Phil Hobbs wrote:
William Sommerwerck wrote:
"Phil wrote in message
m...
William Sommerwerck wrote:

Wouldn't it be possible to make the polyimide conductive by rubbing
graphite into its surface ("The Audio Amateur" had at least one article
about home-made electrostatic speakers that showed how to do this
with Mylar), then plate it?

I'd be worried about the film adhesion--the nickel would only stick as
well as the graphite. Plating plastic involves stuff like chromic acid
dips, reducing palladium salts to form Pd nucleation sites on the film,
and then electroless plating.
Not your ideal home project unfortunately!

Thanks for the clarification.

This is the sort of problem you'd think would have been solved decades
ago.
The original SX-70 used copper-coated (plated?) polysulfone, which was
then
plated with nickel and chrome. The plating sticks to the plastic with a
tenacity that's almost unbelievable. You actually have to break the
plastic
before the plating comes loose.



Oh, it's been solved, all right--Minco advertises nickel film RTDs. I
tried to get them to make the films, but they either couldn't or didn't
want to, and I didn't want to have to deal with making artwork--I'm
going to pattern it with a Sharpie and some ferric chloride. (Ferric
chloride works well on thin sputtered nickel, so I'm hoping the plated
stuff doesn't have some weird passivation. I should try it out on a
bolt or something before I take the plunge. Of course I can also
electropolish it away in KOH solution.)

BTW the Minco rep is a good guy, who gave me a steer to somebody who may
be their supplier--I just haven't heard from them yet.

Anyway, if it works, I'll try licensing it to them. It should be
good for at least 100x reduction in thermal forcing for the down-hole
application I'm working on--sort of the thermal equivalent of a Faraday
shield.

Cheers

Phil Hobbs

Jut had a dumb idea..how about unrolling mylar or other plastic caps?