The Phone in Your Hand
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Take it apart on the device it describes.
Scan, or open<br>everythingmachine.io/phone
Your phone is the most intricate machine you’ve ever held.
Screen<br>Senses<br>Head<br>Body
Let’s take it apart.
Run your finger across a window. Smooth, but it drags. Now do the same on your phone. Your finger glides.<br>The difference is a non-stick coating one molecule thick, and every time you touch the screen a little of it wears away.<br>Oleophobic Fluoropolymer<br>IntroducediPhone 3GS2009<br>Like a non-stick pan, the screen is coated with fluoropolymers, chains of carbon atoms with fluorine attached instead of the usual hydrogen.<br>The carbon-fluorine bond is incredibly stable, giving the coating very low surface energy: oily fingerprints wipe away, and your thumb gets that gliding feel. It also explains why a phone left face-down on the faintest slope will attempt escape.
The first iPhone Steve Jobs revealed on stage had a plastic screen. In the months before shipping, he found the keys in his pocket had scratched the prototype and he insisted on a last-minute upgrade.<br>The chemically strengthened glass he demanded is seven times stronger than normal glass and quickly became the industry standard.<br>Aluminosilicate Glass<br>IntroducediPhone2007<br>Normal glass, like bottles and windows, is made from silica. Smartphone glass has aluminium woven into the silica network, stiffening the structure and helping it resist cracks.<br>Sodium ions are also added to the mix and sit in the gaps of the silica-alumina grid. The finished sheet is dipped into a 400°C potassium bath. The small sodium ions swap places with large potassium ones, squeezing into the structure, compressing the surface.<br>When an impact occurs, a crack must first push through this compressed layer.
Your finger is tracked by capacitive touch, shown live at the bottom.<br>Older touchscreens were resistive, like on the Nintendo DS. They required a push, often with a stylus, to force two layers together. They could only detect one touch at a time and included a screen-dulling air gap.<br>Capacitive touch made the glass itself a multi-touch sensor, and buttons disappeared to free up more screen.<br>Capacitive touch detector<br>IntroducedLG Prada2007LG narrowly beat Apple to market, but Apple paired the hardware with the gestures we all still use: flicking to scroll, pinching to zoom, and making pages glide and settle as if they have weight.<br>Conductors have a bunch of free electrons that carry electricity, but they also reflect light. That’s a problem for something in front of a display, but indium tin oxide has a rare trick. It has just enough electrons to conduct without becoming a reflective electron-sea, making it both transparent and conductive.<br>It’s arranged as a whisper-thin grid and holds a tiny electric field. When your finger touches the glass above, it disturbs the field where it lands. A controller chip scans the grid hundreds of times a second, looking for those tiny changes and turning them into coordinates.
The display you’re reading this on is an absurd grid of exactly 0 tiny, multicoloured light bulbs, known as pixels.<br>Turning them on in a pattern creates the shapes and colours on the screen, with a few hundred forming each of these letters. When you scroll, the text is not really moving. Pixels are lighting and dimming more than a hundred times a second.<br>AMOLED & TFT<br>AMOLEDBenQ-Siemens S882006A classic bar-style phone with an AMOLED display smaller than a passport photo. Eight of them would fit inside the screen you’re reading on now.<br>Every pixel is made of subpixels: microscopic red, green and blue lights, which blend in different amounts to make any colour on your screen. A light bulb needs to be connected to power, so a layer of transparent indium tin oxide carries power across the top, and a metal layer feeds power from below.<br>Left like this, the screen would just glow at full brightness. An expensive, big flat light. So, the subpixels sit on a layer of thin-film transistors: millions of dimmer switches, controlling the brightness of each pixel. Beneath it all, a final slab of glass protects the delicate filling.
Three tiny eyes look out from the front of your phone. You can see the selfie camera. If you’re older you might remember the workaround: a phone with a tiny mirror-dimple on the back, so you could line up your own face.<br>The other two eyes are hidden. They measure light to automatically adjust the screen brightness, and to stop your cheek from hanging up a call. Try holding your awake phone to your cheek and slide it around, nothing happens.<br>Front Camera & Photodiodes<br>Front CameraKyocera VP-2101999The first camera phone was front-facing. It could do a kind of stop-motion video call at two images a second, or save up to 20 grainy photos.Proximity SensorNokia 76502002No touchscreen, so the proximity sensor was for switching a call off loudspeaker.<br>The proximity detector and light sensor both use light-sensitive...