Iridium as a coating for magnets
I got this idea from fountain pens, the tip on the nicest ones is iridium.
Basically I wonder/suggest coating an implantable magnet with iridium.
other metals include iridium-platinum alloy, simply platinum and iridium-oxide.
All of these are very expensive metals, but a coating is quite thin and even if a magnet is an astronomical 500USD over 5 years for it would be under 30¢ a day and possibly guarantee safety.
Iridium platinum and plain platinum is already widely used in medical implants
These people say Iridium is the most corrosion resistant metal
These people think its a such good idea to use iridium-oxide that they want to stop others from doing it
One issue other than cost would be sticking it on the magnet.