Chopping Carbon Nanotube Yarn with an Axe

Some time ago, we uploaded a video showing how well a sample of our carbon nanotube film was able to hold up to an impact from a blade. In this video, we take things a step further by trying to cut some of our carbon nanotube yarn with an axe!

Spoiler warning: it survives better than that piece of wood does.

Flexible CNT Antennas from Rice U

Antennas of flexible nanotube films an alternative for electronics

HOUSTON – (June 10, 2019) – Antennas made of carbon nanotube films are just as efficient as copper for wireless applications, according to researchers at Rice University’s Brown School of Engineering. They’re also tougher, more flexible and can essentially be painted onto devices.

The Rice lab of chemical and biomolecular engineer Matteo Pasquali tested antennas made of “shear-aligned” nanotube films. The researchers discovered that not only were the conductive films able to match the performance of commonly used copper films, they could also be made thinner to better handle higher frequencies.

Metal-free antennas made of thin, strong, flexible carbon nanotube films are as efficient as common copper antennas, according to a new study by Rice University researchers. (Credit: Jeff Fitlow/Rice University)

Metal-free antennas made of thin, strong, flexible carbon nanotube films are as efficient as common copper antennas, according to a new study by Rice University researchers. (Credit: Jeff Fitlow/Rice University)

The results detailed in Applied Physics Letters advance the lab’s previous work on antennas based on carbon nanotube fibers.

The lab’s shear-aligned antennas were tested at the National Institute of Standards and Technology (NIST) facility in Boulder, Colorado, by lead author Amram Bengio, who carried out the research and wrote the paper while earning his doctorate in Pasquali’s lab. Bengio has since founded a company to further develop the material.

At the target frequencies of 5, 10 and 14 gigahertz, the antennas easily held their own with their metal counterparts, he said. “We were going up to frequencies that aren’t even used in Wi-Fi and Bluetooth networks today, but will be used in the upcoming 5G generation of antennas,” he said.

Bengio noted other researchers have argued nanotube-based antennas and their inherent properties have kept them from adhering to the “classical relationship between radiation efficiency and frequency,” but the Rice experiments with more refined films have proved them wrong, allowing for the one-to-one comparisons.

To make the films, the Rice lab dissolved nanotubes, most of them single-walled and up to 8 microns long, in an acid-based solution. When spread onto a surface, the shear force produced prompts the nanotubes to self-align, a phenomenon the Pasquali lab has applied in other studies.

Bengio said that although gas-phase deposition is widely employed as a batch process for trace deposition of metals, the fluid-phase processing method lends itself to more scalable, continuous antenna manufacturing.

The test films were about the size of a glass slide, and between 1 and 7 microns thick. The nanotubes are held together by strongly attractive van der Waals forces, which gives the material mechanical properties far better than those of copper.

The researchers said the new antennas could be suitable for 5G networks but also for aircraft, especially unmanned aerial vehicles, for which weight is a consideration; as wireless telemetry portals for downhole oil and gas exploration; and for future “internet of things” applications.

Rice University alumnus Amram Bengio holds a flexible nanotube film antenna. The antenna, which has proven as efficient as those made of copper wire, can essentially be painted onto devices. (Credit: Jeff Fitlow/Rice University)
Rice University alumnus Amram Bengio holds a flexible nanotube film antenna. The antenna, which has proven as efficient as those made of copper wire, can essentially be painted onto devices. (Credit: Jeff Fitlow/Rice University)

“There are limits because of the physics of how an electromagnetic wave propagates through space,” Bengio said. “We’re not changing anything in that regard. What we are changing is the fact that the material from which all these antennas will be made is substantially lighter, stronger and more resistant to a wider variety of adverse environmental conditions than copper.”

“This is a great example of how collaboration with national labs greatly expands the reach of university groups,” Pasquali said. “We could never have done this work without the intellectual involvement and experimental capabilities of the NIST team.”

Co-authors of the paper are Rice graduate student Lauren Taylor, research group manager Robert Headrick and alumni Michael King and Peiyu Chen; Damir Senic, Charles Little, John Ladbury, Christian Long, Christopher Holloway, Nathan Orloff and James Booth, all of NIST; and former Rice faculty member Aydin Babakhani, now an associate profess or of electrical and computer engineering at UCLA. Pasquali is the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, professor of chemistry and of materials science and nanoengineering. Bengio is the founder and chief operating officer of Wootz, L.L.C.

The Air Force Office of Scientific Research, the Department of Defense and a National Defense Science and Engineering Graduate Fellowship supported the research.

 

Source: Rice University News & Media

New High Strength Yarn Product Release

In this video we introduce a high strength grade of 200 micron diameter CNT yarn to the catalog of DexMat yarn products! The high strength yarn has a breaking force of well over 3 kg and is about 50 % stronger than its predecessor. The tensile strength of this yarn is 1 GPa, and it is also very lightweight and highly flexible. Our high strength yarn is now available for purchase at the DexMat online store.

New Carbon Nanotube Film Product Release

In this video we introduce 10 micron thick film to the catalog of DexMat film products and show how the film can be easily processed on standard winding equipment. CNT films have tremendous potential in applications ranging from EMI shielding in cables/electronics, to thermal interface materials, to heating elements or conductive materials in clothing or e-textiles. High conductivity, high strength, 10 micron thick film is now available for purchase at the DexMat online store!

Happy Pi Day!

Here we show off the difference between Pi grams of copper wire and Pi grams of our carbon nanotube yarn.

Full disclosure: some of the difference in length here is due to the carbon nanotube yarn being thinner. The copper wire in this video is 1.2 mm in diameter; the carbon nanotube yarn ranged from 0.7 mm to 1 mm in diameter. The length difference is so extreme, however, because of the difference in density between the two materials, which is close to a factor of 9.

Happy Pi Day!

Plating Carbon Nanotube Yarn with Copper

In this video we provide a brief look at some of the experimental work we are doing to develop new products at DexMat. Here, we are using an electroplating process to coat our carbon nanotube yarn with a layer of copper. This process may allow us to create a useful hybrid material, combining the conductivity of metallic copper with the strength and durability of our lightweight carbon nanotube yarn.

Braiding CNT Fibers

In this video, we demonstrate the process that we use for braiding carbon nanotube fibers to make EMI shielding braids or braided CNT yarns. These braids are lightweight and highly flexible. They are also more conductive than stainless steel fiber braids and much stronger than copper wire.

CNT Yarn & Tape: Resistance Measurement

A demonstration of the methods & tools we typically use to measure the electrical resistance of our carbon nanotube yarns & tapes.

CNT tape EMI shield: blocking phone reception!

In this video we use a quick and easy experiment to demonstrate that our 5 cm wide carbon nanotube tape is able to effectively block cell phone signals. We have wrapped Tyson’s phone in 2 layers of this tape, which effectively blocks incoming calls due to the tape’s excellent electromagnetic shielding properties.

Carbon Nanotube Tapes up to 5 cm wide!

This video demonstrates the array of carbon nanotube tapes that DexMat currently produces. Strong, conductive, and flexible tapes or films up to 5 cm wide are currently available and even wider tape formats are currently under development.

These tapes have tremendous potential in applications ranging from EMI shielding in cables/electronics, to thermal interface materials, to heating elements or conductive materials in clothing or e-textiles.