Step 5OTHER SENSING IDEAS
Carbon Paint
One technique that produces some lovely results is the application of carbon paint to fabric. Depending on the thickness of the paint and the underlying fabric, one achieves different results. If the paint starts to crack too much, then when stretched the conductivity sinks, since there is simply just less physical connection. But if things come out just right and there is not too much cracking then the conductivity increases when stretched and we believe this is due to the fact that the carbon particles are being compressed though the physicality of the stretching and thus improving the conductive connection.
Conductive Textiles
The Berkley based company Eeonyx http://www.eeonyx.com/ produces some very interesting conductive textiles. They have the capability to coat almost any material/textile in a secret polymer solution, which can be regulated to produce any desired level of electrical conductivity/resistance. When they coat stretchy knits and materials such as Lycra and nylon, they practically produce stretch sensors. This is something we have just started to explore
Conductive Rubbers
There are lots of different conductive rubbers on the market and we have tested a few of them:
- Conductive rubber bands sold by All-Spec http://www.all-spec.com/1/viewitem/1862C/ALLSPEC/prodinfo/i=rss, also see: http://cnmat.berkeley.edu/resource/conductive_black_rubber_band
- Zoflex conductive rubber http://www.rfmicrolink.com/Conductive_rubber.html, also see: http://cnmat.berkeley.edu/resource/zoflex_conductive_rubber
- Conductive rubber ropes from Images Scientific Instruments http://www.imagesco.com/sensors/stretch-sensor.html
The problem we have had with using these rubbers as stretch sensors is that they are either very tough and take a lot of pull to really stretch and get a nice change in resistance, and as such would be hard to integrate in a motion capture suit, unless we make it super tight (or come up with other solutions). The other problem we encounter is that even though the change in resistance is measurable it bounces around a bit. It is often slow to react and then bounces to a peak before dropping down to a certain point, even though the rubber has only been stretches to a certain degree and held in the same position. These rubbers all react very nicely to pressure, when sandwiched between two conductive layers. They make great pressure sensors, replacing the layers of neoprene in that they offer their own natural force feedback and pressure distribution.
Stretching piece of Zoflex video >>
| « Previous Step | Download PDFView All Steps | Next Step » |
![]() |
Add Comment
|













































