'iPhone 6' survives FRENZIED STABBING. Truly, it is the JESUS Phone

Only in the land of dixie

Over the years I've seen the odd video review where they drop a phone from 5/6ft to simulate dropping your phone on the pavement (sidewalk). Drop it into a bucket of water - to simulate (it's lunch time so I won’t pollute your mind with that mental image - Thank you Steven R - bar-steward), all reasonably average simulations of what might happen to a phone real life.

But an "assault rifle"?

Assault Rifle

"We bet many long-time Reg readers would love know what happens when sapphire glass comes face to face with a American assault rifle."

I was thinking more of a fanboi-meets-assault-rifle scenario, but your idea is good too

Surely...

...to be truly the Jesus Phone, it would have to die from the stabbing, then come back three days later? Christ was, in fact, not impervious to penetration by nails, thorns, and spears, although I do not recall if a knife was ever tested.

Safety... fourth. Maybe.

"Here I am, holding the glass. I will stab towards my hand, hoping that the glass does not deflect the blade directly into my fleshy bits."

"And now here I am torquing the glass in such a manner that a failure would splatter my soft, nerve-ending-filled fingertips and palms with shrapnel."

It truly must be a Jesus phone, because it's a miracle this man didn't injure himself.

On sapphire...

As someone who deals with this sort of thing professionally, I'd like to address some of the issues raised here:

* Re: DougS - Indeed, sapphire glass (a.k.a. corundum, alumina, etc.) is exceptionally hard. Scratching it would require something of the order of silicon carbide, boron carbide or diamond. As such, we agree that its ability to handle this abuse is not at all surprising. If you want to challenge the stuff, silicon carbide sandpaper is easy enough to come by, not to mention diamond rings. That said, please note that this may provoke an additional reaction from those to which said rings are attached, especially if they also happen to own the object of your amateur sclerometry.

* Re: DougS, various ACs - Concerning the flexibility, similar things have been accomplished with Gorilla Glass - and we all know how flexible glass optical fibers and fiberglass are. While this sort of thing is always a bit of a shock to see at least initially, given how much stronger sapphire is than glass, this is also not surprising. In fact, you can buy Schott glass screen protectors for digital cameras (Giotto's Aegis product line, for instance) that are of similar thickness and flexible. Bottom line, I can assure everyone here that this is not faked, plastic, etc. For anyone who needs more proof, this video is a lot of fun to watch (though to be fair, just looking at the bend they get in a sheet of glass that size makes me very, very nervous):

http://www.corninggorillaglass.com/gorilla-channel/How-Corning-Tests-Gorilla%C2%AE-Glass

More fun videos like that here:

http://www.corninggorillaglass.com/gorilla-channel

* Re: Admiral Grace Hopper, DougS - Yes, it will blend; a sharp enough impact and this, like all brittle materials, will shatter. A blender should work just fine, though it will dull the hell out of the blades in the process, and make an ungodly racket (iRacket?) as well.

* Re: Mr. Hamill / all other interested parties - If the wish is to know whether sapphire glass will stop an American assault rifle, on this point I can only speculate, but I suppose it would depend on how hard you threw it. As to the bullets coming out of said rifle, since this sort of materials is already in play in the transparent armor market, and has been shown to stop 7.62mm AP rounds - see here:

http://www.crystals.saint-gobain.com/uploadedFiles/SG-Crystals/Documents/SAFirE.pdf

...I would say that the answer is a qualified yes - though I would further speculate that an iPhone 6 is *probably* not an optimal ballistic protection system and that clearly you would need a bit more than a single unit to do it. Now, a *suit* of iPhones, overlapped in the form of scale-mail, with some phonebooks behind to catch the resultant iSpall, that could work, assuming you had the strength to wade through the human swarm that would surely form around you ("How shall we f*** off, oh Lord?", etc., etc.). On the positive side, they too would offer significant ballistic protection, so perhaps this isn't so bad.

* Re: The Man Himself - It is absolutely correct that toughened glass and sapphire have been around for years. Of course, they have gotten better at making these materials over time, but one of the early applications of sapphire glass (which is not really a glass but a single crystal of high purity aluminum oxide) was in bar code scanners at the grocer's - because it's both incredibly resistant to scratching and abrasion (which would otherwise disable the scanner over time). It's also IR-transparent, though as far as I know those scanners generally rely on red lasers, not IR sources.

* Re: DaLo, DougS: The idea that this synthetic sapphire is not "true" sapphire is only accurate in the sense that these do not come from pieces of great big blue stones dug out of the ground. We could just as easily call it ruby glass, since sapphire and ruby are both alumina crystals with minor impurities to give color (you can get other colors besides with the right doping). The difference in the case of the synthetic stuff is that it is entirely free of such impurities - hence no color. As far as I know, adding something would only compromise the properties, so we're talking pure alumina, as pure as you can get.

* One caveat concerning sapphire is that, while its initial fracture toughness is ~4x that of Gorilla Glass, it is not possible to prepare single crystal sapphire sheets with the sorts of built-in compressive stresses that glass manufacturers can build into their materials thanks to their truly glassy (amorphous) nature. As such, the argument goes, the initially high toughness of the sapphire will be reduced in practice because of the generation of microcracks in its surface over time. Once formed, if the material is bent and if there are no built-in compressive stresses to counteract the tensile stresses imposed on the outside of the bend, these microcracks will propagate rapidly, resulting in failure. Corning purports to show this here:

http://www.corninggorillaglass.com/news-events/Corning-Gorilla-Glass-vs.-Sapphire

They're rather down on sapphire more generally here:

http://www.corning.com/news_center/features/gorillaglasssuccess.aspx

Of course, since they sell Gorilla Glass, it behooves them to make the argument. I suspect that those who use sapphire are attempting to address the issues of scratch and abrasion resistance that many complain about with glass screens, and relying on this high level of durability to suppress microcrack formation for a reasonable amount of time. It'll be interesting to see how this plays out in the real world.

PS - To be clear, I do not work for any of the companies referred to here (nor have I in the past), and to date I have not been involved in any research efforts specifically related to the sapphire, glass or Gorilla Glass materials discussed.

Arc_Light

How I learned to stop worrying and love ceramics...

Hi all,

Thanks for the positive feedback and interesting responses! Very nice to see a healthy interest in materials science.

* cray74 - Sounds like we may be up to the same sorts of things from time to time! Totally agree, it's the non-oxide ceramics that win when it comes to ballistic protection, assuming transparency is not a requirement. It's amazing how tough and light the new ballistic protection is, even if the soldiers will always want it lighter (can't say I blame them given how much they lug around). That said, two small corrections:

- Commercial sapphire glass is actually monocrystalline - since the usual crystal structure of alumina is not sufficiently isotropic, it almost has to be to meet the optical requirements (well, barring trickery such as grain orientation in magnetic fields, doping to stabilize more isotropic crystal structures, etc.). Anyway, back to the screens, what we're looking at are single crystals, grown from seeds, then cut down and polished using some very expensive polishing media. This is why you see it used in smartphones but not, say, single-pane windows on the White House or what have you - they can only go so big. For vehicles they have to use multiple panels of the stuff with some binder in between. Frankly, it's amazing that it works at all to grow sapphire glass as they do - some serious engineering, that!

- Concerning the idea that non-oxide ceramics are by definition opaque, this is true sometimes, but not always. In other instances it's more that we suck at making single crystals of sufficient purity. Case in point, silicon carbide. We know it as a darkly colored or black material primarily because the stuff we see contains excess carbon. This is not a problem for sandpaper, but if you want to use it as a wide band-gap semiconductor in power electronics and the like, extra carbon is right out. Among the many different polytypes of SiC out there, you can easily get band gaps large enough to preclude significant absorption of visible light - meaning transparency becomes a possibility so long as you take microstructure into account (for some polytypes you'd need single crystals to get it, for others you might be able to get away with polycrystalline materials). That said, no need to take my word for it - see here:

http://resilienttechnology.wordpress.com/2010/10/15/why-silicon-carbide/

This is from 2010, so definitely not current, but even then you can see the progress they were making as far as both size and purity were concerned. Here's a nice picture of what you can buy these days:

http://www.semiconductorwafers.net/Transparent-SiC.html

The problem is simple - if you think melt-growth of alumina single crystals (Tm ~ 2072°C) is hard, just try it out with SiC (Tm ~ 2730°C) some time :) That said, who knows - in some decades, maybe we'll be talking about silicon carbide "glass" for the iPhone 42... The same folks who make the sapphire glass for Apple also make furnaces for growing high purity SiC, after all:

http://www.gtat.com/Products-and-services-PowerElectronics-SiClone.htm

* Arnaut the less - Well, first, see above - if Venus is where you're headed, I recommend waiting for the iPhone 42. With its beautiful silicon carbide glass shell, the iPhone 42 is the choice of extremophiles across the galaxy! Tired of other manufactureres' cheap diamond screens bursting into flames at the first hint of liquid oxygen? With its superior fire resistance, the silicon carbide casing of the iPhone 42 will stop fire in its tracks. Visiting Venus? Don't be caught with your pants down when the HF starts to fall - just grab your iPhone 42 and call for help! With luck, someone will find your corpse before it fully dissolves. The iPhone 42! It's the answer.

But seriously, SiC really will take that sort of abuse. The resistance of that stuff is insane; it's damn near impossible to etch (another reason it's taken so long to develop as a semiconductor).

Beyond that, you've reminded me of one of my favorite demos concerning microcracking and glass toughness. Take two well-used rods (settle down) of the same diameter based on pretty much any silicate glass you like. Cantilever one off the edge of a table. Have your densest coworker sit on the other end so it won't move (might want to offer them eye protection, a snack, and / or an iPhone 6 to make sure they won't either), and hang a bucket on the free end. Start filling with metal shot; eventually, of course, it will break. Now, take the other rod and give it a quick dip in HF - this eats the glass, the rod gets thinner, and of course, when you repeat the same experiment, the load at break is much higher.

The moral of this story, then, is very simple: For those concerned about the durability and appearance of their new iPhones, simply take them for a quick dunk in some HF from time to time to keep them looking their best. Of course, protecting your health is paramount when doing this, which is why you must always remember to turn the phone off before attempting such a thing. Believe me, you don't want to listen to Siri's reaction to The Process. There are certain things you can't un-hear.

* Lis 0r - Absolutely correct - blenders are funny that way, far more often it's about bashing, broadsword-style, than slicing, in spite of how we call the pointy bits "blades" and shape them accordingly - at least, superficially anyway... I expect that whatever is in the blender will experience higher localized stresses when bashed by a dull blade than by a really dull blade due to the increase in contact area as the dulling process continues, but the mode of action is definitely not obvious at first glance. I forget whether it was on Mythbusters or somewhere else, but I recall seeing some slow-mo video of a blender in action that proved the point - very cool.

* JLV - It'll take more than a grain of salt to do it, but have no fear, you'll still be able to break the iPhone 6 screen, if that's your thing - and yes, the replacements will not be cheap. This is why I must reiterate the importance of dipping your iPhone 6 in HF on a regular basis; it's the only way to be sure.

PS - As another example of insane and unexpected flexibility in materials we would normally refer to as rigid and brittle, check this out:

http://www.businesswire.com/news/home/20120319005667/en/Silicon-Genesis-Announces-Generation-Polymax%E2%84%A2-Production-Equipment

That's a 20 µm thick polycrystalline silicon wafer. For the record, silicon has a stiffness ~2x that of glass and maybe a half to two-thirds of that of sapphire.

PPS - There are two kinds of people in the world with access to HF - those who know to treat it with respect and those who soon will. Would strongly suggest not going for a Darwin Award based on anything I've said here.

Arc_Light