In a (great) article written especially for the Gizmodo, Bill Nye (aka The Science Guy) explained the scientific principles behind the new iPhone 3GS oleophobic screen in an adorably didactic way. Of course, the full text is in English, so I’ll cover the main points here (and add a few touches from my experience as a teacher). To those who can venture to read the full article, I highly recommend it: a pleasant and enriching reading!
Fear of Leo
For those who enjoy etymology, the meaning of “oleophobic” is very obvious: “who is afraid / hated by oil”. (In Chemistry classes, you have certainly heard the equivalent hydrophilic, which ends up resulting in the same thing.) With such property, instead of a fatty substance (or apolar) spread across the screen of the new iPhone, the molecules try to cluster. The principle is the same that makes oil not mix water, guess what: it is also oleophobic!
The great thing was to take a substance with such property and cover the iPhone screen with it. For that, it was necessary to make some compound to firmly attach the oleophobic coating to the glass (have you thought, if the protection peels off?).
Connecting the dots
The solution that Nye imagines to have been employed (the assumption is due to the fact that the method actually used is secret and expensive intellectual property of Apple and / or others) is an ambivalent third molecule. Detergent type, which binds water and fats at the same time (a molecule amphtera). In this case, it could be silane: a compound capable of binding to the inorganic silicon of the glass on one side and to the organic carbon polymer on the other. Many applications for it already involve "sticking things", so the application makes perfect sense.
In the end, what do we have? A marvel of applied science that makes the grease of your skin, instead of adhering to the glass, repelling resulting in an unprecedented ease of cleaning: washcloth, so clean! For those with oily skin, now it's not so much to answer a call on an iPhone, right? I only hope that in the future, _everything_ will have this coating.