In selecting components for an EEG development kit, I'm wondering if certain types of electrodes capture signals better in the presence of (a small amount of) head hair?

For instance options include:

  • Gold and silver cup electrodes*
  • Spider electrodes**
  • Webb electrodes***
  • Flat electrodes

and many others. My intuition is that the Spider or Webb designs might be better because hair could go through the gaps, but that's just a guess.

*Cup electrodes (shown with Ten20 conductive paste):

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**Spider electrodes:

enter image description here

***Webb electrodes:

enter image description here

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    \$\begingroup\$ There also are scalp electrodes that look like a tiny hairbrush. Here's an example. (Haven't got first hand experience with those myself.) \$\endgroup\$ – Nick Alexeev Aug 20 '17 at 21:36
  • \$\begingroup\$ @NickAlexeev That's actually pretty brilliant \$\endgroup\$ – Hack-R Aug 20 '17 at 21:37

Actually the electrodes should be wrapped with some cloth that is wetted with the electrolyte. A common salt NaCl is an option, but professional electrodes use Ag salt. I guess the type of salt has to do with electrode material. The shape and all fancy stuff doesn't matter.

  • \$\begingroup\$ Thanks +1. Do you know if hair normally causes a big problem? Do you think the idea behind the different shapes is just comfort? Nothing really technical at all? Some of the claims on the websites like bio-medical.com say stuff like superior adhesion and covers a greater surface area. (that quote is from the Spider one). \$\endgroup\$ – Hack-R Aug 20 '17 at 20:29
  • \$\begingroup\$ Sorry, another follow up, are you sure about the cloth? This image from the OpenBCI project shows the gold cup electrodes with the Ten20 conductive paste directly on it and it didn't mention about the cloth in the Learning section: cdn.shopify.com/s/files/1/0613/9353/products/… \$\endgroup\$ – Hack-R Aug 20 '17 at 20:36
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    \$\begingroup\$ Not sure about the cloth, the technology is changing in years. A good contact with skull is made with the help of gel, electolyte, ...the electrode should not oxidise, or you want to srub the surface each time or use an electode that is just for one single use. \$\endgroup\$ – Marko Buršič Aug 20 '17 at 20:51

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