Flexible membrane material between silicone oil and sea water

Hi there,

A sensor we're designing requires a flexible membrane to separate sea water from silicone oil (polydimethylsiloxane). Can anybody recommend a sheet material that can be bonded to a stainless steel substrate?

Thanks in advance,


Reply to
Loading thread data ...

Glass is inert against sea water, and a microscope cover slip is thin enough to be flexible. Aquarium cement certainly would have good adhesion to the glass, and probably to the stainless as well. However, if it is a silicone adhesive, it might lose adhesion in contact with the silicone oil.

Stainless steel shim stock is available as thin as 0.001", which is quite flexible. However stainless corrodes in contact with sea water.

Titanium might be a possibility, if thin sheets are available. Checking on:

formatting link
don't see anything thinner than 0.035", which I don't think would be flexible at all.

I have a thin tantalum sheet I bought on eBay, which is somewhat flexible, but you probably won't be able to find another one. This one was made for the proverbial metal plate in the head (to repair cranial injuries). I don't think they repair heads that way anymore.

Polyimide, polyethylene, and polyethylene napthalate are used as flexible printed circuit substrates, which is a fairly demanding application. Epoxy adhesives are often used to bond them to copper foils.

Among plastics, beware of the possible effects of water absorption. Kapton is about 4% water at saturation. If you go with polyimide at all, Upilex-S from Ube has much lower water absorption, only about 1%.

Reply to
Mark Thorson

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.