Use Vaseline as a resist and a bath of salt and vinegar to etch away the copper from copper fabric to make circuits and sensors.
More pictures on Flickr:
>> http://www.flickr.com/photos/plusea/sets/72157623861855224/
Inspired by instructions from Rehmi Post and Kit Waal.
Also see Sew-through Soft Circuits post by Meredith Scheff on The Steampunk Workshop:
>> http://steampunkworkshop.com/sew-through-soft-circuits
Tested etching mix:
* 100ml vinegar
* 7ml salt
Tested fabrics:
* FlecTron copper fabric etches very well because it is not coated with tarnishproof coating
* Cobaltex conductive fabric etched also
Insert piece of copper fabric. With resist applied to the areas taht you do not wish to etch away the copper from. See bellow list of resist media. For copper fabric we have been using pure copper polyester tefta fabric sold by LessEMF.
It takes up to 12 hours for the first piece of fabric to etch, but after that the following pieces take roughly 2 hours.
In the above examples the resisting medium (Vaseline) was only applied to one side of the fabric. Even though the Vaseline penetrates the fabric it does not protect the reverse side from etching. As can be seen in the following image.
Resist on both sides
If you want to preserve more of the copper you can apply Vaseline (or another medium of resist) to both sides of the copper fabric. The following photos show an example of this.
Images taken with USB microscope:
Mediums tested for resist against etching:
*Vaseline – great! (and you can iron off Vaseline into a paper towel)
*paper stickers – good, but they leave stickiness behind
*masking tape – good, but takes off some of the copper
*drawing with wax from candle – good, but have to scrape or iron off wax afterward
*duct tape – okay, but takes off a lot of copper with it
*stickytape – okay, but takes off a lot of copper with it
*hot glue – okay, but takes off a lot of copper with it
*fusible interfacing – works, but hard to get off afterward
*melted candle wax – doesn’t work great
More…
Instructable >> http://www.instructables.com/id/SIVDXXIFCEIJAZ3/
Syuzi >> http://www.diynetwork.com/diy/cda/article_print/0,1983,DIY_13721_5708736_ARTICLE-DETAIL-PRINT,00.html
[…] talk2myShirt occasional reminders and re-posting about new items which completely amaze me like the fabric PCB etching by using a solution of vinegar and salt and Vaseline as […]
[…] Perner-Wilson and her colleagues in the High-Low Tech group at MIT have been experimenting with circuit board etching of copper fabric using only salt and vinegar! Vaseline is used as the […]
How effective is this technique on regular non-fabric PCBs?
[…] Perner-Wilson and her colleagues in the High-Low Tech group at MIT have been experimenting with circuit board etching of copper fabric using only salt and vinegar! Vaseline is used as the […]
I’m with Cyrano- Anyone try this with a normal FR4 PCB? (It may take more vinegar)
If so, Vaseline mixed with some dark powder could be painted on with a fine tip paintbrush.
Anyone?
[…] 10. Follow instruction on Salt and Vinergar etching by HOW TO GET WHAT YOU WANT […]
Follow up to curious:
Can’t imagine why it won’t.(That’s speculation of course) I’ve been bugging myself to try Coke as an etchant. Might be safer than the stuff commonly used in pcb making, provided you don’t drink the used etchant, of course.
Cola contains phosphoric acid or citric acid depending on where you live. Pure citric acid is actually easy to come by (look for it in asian stores, health food shops, brewing suppliers). Like vinegar, it’s a weak acid – but I found it to dissolve egg shells faster than vinegar. That may have been down to the concentration though. I do wonder if it would work instead of vinegar for etching as vinegar typically comes pre-diluted whereas citric acid is typically sold as a white crystalline powder.
[…] A reader sent me a link and a tip that adding salt, (standard NaCl) to the mix along with heat will improve the etching speed and quality. I have not tested this to see how well it works or what quantities of salt and heat are optimal, but it sounds interesting. http://www.kobakant.at/DIY/?p=2575 […]