04/18/2015 at 14:40 •
Today the copper tape arrived. 30mm x 5m for about 17€. Not really cheap but this stuff hopefully allows for reliable contacting the foil. For those playing along: Look for copper tape with conductive glue! Anything else won't be of any help.
I fear the glue is going to be the weak spot of the construction. I will have to test how reliable and repeatable the electrical properties of such a joint are.
04/15/2015 at 06:07 •
While waiting for the real deal I tried some ESD-Packing materiels I had lying around. Turns out none of the clear foils and bubblewraps are of any use in this project. That was to be expected.
But I found a foam in a IC-packing that seems to be slightly pressure-sensitive. I have no Idea where this stuff came from nor where the ICs were bought. But of course I will follow that hint as well. But experience tells me foam won't be as reliable as foils as it will degrade over time.
My delivery is still on hold due to some parts which are not in stock yet. Meh. Need them for another project.
04/06/2015 at 09:02 •
The very first thing I ordered is CarboStat-Foil. This is carbon-fiber injected foil for ESD-Sensitive packing applications. Carbostat is volumina-conducting and tinkerers found out this stuff can be used for wearable gadgets. If you want to play along try linqstat / velostat as searchterms, tepending on where you live. It is this deep black ESD foil. Adafruit sells sheets of it which may be of interest for small sensors and applications. In Germany I *think* it is carbostat as a equivalent. You can get it in different sizes and thicknesses.
Next thing is copper tape with conductive glue for contacting the foil. This should allow to solder wires on. I would suggest some high quality stuff here for reliability.
I told you it was all of the shelf components, right?
Now, it will take me some time till the materials arrive. I will play around with different ESD-packing stuff I have lying around, but I don't think they will work. What makes those ***stat foils special is the infused carbon fibers.
04/05/2015 at 11:08 •
The hackaday prize is the perfect reason to get my idea off the ground. Just started with my project page here, all is new and I propably have to learn a lot. Any suggestions, corrections and comments are welcome!
Right now I started listing the needed materials and will be sourcing them after Easter. Should come in well below 100€ (EURO) for hopefully lots of sensors in all sizes and shapes.
If there is someone who wants to contribute: If I get my sensors up and running I for shure need someone to help extracting heart- and breathing-patterns from the gathered data to reach a proof of concept level.