Lipophobicity
A lipophobic coating has been used on the touchscreens of Apple's iPhones since the 3GS,[1] their iPads,[2] Nokia's N9 and Lumia devices,[citation needed] the HTC HD2[citation needed], the Blackberry DTEK50,[3] Hero, and Flyer[4] and many other phones to repel fingerprint oil, which aids in preventing and cleaning fingerprint marks.Most "oleophobic" coatings used on mobile devices are fluoropolymer-based solids (similar to Teflon, which was used on the HTC Hero[5]) and are both lipophobic and hydrophobic.The oleophobic coating beads up the oils left behind a user's fingers, making it easy to clean without smearing and smudging.[6] In addition to being lipophobic or oleophobic, perfluoropolyether coatings impart exceptional lubricity to touch screens and give them a "slick feel" that eases their use.[7] DIY products exist to restore or add an oleophobic coating to devices lacking one.