Dry electrodes
Dry electrodes are electrodes for attachment to human skin without skin preparation or the use of electrolyte gels. The electrode includes a substrate, electrically conductive particles with at least one point, in contact with the substrate, a supporting layer that envelopes the electrically conductive particles with points that protrude from the supporting layer, and an electrical connector. Some electrodes have an electrically conductive substrate, other electrodes have an electrically conductive supporting layer.
1. An electrode comprising:
an electrically conductive substrate with a first major surface and a second major surface;
a discontinuous layer of electrically conductive particles wherein at least some of the electrically conductive particles are in contact with the second major surface of the conductive substrate, wherein the electrically conductive particles comprise shaped particles with at least one point for penetrating the stratum corneum and epidermis layers of skin, and wherein the electrically conductive particles comprise ceramic particles including a conductive coating;
a supporting layer with a first major surface and a second major surface, where the first major surface of the supporting layer is in contact with the second major surface of the electrically conductive substrate and the supporting layer envelopes the electrically conductive particles such that the at least one point of at least one of the electrically conductive particles protrudes from the second major surface of the supporting layer; and
an electrical connector in electrical contact with the second major surface of the electrically conductive substrate, and protruding from the electrically conductive substrate.
2. The electrode of claim 1 , wherein the electrically conductive particles comprise non-compressive shaped particles wherein at least one dimension of the shaped particles is 175-1,500 micrometers.
3. The electrode of claim 1 , wherein the supporting layer comprises a layer of pressure sensitive adhesive.
4. The electrode of claim 1 , wherein the supporting layer comprises a transfer tape, wherein the transfer tape comprises a three-layer construction comprising a first pressure sensitive adhesive layer, a second pressure sensitive adhesive layer, and a layer between the first pressure sensitive adhesive layer and the second pressure adhesive layer.
5. The electrode of claim 1 , wherein the at least point of the shaped particles protrudes from the first major surface of the supporting layer by 50-1,000 micrometers.
6. The electrode of claim 1 , wherein the conductive coating is a first conductive coating, and wherein the electrically conductive particles further comprise a second conductive coating.
7. The electrode of claim 6 , wherein the second conductive coating covers only a portion of the first conductive coating.
8. The electrode of claim 1 , wherein the support layer comprises a first layer, a second layer layered onto the first layer, and a third layer layered onto the second layer.
9. The electrode of claim 8 , wherein the first layer and third layer comprise adhesive layers, and wherein the second layer comprises a film layer.
10. The electrode of claim 1 , wherein the electrically conductive substrate comprises a conductive layer and a polymeric film layer.
11. The electrode of claim 1 , wherein the electrode lacks an electrolyte gel.
12. The electrode of claim 7 , wherein the second conductive coating covers the at least one point for penetrating the stratum corneum and epidermis layer of skin.