One of the most prevalent concerns when bonding materials is how to get a strong bond between mismatched substrate surfaces. Generally, when bonding like materials, there are adhesives available that will strongly bond the two surfaces at the interface of the substrates. However, in many manufacturing scenarios the need to bond different materials with very dissimilar physical and chemical properties frequently arises. For example, a reasonably rigid material such as polycarbonate (PC) may need to be bonded to a more elastic polyethylene (PE) material. Since the chemical makeup of these materials is quite different, they will tend to bond differently to various adhesives. A certain adhesive may bond well to the PC, but not well – if at all – to the PE, and vice versa.
There are methods to chemically treat the surface of one or both of the materials using primers, or other mechanical means, such as sanding, to get a strong adhesive bond. While many of these chemical methods work quite well, they require the use of materials that may expose the manufacturer to dangerous or toxic matter. Such materials may also require expensive or time-consuming disposal methods. Most importantly, many toxic or dangerous materials cannot be used in the manufacture of medical devices that are implanted in the human body.