| Platinum surface coating and method for manufacturing the same -> Monitor Keywords |
|
|
 
Platinum surface coating and method for manufacturing the sameRelated Patent Categories: Stock Material Or Miscellaneous Articles, All Metal Or With Adjacent Metals, Composite; I.e., Plural, Adjacent, Spatially Distinct Metal Components (e.g., Layers, Joint, Etc.), Transition Metal-base Component, Group Viii Or Ib Metal-base Component, Platinum Group Metal-base ComponentPlatinum surface coating and method for manufacturing the same description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20050271895, Platinum surface coating and method for manufacturing the same. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of application Ser. No.: 10/226,976, filed Aug. 23, 2002, which claims the benefit of U.S. Provisional Application No. 60/372,062, filed Apr. 11, 2002, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The field of the invention relates to platinum surface coating and electroplating processes for deposition of platinum. [0005] 2. Description of Related Art [0006] Platinum has often been used as a material for electrodes in corrosive environments such as the human body due to its superior electrical characteristics, biocompatibility and stability. Platinum has many desirable qualities for use as an electrode for electrical stimulation of body tissue. Since platinum has a smooth surface and its surface area is limited by the geometry of the electrode, it is not efficient for transferring electrical charge. The platinum with a smooth surface is hereinafter called "shiny platinum". [0007] Electrodes for stimulating body tissue by electrical stimulation are known in great variety. For the utility of an implantable stimulation or sensing electrode--especially one intended for long-term use in a tissue stimulator with a non-renewable energy source and that, therefore, must require minimal energy--a high electrode capacitance and correspondingly low electrical impedance is of great importance. Furthermore, without sufficiently low impedance, a large voltage may cause polarization of both the electrode and the tissue to which the electrode is attached forming possibly harmful byproducts, degrading the electrode and damaging the tissue. [0008] Because the ability of an electrode to transfer current is proportional to the surface area of the electrode and because small electrodes are necessary to create a precise signal to stimulate a single nerve or small group of nerves, many in the art have attempted to improve the ability of an electrode to transfer charge by increasing the surface area of the electrode without increasing the size of the electrode. [0009] One approach to increase the surface area of a platinum electrode without increasing the electrode size and therefore to improve the ability of the electrode to transfer charge is to electroplate platinum rapidly such that the platinum molecules do not have time to arrange into a smooth, shiny surface. The rapid electroplating forms a platinum surface which is commonly known as "platinum black". Platinum black has a porous and rough surface which is less dense and less reflective than shiny platinum. U.S. Pat. No. 4,240,878 to Carter describes a method of plating platinum black on tantalum. [0010] Platinum black is more porous and less dense than shiny platinum. Platinum black has weak structural and physical strength and is therefore not suitable for applications where the electrode is subject to even minimal physical stresses. Platinum black also requires additives such as lead to promote rapid plating. Lead, however, is a neurotoxin and cannot be used in biological systems. Finally, due to platinum black's weak structure, the plating thickness is quite limited. Thick layers of platinum black simply fall apart. [0011] For the foregoing reasons there is a need for an improved platinum surface coating and process for electroplating the surface to obtain an increased surface area for a given geometry and at the same time the coating is structurally strong enough to be used in applications where the platinum surface coating is subject to physical stresses. BRIEF SUMMARY OF INVENTION [0012] The present invention is directed in part to a platinum surface coating having increased surface area for greater ability to transfer charge and also having sufficient physical and structural strength to withstand physical stress. [0013] This and other aspects of the present invention which may become obvious to those skilled in the art through the following description of the invention are achieved by an improved platinum surface coating and method for preparing the improved platinum surface coating having a fractal surface coating of platinum, hereinafter called "platinum gray". Platinum gray has an increase in surface area of at least 5 times compared to shiny platinum of the same geometry. Platinum gray has at the same time an improved resistance to physical stress when compared to platinum black. The gray color is not considered a feature of the invention. It is a means of describing the invention. The process of electroplating the surface coating of platinum gray comprising plating at a moderate rate, i.e., at a rate that is faster than the rate necessary to produce shiny platinum and that is less than the rate necessary to produce platinum black. BRIEF DESCRIPTION OF DRAWINGS [0014] FIG. 1 shows a platinum gray surface magnified 2000 times. [0015] FIG. 2 shows a shiny platinum surface magnified 2000 times. [0016] FIG. 3 shows a platinum black surface magnified 2000 times. [0017] FIG. 4 shows color density (D) values and lightness (l*) values for several representative samples of platinum gray, platinum black and shiny platinum. [0018] FIG. 5 shows a three-electrode electroplating cell with a magnetic stirrer. [0019] FIG. 6 shows a three-electrode electroplating cell in an ultrasonic tank. [0020] FIG. 7 shows a three-electrode electroplating cell with a gas dispersion tube. [0021] FIG. 8 shows an electroplating system with constant voltage control or constant current control. Continue reading about Platinum surface coating and method for manufacturing the same... Full patent description for Platinum surface coating and method for manufacturing the same Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Platinum surface coating and method for manufacturing the same patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Platinum surface coating and method for manufacturing the same or other areas of interest. ### Previous Patent Application: Bonded metal components having uniform thermal conductivity characteristics and method of making same Next Patent Application: Multiple walled rolled tube and method for manufacturing same Industry Class: Stock material or miscellaneous articles ### FreshPatents.com Support Thank you for viewing the Platinum surface coating and method for manufacturing the same patent info. IP-related news and info Results in 0.148 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
