Chris Tangora isn’t the first person who’s wanted to customize his iPhone case, nor will he be the last. But he’s arguably the first customizer to use both optical and electron microscopes — not to mention a high-end metal-coating process — to put a metallic finish on his ‘Phone that’s as tough and long-lasting as it is beautiful.
Early on, Tangora rejected a simple paint job due to the inherent difficulty paint has bonding to metal, not to mention the lack of durability. Gold-plating wasn’t the answer, either; while gold-on-aluminium bonding is possible, it also wears off too easily. Before long, Tangora realized that, in order to find a better iPhone finish, he needed a better understanding of the iPhone that the finish would be bonding to…
The first step involved checking an iPhone under a traditional Carl Zeiss optical microscope, the better to understand the unit’s wear characteristics. Here, for example, is a closeup of the iPhone screen that shows it’s unusual "stacked pixel" design that serves as an anti-aliasing tool for text display:
And here’s a 100X closeup of the front bezel, showing the scratches and scuffs caused by lint and dust that dull the iPhone’s luster:
Extreme close-up? For Tangora’s purposes, not even close enough — he needed to know exactly what his iPhone was made of, literally at the atomic level. Luckily for Tangora, he had access to PSU’s $250,000 scanning electron microscope with X-ray diffraction spectroscopy. Here’s what he found:
(Those pictures show, in order: the iPhone screen, made from silicon [glass]; the stainless steel bezel; and the anodized aluminum rear housing.)
Now for the million-dollar question: what kind of metallic finish would bond to both steel and aluminum, stay bonded, and be resistant to the keys and coins in your pocket banging against it? In his research, Tangora discovered a titanium-nitrate (or TiN) process that’s used on hard cutting tools, jet engine blades
and surgical implants. TiN is formulated to be both strong and flexible, less a stand-alone armor than an extra layer of protection for the underlying substance.
Using this plasma enhanced chemical vapor deposition (PECVD or
PVD) tool, nitrogen gas in a vacuum is streamed across a large disk of pure titanium, then electrically charged to create a plasma that deposits titanium atoms on the target surface — in this case, the iPhone’s front bezel. An additional Type II "hard anodizing" process was employed for the rear housing. And, voila:
Tough and beautiful!
Because of the attention generated by the finished product, Tangora originally did a limited edition run (under 100 units) of these "iPhone Customs." The good news is, he and his team are gearing up the TiN process for a new batch of 3G handsets.