gogotsi, PhD, Distinguished University and Bach Professor in Drexel’s College of Engineering, and a co-author of  the research. “Kirigami is a natural model for a manufacturing process, due to the simplicity with which complex 3D forms can be created from a single 2D piece of material.”

Standard microwave antennas can be reconfigured either electronically or by altering their physical shape. However, adding the necessary circuitry to control an antenna electronically can increase its complexity, making the antenna bulkier, more vulnerable to malfunction and more expensive to manufacture. By contrast, the process demonstrated in this joint work leverages physical shape change and can create antennas in a variety of intricate shapes and forms. These antennas are flexible, lightweight and durable, which are crucial factors for their survivability on movable robotics and aerospace components.

To create the test antennas, the researchers first coated a sheet of acetate with a special conductive ink, composed of a titanium carbide MXene, to create frequency-selective patterns. MXene ink is particularly useful in this application because its chemical composition allows it to adhere strongly to the substrate for a durable antenna and can be adjusted to reconfigure the transmission specifications of the antenna.

MXenes are a family of two-dimensional nanomaterials discovered by Drexel researchers in 2011 whose physical and electrochemical properties can be adjusted by slightly altering their chemical composition. MXenes have been widely used in the last decade for applications that require materials with precise physiochemical behavior, such as electromagnetic shielding, biofiltration and energy storage. They have also been explored for telecommunications applications for many years due to their efficiency in transmitting radio waves and their ability to be adjusted to selectively block and allow transmission of electromagnetic waves.

Using kirigami techniques, originally developed in Japan the 4th and 5th centuries A.D., the researchers made a series of parallel cuts in the MXene-coated surface. Pulling at the edges of the sheet triggered an array of square-shaped resonator antennas to spring from its two-dimensional surface. Varying the tension caused the angle of the array to shift — a capability that could be deployed to quickly adjust the communications configuration of the antennas. 

The researchers assembled two kirigami antenna arrays for testing. They also created a prototype of a co-planar resonator — a component used in sensors that naturally produces waves of a certain frequency — to showcase the versatility of the approach. In addition to communication applications, resonators and reconfigurable antennas could also be used for strain-sensing, according to the team.

“Frequency selective surfaces, like these antennas, are periodic structures that selectively transmit, reflect, or absorb electromagnetic waves at specific frequencies,” said Mohammad Zarifi, principal research chair, an associate professor at UBC, who helped  lead the research. “They have active and/or passive structures and are commonly used in applications such as antennas, radomes, and reflectors to control wave propagation direction in wireless communication at 5G and beyond platforms.”

The kirigami antennas proved effective at transmitting signals in three commonly used microwave frequency bands: 2-4 GHz, 4-8 GHz and 8-12 GHz. Additionally, the team found that shifting the geometry and direction of the substrate could redirect the waves from each resonator.

The frequency produced by the resonator shifted by 400 MHz as its shape was deformed under strain conditions – demonstrating that it could perform effectively as a strain sensor for monitoring the condition of infrastructure and buildings.

According to the team, these findings are the first step toward integrating the components on relevant structures and wireless devices. With kirigami’s myriad forms as their inspiration, the team will now seek to optimize the performance of the antennas by exploring new shapes, substrates and movements.

 “Our goal here was to simultaneously improve the adjustability of antenna performance as well as create a simple manufacturing process for new microwave components by incorporating a versatile MXene nanomaterial with kirigami-inspired designs,” said Omid Niksan, PhD, from [the] University of British Columbia, who was an author of the paper. “The next phase of this research will explore new materials and geometries for the antennas.”

Here’s a link to and a citation for the paper,

MXene-based kirigami designs: showcasing reconfigurable frequency selectivity in microwave regime by Omid Niksan, Lingyi Bi, Yury Gogotsi & Mohammad H. Zarifi. Nature Communications volume 15, Article number: 7793 (2024) DOI: https://doi.org/10.1038/s41467-024-51853-1 Published: 06 September 2024

This paper is open access.

Manipulating light at the nanoscale with kiragami-inspired technique

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At left, different patterns of slices through a thin metal foil, are made by a focused ion beam. These patterns cause the metal to fold up into predetermined shapes, which can be used for such purposes as modifying a beam of light. Courtesy of the researchers

Nanokiragami (or nano-kiragami) is a fully fledged field of research? That was news to me as was much else in a July 6, 2018 news item on ScienceDaily,

Nanokirigami has taken off as a field of research in the last few years; the approach is based on the ancient arts of origami (making 3-D shapes by folding paper) and kirigami (which allows cutting as well as folding) but applied to flat materials at the nanoscale, measured in billionths of a meter.

Now, researchers at MIT [Massachusetts Institute of Technology] and in China have for the first time applied this approach to the creation of nanodevices to manipulate light, potentially opening up new possibilities for research and, ultimately, the creation of new light-based communications, detection, or computational devices.

A July 6, 2018 MIT news release (also on EurekAlert), which originated the news item, adds detail,

The findings are described today [July 6, 2018] in the journal Science Advances, in a paper by MIT professor of mechanical engineering Nicholas X Fang and five others. Using methods based on standard microchip manufacturing technology, Fang and his team used a focused ion beam to make a precise pattern of slits in a metal foil just a few tens of nanometers thick. The process causes the foil to bend and twist itself into a complex three-dimensional shape capable of selectively filtering out light with a particular polarization.

Previous attempts to create functional kirigami devices have used more complicated fabrication methods that require a series of folding steps and have been primarily aimed at mechanical rather than optical functions, Fang says. The new nanodevices, by contrast, can be formed in a single folding step and could be used to perform a number of different optical functions.

For these initial proof-of-concept devices, the team produced a nanomechanical equivalent of specialized dichroic filters that can filter out circularly polarized light that is either “right-handed” or “left-handed.” To do so, they created a pattern just a few hundred nanometers across in the thin metal foil; the result resembles pinwheel blades, with a twist in one direction that selects the corresponding twist of light.

The twisting and bending of the foil happens because of stresses introduced by the same ion beam that slices through the metal. When using ion beams with low dosages, many vacancies are created, and some of the ions end up lodged in the crystal lattice of the metal, pushing the lattice out of shape and creating strong stresses that induce the bending.

“We cut the material with an ion beam instead of scissors, by writing the focused ion beam across this metal sheet with a prescribed pattern,” Fang says. “So you end up with this metal ribbon that is wrinkling up” in the precisely planned pattern.

“It’s a very nice connection of the two fields, mechanics and optics,” Fang says. The team used helical patterns to separate out the clockwise and counterclockwise polarized portions of a light beam, which may represent “a brand new direction” for nanokirigami research, he says.

The technique is straightforward enough that, with the equations the team developed, researchers should now be able to calculate backward from a desired set of optical characteristics and produce the needed pattern of slits and folds to produce just that effect, Fang says.

“It allows a prediction based on optical functionalities” to create patterns that achieve the desired result, he adds. “Previously, people were always trying to cut by intuition” to create kirigami patterns for a particular desired outcome.

The research is still at an early stage, Fang points out, so more research will be needed on possible applications. But these devices are orders of magnitude smaller than conventional counterparts that perform the same optical functions, so these advances could lead to more complex optical chips for sensing, computation, or communications systems or biomedical devices, the team says.

For example, Fang says, devices to measure glucose levels often use measurements of light polarity, because glucose molecules exist in both right- and left-handed forms which interact differently with light. “When you pass light through the solution, you can see the concentration of one version of the molecule, as opposed to the mixture of both,” Fang explains, and this method could allow for much smaller, more efficient detectors.

Circular polarization is also a method used to allow multiple laser beams to travel through a fiber-optic cable without interfering with each other. “People have been looking for such a system for laser optical communications systems” to separate the beams in devices called optical isolaters, Fang says. “We have shown that it’s possible to make them in nanometer sizes.”

The team also included MIT graduate student Huifeng Du; Zhiguang Liu, Jiafang Li (project supervisor), and Ling Lu at the Chinese Academy of Sciences in Beijing; and Zhi-Yuan Li at the South China University of Technology. The work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, and the U.S Air Force Office of Scientific Research.

The researchers have also provided some GIFs,

And,

Here’s a link to and a citation for the paper,

Nano-kirigami with giant optical chirality by Zhiguang Liu, Huifeng Du, Jiafang Li, Ling Lu, Zhi-Yuan Li, and Nicholas X. Fang. Science Advances 06 Jul 2018: Vol. 4, no. 7, eaat4436 DOI: 10.1126/sciadv.aat4436

This paper is open access.