I recently got a nexus 4. Nice looking phone. Front and back have corning gorilla glass. I like how it feels without a bumper or case but a drop from chest level onto pavement would likely shatter it. I compromised and used just the bumper and hope for the best.
Is there anything in development that will allow a reliably shatterproof glass? Say a 5 foot drop onto pavement ? Maybe they have it but can’t mass produce it economically yet? Or is corning in the same bind as battery makers where they’re hitting physics or chemistry barriers and improvements will be small and slow if at all?
No. Why? Because every tenth of a millimeter you spend on glass is a tenth you don’t spend on battery, or electronics, or just making a thin phone. Phone screens are astonishingly impact resistant for what they are.
Gorilla Glass is getting slightly better over time, but to really make an impact resistant screen, you need something thicker.
An alternative is to use a material with more yield, like plastic, but those materials are almost by definition softer, and therefore less scratch resistant. So there’s another tradeoff.
Someday we’ll have solid diamond screens. But they’ll still shatter if they fall onto concrete the wrong way, because they’ll be just thick enough to survive your pocket, not a hard drop on to concrete. Most people don’t need their phones to be any stronger than that.
The next thing is likely to be synthetic sapphire - which is possible now but horrendously expensive. TAG and, I think Vertu, use it for their multi thousand dollar phones. Leica put it on the screens of some of their cameras too. But as Dr. Strangelove notes, this doesn’t get you shatterproof, just essentially scratch proof. Sapphire has been used for decades on better quality watches, but interestingly was not preferred for watches that are subject to physical abuse that may shatter the glass. Here acrylic or mineral glass were used. However, given that 99.9% of all such watches are now fashion accessories and not actually ever used in such rigorous circumstances sapphire has become ubiquitous.
The problem with sapphire is that you have to grow a crystal, and that isn’t easy. Growing a nice long cylindrical crystal 40mm wide isn’t hard, and you can slice many watch glasses off one. But a phone screen cover requires a bigger crystal and you have to slice it lengthways (eg quarter sawn) so you get only a few sheets per crystal (and lots of smaller bits.)
ETA - the other, and more likely, proposition is Corning’s Willow glass. It is so thin that its flexibility makes it close to shatterproof. Corning are pushing it for new applications, but as a cover glass it may well simply become a close to indestructible cover for ordinary phones.
Do you want material that resists scratches, or resists impact?
The harder the material, the more resistant it is to scratches, and more vulnerable to impact damage. Synthetic sapphire is being eyed for phones, which will be lovely for resisting minor scrapes and dings, but you won’t like what happens when you drop one.
How fragile are iPhones, anyway? I’ve dropped my Samsung so many times I can’t even tell and all it did was fall apart. No screen shatter at all. Snap it back together and you’re good to go!
Aren’t sapphire windows used for supermarket barcode scanners? IIRC, they’re made to stand up to years of getting banged up by canned goods and other heavy objects.
And, how thick is the window?
You could easily make a phone proof from any normal injury if you made it with 3" thick armored glass, but that might make it difficult to put in your pocket.
There’s no substance that is scratch and impact proof in the thickness that cell phones demand.