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Peter Cochrane's Uncommon Sense: G force
Ruggedisation - in a (horribly made up) word
Ever slam down a handset, sit on a mobile phone or dent a laptop? These days the odds are they'll continue to function. Peter Cochrane asks where advances are taking us...
The escalator down to the baggage claim area at Miami airport is very steep and long. Today I get to the top of it after two weeks of continual travel and in a slightly dazed state. I somehow manage to unclip my mobile phone from my belt and it flies down the escalator, bouncing three times.
At the bottom there is a pilot and I shout a warning: "Mobile phone on the way down!" He is obviously a football player - instinctively he turns and traps my phone with his foot in one smooth action. Terrific, no one got hurt.
I'm pretty sure this is the end of my mobile communication for the trip. With some gratitude I accept my phone from this rather talented pilot and I'm somewhat amazed to find it is slightly scratched but still fully functional. This is a little surprising as this same mobile phone has similarly been dropped three for four times in the last six months. (I suspect that the bad design of the belt clip on this particular model is a ploy to sell even more phones.)
What is really astonishing is that this technology is so resilient against such huge acceleration and deceleration. At a modest estimate, the g-force exerted on the phone when it hit the floor, must have been in excess of 30g. Such a force would kill a human instantly and only 10 years ago would have seen a mobile phone inoperable and smashed to pieces. Now it doesn't even see the cover flip off or the battery displaced.
Just 25 years ago I was designing and building test equipment for applications that dictated a military specification. One crucial test was to take equipment and drop it from a height of one metre onto a solid concrete bed, on each corner at a time, and it still had to remain fully functional.
To say the least this was a tough specification to achieve. Even the 1m-drop test inflicted a significantly huge g-force on discrete components and could tear them from their mounting. For the designers of missiles where forces are measured in the 100s or 1,000s of g, rugged operation was an even bigger headache at that time.
What has changed? The large scale integration of components is the key secret.
Instead of 1,000s of transistors, capacitors, resistors and wire leads mounted on printed circuit boards, we now have integrated circuits bonded onto substrates devoid of leads and, more importantly, almost devoid of any significant mass. The opportunity for mechanical damage has therefore been vastly reduced over the last 25 years.
In the equation of: gravitational force = mg, there is nothing you can do about g, unless you leave the planet, so reducing m is the only variable at our disposal. So if you reflect on the size and weight reduction of mobile phones over the past 12 years, it is clear we have gone from around 1kg to a around 0.01kg, a reduction of >100:1.
Mobile phones, wrist watches, pocket calculators, cameras, voice recorders, MP3 players and more are now achieving a robustness and operational capability in excess of military expectation. The other major improvements have been increasingly durable plastics able to withstand mechanical, electrical, chemical and user abuse.
In the next phase we can expect to see the components embedded in plastics and fabrics in a similar manner to the steel wire and hardcore in reinforced concrete. From thereon the trajectory is towards the production of devices that will almost literally last for ever. The single most critical components are now the I/O and battery elements but even these are being integrated as polymer displays, batteries and touch sensitive elements along with acoustic transducers of phenomenal performance.
Our ability to do more with less material year on year and achieve higher and higher performance at the same time shows no sign of diminishing or slowing down. Indeed it appears to be accelerating. We already see elements of self-repair in integrated circuits, processors and storage devices, and it is becoming increasingly commonplace in all our systems.
Historically we have come from a direction of high tech and military performance migrating down to toys. Today the flow is being reversed, as our toys become increasingly leading edge high-tech. We see the military purchasing GPS and other IT equipment from the same sources you and I enjoy. In the Gulf War the military were shipping GPS receivers to the troops in the desert because the mil-spec devices were unavailable at the time. And it turned out that the most reliable IT used was a laser jet printer purchased from a high street store.
This is a trend that is bound to accelerate with the changing nature of war, the integration of conflict into society itself, and the simultaneous availability of all technologies to all factions.
Where do we go from here? I think it will be smart materials - where we combine electronic processing and storage within the very fabric of everything we produce.
Not so long ago a carriage clock was a big, cumbersome, expensive, relatively inaccurate and unreliable item of great value. Today we wear the time and the wristwatch is compact, convenient, inexpensive, incredibly accurate, reliable and of little value. Mobile phones are treading the same historical path, as are PDAs. Ultimately, I suspect, so will the PC and all forms of computing.
I for one would like to wear all my IT - mobile phone, camera, computer and everything else in the same way I wear my glasses, watch, signet ring and clothing. But I don't want to look like the back of a PC! It has to be stylish but most of all it has to be reliable, durable and extremely easy to use.
This column was typed on my Apple laptop on BA 275 flying London to San Diego and emailed to silicon.com from Loews Coranado Bay using a broadband connection in my hotel bedroom.