This is a placeholder topic for “EeonTex Pressure Sensing Fabric” comments.
This EeonTex fabric is a conductive, nonwoven microfiber with piezo-resistive functionality for use in dynamic sensors to map and measure pressure, bend, angle stretch …Read more
I would like to know it works inside the product, why when we bend it there is a variation of resistance ?
That’s an excellent question, essentially, it’s due to the material it’s made of. There’s three distinct kinds of material when it comes to electrical properties. In summary, there’s insulators, which resist the flow of current, conductors, which only slightly resist the flow of current, and semi-conductors, which do a little bit of both depending on the conditions they’re exposed to. Essentially, as the amount of tensile load increases on this fabric, it slightly changes in resistance, this is due to both the length of the path changing, and the material properties of the polymer the fabric has been coated in. You may be interested in the video below on this topic.
Another interesting material us older guys may remember is carbon. Resistance changes under pressure. More pressure less resistance. That is how the old carbon microphones (Telephones etc) worked. The resistance changed under the influence of sound pressure
If anyone has ever dismantled an old sewing machine speed controller would notice (I did once and had hundreds of thin carbon discs everywhere) lots of thin carbon discs about 20mm dia stacked in a pile. Pressure on the pedal increased pressure on the pile. Connected as a rheostat in series with the motor thus controlling speed. Simple but effective.
I once saw in a workshop a lab type instrument which was a rheostat based on this principle. Quite large physically but would probably handle a bit of power. I think the main advantage of this type of instrument would be the almost zero inductance compared to a wire wound type (bifilar wound or not). Never saw it used in anger.
What is the material of the fabric ? Do you think that I can buy a little part of the fabric? I am a student in the university and I would like to study the fabric for a work
As listed on the product page it’s a 70/30 percent blend of Polyester/Nylon. I’d recommend just placing an order through the site - it’s in stock at the moment so will be able to dispatch quickly (ie. Monday, since it’s already fairly late on a Friday).
I would like to know if it is possible to send it in France as I live in France and on the website there is only Australia or New Zealand.
We’re only able to ship to Australia and New Zealand at this time. However, you may be able to obtain it from Sparkfun directly:
Treck masters is looking for a very small sensor to work with our Luggage Security System to monitor any movement of the zipper and zipper slide if being forced open. Do you have any products that can be modified to do this type of sensoring?
We are investigating have a sensor on each side of the zipper slider if small enough or one at each end of the zipper.
Hi Leslie, Welcome to the forum,
That’s a tricky design problem. While you could measure the fabric to detect stretching and pulling it would be very difficult to screen out false positives such as a bag being jostled about or overfilled.
If you are looking to design a commercial product with a patent then it may be best to engage with an engineering consultancy, we often recommend SAPHI for commercialization of similar projects.
Are you looking to monitor the full length of the zipper tape itself, or just the zipper slider itself?