Why choose Gold plated Pt-Ir wire?

Conductivity

90/10 Pt-Ir wire is used in ear implants. I've never heard of them being gold plated. Perhaps something new to promote bio-compliance. I do know they use gold and gold plated wires for conductivity, and bio-compliance. Pt and Ir are in the gold family, so they should already have these attributes.

"Gold is a precious metal, which means that it will not oxidize in air, so its electrical conductivity stays uniform over long periods of time. It is ideally suited for gold electroplating applications. Gold plating offers good corrosion resistance, good solderability, and when alloyed with cobalt, it has very good wear resistance. Gold is commonly used in electrical switch contacts, connector pins and barrels, and other applications where intermittent electrical contact occurs." (from: http://www.proplate.com/gold.htm)

Gold plating 90Pt10Ir makes it easier to attach the small wires used in microelectronic applications. This is important in many implant applications.