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.