Attachment to fabric:
In this test, the conductive thread was sewn to fabric through the bobbin of a sewing machine. In our tests, we found the thread worked better through the bobbin than as a top thread. However, conductive thread comes in different weights and coarseness which may effect this.
In swatch 07, we sewed only once and the resistance was very high. In swatch 11, we sewed over the same line several times, to thicken the conductive line and reduce resistance.
Attachment between components:
In this test, we have a sewable vibration motor and a sewable coin cell holder. The components are sewn to the conductive line using additional conductive thread.
Detail images for Swatch 11, which used multiple lines of conductive thread sewn through the bobbin of a sewing machine:
Pros and Cons:
A benefit of using conductive thread in a sewing machine to make traces, is you have a lot of flexibility in terms of the trace pattern/shape. You could sew in a swirl, a zig-zag, or any other shape you might want.
Sewing the thread multiple times through a bobbin (swatch 11) resulted in a reliable trace test. A con is this is a labor intensive way to create a trace, and still slightly more resistant than using some of the conductive tapes or wire.
Finally, it’s a bit awkward to sew to the conductive thread trace with more thread to attach components. For best results you would leave extra thread at the end of your trace and use that to attach components.
Because conductive thread varies by manufacturer and type (ie 2, ply 4 ply) we highly recommend you make tests with this material before trying to use it in a project.
