Designing PCBs is interesting, but testing the materials for the EMG bracelet turned out to be no less interesting.

After googling similar devices and brainstorming all possible types of electrodes and connections, we decided to use a different approach - conductive fabrics, also known as “smart textiles”. We have been thinking about them for a long time and now decided to finally put them in practice. 

As soon as the New Year holiday hassle died down, I ordered all the necessary materials and moved on to the tests. The materials consisted of an elastic band, double-sided Velcro, conductive fabric tape, conductive thread, a needle and several metal buttons. While I waited for them, I sketched and cut out a paper mockup of the board.

I filmed the whole process, but since it lasted about an hour, I made a one-minute version.  

In short: I sewed the Velcro to the elastic band, glued conductive tape in the desired zones to serve as electrodes, and secured the zones with conductive thread that connected them to the button. Then I attached our uECG device to the buttons to check if there was a signal.  And… there indeed was a signal!

So we have successfully tested smart textiles - in the form of conductive fabric and thread - and embedded electrodes in a bracelet for uEMG! The next step is to make a fully working bracelet and test the signal on a new board...