The challenge for Apple's new sapphire glass
With an estimated 11 per cent of iPhone screens cracked, the news that Apple will use sapphire in its latest iPhones, and perhaps the Apple Watch, will come as a relief to many.
But Kevin Bullis over at MIT Technology Review, says the company will have its work cut out for it to manufacture the sapphire glass – particularly if it doesn't want even more disgruntled customers on its hands.
While sapphire can be much stronger than the toughened glass now used for most smartphone screens (it is second only to diamond on a standard scale of hardness), if it isn’t processed correctly, it can actually be more prone to breaking.
It all depends on how it is cut and polished as small scratches can make the sapphire glass fracture more easily as its strength depends on the orientation of the crystal.
Sapphire is used in small amounts to make scratch-resistant screens for luxury watches but its expense has limited its application. Apple already uses it to protect the camera and the home button on the iPhone 5S.
The company is investing about $700 million in an industrial sapphire plant in Arizona.