"I have a lead wire containing a polyimide jacket. I need to bond the polyimide jacket to a titanium housing. The bond needs to provide a strain relief, and more importantly a fluid-tight seal. The adhesive needs to be rated for long-term implant use. Can you make an adhesive recommendation for this application?"
There are relatively few long-term implant adhesives on the market. NuSil Technology offers MED-2000, which is a one-component silicone RTV adhesive, and MED1-4213 is a two-component addition-cure silicone adhesive. Applied Silicone also offers long-term implant adhesives, such as P/N 40064. Since both companies offer other alternatives besides these, I would recommend contacting their respective sales/technical departments to discuss further.
"I need inert and non-water absorbent adhesive film, with good sealing properties, to cover a surface (ceramic) already covered with a suspension of bacteria (dried). This set will be placed in a stomacher bag that contains culture media and the bacteria should be able to pass from the adhesive film to the media. It must be sterile or be able to be sterilized."
There are a few different options, depending on whether you want it to be sticky or non-sticky, or somewhere in between. Various silicone manufacturers or converters may offer cured silicone sheet in various durometers that would be inert and non-water absorbant. The lower the durometer (A-5 to A30), the better it will seal, but will be soft and “grabby” to the touch. Higher durometer silicone will be slightly easier to handle, but will not be as sticky or grabby as the lower durometer materials. You can go with an even lower durometer with silicone gels for better adhesion, but these need to be on a backing (similar to the tacky gel woundcare dressings or ouchless bandaids). Thin film PTFE or PTFE tape may also be an option. Many of these options will be sterilizable.
"We have a segment of uncured adhesive inside a tube encapsulated with the adhesive DYMAX 204-CTH-F-VLV due to UV-opacity of the said tube’s segment. Does contact with uncured adhesive deteriorate properties of cured adhesive?"
Unfortunately, yes. Uncured adhesive will attack the bond line and the cured adhesive. The extent of deterioration is dependent on the area and volumes in contact with each other, and the duration of how long they are in contact. We would recommend sealing the tube, or removing the uncured adhesive if possible.
Adhesives, Catheter Bonding, Medical