Electrode surface coating and method for manufacturing the same

Abstract

An electrode surface coating and method for manufacturing the electrode surface coating comprising a conductive substrate; and one or more surface coatings comprising one or more of the following metals titanium, niobium, tantalum, ruthenium, rhodium, iridium, palladium, or gold, or an alloy of two or more metals, or a combination of two or more alloys or metal layers thereof having an increase in the surface area of 5 times to 500 times of the corresponding surface area resulting from the basic geometric shape.

What I claim is:  
     
         1 . An electrode surface coating, comprising: 
 a conductive substrate; and    one or more surface coatings comprising one or more of the following metals titanium, niobium, tantalum, ruthenium, rhodium, iridium, palladium, or gold, or an alloy of two or more metals, or a combination of two or more alloys or metal layers thereof having an increase in the surface area of 5 times to 500 times of the corresponding surface area resulting from the basic geometric shape.    
     
     
         2 . The electrode surface coating of  claim 1  wherein said surface coating has a surface area of 50 times to 200 times the corresponding surface are resulting from the basic geometric shape.  
     
     
         3 . The electrode surface coating of  claim 1  wherein said surface coating has a thickness of 0.01 μm to 10 μm.  
     
     
         4 . The electrode surface coating of  claim 1  wherein said surface coating has a thickness of 0.1 μm to 5.0 μm.  
     
     
         5 . The electrode surface coating of  claim 1  wherein said surface coating has a thickness of 0.5 μm to 2.5 μm.  
     
     
         6 . The electrode surface coating of  claim 1  wherein said surface coating has an adhesive strength as measured by critical load greater than 35 mNs.  
     
     
         7 . The electrode surface coating of  claim 1  wherein said surface coating has a hemispherical configuration.  
     
     
         8 . The electrode surface coating of  claim 1  wherein said surface coating has a rough configuration having particles of a particle size of 0.01 μm to 3.0 μm.  
     
     
         9 . The electrode surface coating of  claim 1  wherein said surface coating has a rough configuration having particles of a particle size of 0.1 μm to 2.0 μm.  
     
     
         10 . The electrode surface coating of  claim 1  wherein said surface coating has a rough configuration having particles of a particle size of 0.5 μm to 1.0 μm.  
     
     
         11 . The electrode surface coating of  claim 1  wherein the relation of surface area to the thickness of said surface coating of 1.0 F/cm 3  to 6.0 F/cm 3 .  
     
     
         12 . The electrode surface coating of  claim 1  wherein the relation of surface area to the thickness of said surface coating of 1.8 F/cm 3  to 5.6 F/cm 3 .  
     
     
         13 . The electrode surface coating of  claim 1  wherein said conductive substrate comprises one or more of the following metals titanium, zirconium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, rhodium, iridium, nickel, palladium, platinum, silver, gold, or carbon.  
     
     
         14 . The electrode surface coating of  claim 1  wherein said conductive substrate comprises gold, platinum, platinum alloy, iridium, iridium oxide, rhodium, tantalum, titanium, titanium nitride or niobium.  
     
     
         15 . The electrode of  claim 1  wherein said surface coating is biocompatible.  
     
     
         16 . The electrode of  claim 12  wherein said surface coating does not contain lead.  
     
     
         17 . A method for electroplating an electrode surface coating having a rough surface, comprising: 
 electroplating the surface of a conductive substrate at a rate such that the metal particles form on the conductive substrate faster than necessary to form shiny platinum and slower than necessary to form platinum black.    
     
     
         18 . The method of  claim 17  wherein said step of electroplating is accomplished at a rate of more than 0.05 μm per minute, but less than 1 μm per minute.  
     
     
         19 . The method of  claim 17  wherein the electroplating process is controlled by electrode voltage.  
     
     
         20 . The method of  claim 19  wherein the voltage is constant voltage.  
     
     
         21 . The method of  claim 19  wherein the controlled voltage causes at least a partially diffusion-limited plating reaction.  
     
     
         22 . The method of  claim 17  wherein the electroplating is accomplished at a rate of more than 0.05 μm per minute, but less than 1 μm per minute.  
     
     
         23 . An electrode surface coating prepared by the method of  claim 17 .  
     
     
         24 . A method of using the electrode of  claim 1  for manufacturing a flexible stimulation device for a retina implant.  
     
     
         25 . A method of using the electrode of  claim 1  for manufacturing high density interconnects and flexible hybrid assemblies for active biomedical implants.  
     
     
         26 . A method of using the electrode of  claim 1  for manufacturing a thin-film multielectrode array for transmural cardiac recording.  
     
     
         27 . A method of using of a polymer layer of  claim 1  for manufacturing thin-film multielectrode arrays for a cochlear implant.