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.

Wearable Electronics: Carbon Nanotube Yarn + LEDs

This is the follow-up to our previous video, in which we demonstrated how our carbon nanotube yarn could be stitched into fabric using a conventional sewing machine. Here we are showing off the finished product: a DexMat t-shirt with blinking LEDs embedded into our lightning bolt logo!

We used an Arduino Gemma and a small battery pack (sewn into a pouch near the hem of the shirt) to create this LED effect. The electrical connections between the Arduino and the LEDs consist of 4 lengths of our high strength 130 micron carbon nanotube yarn. As Tyson demonstrates, this yarn can easily bend and fold with the shirt, and the zig-zag stitch allows it to stretch as well. It’s also extremely light and comfortable!

Check out the first part of this project here.

DexMat Carbon Nanotube Yarn + Sewing Machine

Here we show the first part of the process of making a simple wearable electronic display in a t-shirt using our carbon nanotube yarn. We use a standard sewing machine to stitch several long filaments of our yarn into the shirt; we plan to eventually connect these to a battery, an Arduino, and some LEDs.

The CNT yarn is strong enough and flexible enough to be run through the sewing machine without being damaged, but it is somewhat less flexible, and much less stretchable, than cotton yarn; as a result we did have some trouble, as you can see in this video. In the end, the carbon nanotube yarn worked well when it was fed from the bottom bobbin. It worked well when fed from the top bobbin and stitched into thick fabric, but not so well with the more elastic t-shirt fabric.

Complications aside, this video demonstrates the potential of our carbon nanotube fibers and yarns for use in e-textiles. It is possible that with more time and knowledge we may have been able to troubleshoot the problem…if you are a wearable electronics maker, why not get some of our yarn and see if you are able to make it work? 🙂

Update: check out our video of the completed shirt here!

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

Carbon Nanotube Yoyo

We are still working on the sewing machine video that we promised last week, but in the meantime, we wanted to put together a fun demonstration of the flexibility of our carbon nanotube yarn. Here we have replaced the cotton string on a yoyo with a length of our carbon nanotube yarn. The yarn is flexible enough for the yoyo to work perfectly, and as you can see it is strong enough for Dmitri to perform a few tricks.

High strength 130 micron CNT yarn spotlight

In this video we focus on one of our newly available products, a higher strength version of our 130 micron diameter carbon nanotube yarn.

DexMat at Interwire 2019

DexMat is at the Interwire 2019 expo in Atlanta, GA, to talk about our carbon nanotube yarns and films. If you are in the area from May 14 – May 16, come by booth 154 and say hello!

CNT Film Impact Test

In this video we perform an “amateur” impact test on a sample of our carbon nanotube film by striking a razor blade into it with a hammer. The CNT film is compressed, but not torn or damaged.

See DexMat at Interwire 2019

Come and meet DexMat at the Interwire Trade Exposition in Atlanta, GA from May 14th through May 16th!
We will be showing off examples of our Carbon Nanotube wires and films.

Learn more about Interwire at
 https://www.interwire19.com/

Failure Current of DexMat CNT Yarn

In this video we demonstrate the amount of electric current that our 500 micron diameter CNT yarn can sustain in air, and compare this to a copper wire measured with the same apparatus and environment. Here are the precise properties of the materials used in these tests:

The CNT yarn has an average diameter of 500 microns, a linear mass of 0.18 mg/m, and a linear resistance of 1.3 Ohms/m.

The copper wire is a 36 gauge wire with a diameter of 127 microns, a linear mass of 0.26 mg/m, and a linear resistance of 0.59 Ohms/m.

Note that the voltage measurements shown on the power supply display represent the voltage drop through the entire circuit, not only across the sample being measured.