CNT Yarn Capacitive Fabric Touch Sensor

DexMat carbon nanotube yarn is conductive, durable, flexible, and lightweight – so naturally, we are excited about its potential to be used in the emerging field of wearable electronics. Because our yarn can be handled like a textile thread, it can potentially be combined together with textile yarns to make clothing with complex electronic functionality without sacrificing comfort or weight. Additionally, because they have such a high surface area, our CNT yarns are excellent at interfacing electrically with the human body, whether that be through contact with body fluids or through “dry” contact with the skin. This means that they can potentially be used to make smart clothing that monitors the health of the wearer, or tracks movement and muscle contraction.

Capacitive touch sensing is a body-to-machine interfacing technology that is already in widespread use in the modern world, and which has a lot of potential in wearable technology – this type of device can be used to fabricate clothing with built-in buttons or even keyboards which operate with the touch of a finger. A basic description of capacitive touch sensing technology can be found here.

With the help of our friends at ZSK, we have made a capacitive touch sensor using DexMat CNT yarn. Check it out in the video below!

The demo consists of a patch of CNT yarn sewn into the backing fabric, with the tail end of that yarn connected to one of the input pins of an Arduino chip. The Arduino can be connected to a computer or other power source via a usb connection, and this connection provides that chip with a “ground” electrical voltage. Touching the CNT yarn with a fingertip shifts the voltage level of the connected input pin away from that ground level, and this triggers a pre-defined response (in this case, lighting up the Arduino LEDs and playing a sound). This works with a very light touch from the finger, and even works with just the single CNT yarn connecting the swatch to the chip – the additional surface area of the CNT yarn fabric patch wasn’t necessary for this particular case, but it also serves as a nice demonstration of how the yarn can be incorporated into a fabric!

The CNT yarn that was used to make this demo was our 200 micron HS yarn, but other yarn sizes should produce similar results. You can order CNT yarn and fiber in a variety of sizes from our online store at store.dexmat.com.

Space Elevator Kickstarter Project

One of our customers, Dr. Peter Renteln, has recently launched a Kickstarter campaign to fund experiments in methods of mechanically strengthening carbon nanotube yarns.  Dr. Renteln’s ultimate goal is to help bridge the gap between the current performance of carbon nanotube yarns and the type of performance that might one day make a Space Elevator project possible.

DexMat carbon nanotube braid was used for some of the initial testing in this project, and we are always interested to see if methods can be developed that will make our materials even stronger. We are excited to follow this project and see the outcome of these experiments!

You can read about and contribute to the Kickstarter project here.

Chopping Carbon Nanotube Yarn with an Axe (Part 2!)

Tyson took a trip to the Class Axe Throwing range in Dallas, TX recently, so it seemed like the perfect time to make a follow-up to the recent video in which we demonstrated our carbon nanotube yarn surviving an axe blow. In this new video, we see how well some of our yarns and films survive when an axe is thrown at them!

A big thank you to the folks at Class Axe Throwing for letting us perform this fun test at their range, and for helping us out with some of the throwing!

Carbon Nanotube AUX Cable

In this video, we demonstrate an auxiliary cable made with carbon nanotube (CNT) conductors and shielding. The cable has two CNT yarn conductors that are insulated with a nylon braid and then shielded with a CNT fiber braid. The sound quality is great and highlights the tremendous potential for CNT materials in high-end audio cables!

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!

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.

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.

Making Carbon Nanotube Yarns

This video shows how carbon nanotube (CNT) fibers can be assembled into yarns or ropes by plying the fibers together with a planetary ropemaking machine. These yarns are lightweight and highly flexible. They are also more conductive than stainless steel thread and much stronger than copper wire.

Will it Burn? CNT Yarn vs Stainless Steel Thread

This video highlights the high temperature stability of CNT yarns compared to stainless steel thread by applying a 1430 C butane torch to both materials. The stainless steel thread barely lasts 1 second before melting, while the CNT yarn survives the torch for more than 30 seconds without any visible damage.  The high thermal stability and superior thermal conductivity of the CNT material is most likely the reason that it is able to survive exposure to the flame from the torch.  The impressive thermal properties of CNT fibers and films make them highly promising for application in flame retardant materials such as those used in firefighter suits.

SBIR Funding Furthers DexMat CNT Technology

Source: Original article appears in the December 2018 issue of the Wire Journal International.
The feature on DexMat is on pages 48-50.