How Do Touch Screens...Touch?

how can a piece of glass know you're touching it what kind of black magic is this like at one point your phone screen was literally just sand and using science and technology that sand became this Yes actually let me show you how step one get some glass first melt some high Purity silica sand and pour it into a mold sort of thing boom glass but that glass breaks really easy not good so we give that glass a chemical manicure and make it very strong we call this gorilla glass step two the touch there are two

kinds of touch screens the one your phone uses and the Annoying kiosk at McDonald's first let's talk about the McDonald's kiosk this one has two layers usually being plastic on top and glass behind it both pieces are slathered in a conductive material that means when they touch it makes electricity so if you put one just a little bit in front of the other and attach them to something you get a touchcreen but wait it knows it's being touched but how does it know where it's being touched well you remember that slathering from earlier it's actually

a very precise slathering where we lather in a grid pattern so if you touch right here it will send electricity to the processor like this and the processor can match up with what's on the screen and register if it does anything pretty cool except it sucks and you have to put an annoying an an annoying and you have to put an annoying amount of pressure for it to work and it's not reliable but it's more durable and lasts longer which is why big companies like McDonald's use it so they don't have to maintain it as

much the other kind is what your phone laptop and pretty much any personal device almost always us uses this one has four layers the top layer is the tough glass we talked about in step one which besides being kind of strong there's really nothing special about this glass it's just glass but below that glass we have two clear diamond shaped grids with a clear insulator in between them but I'm going to make them colored cuz it's easier to explain the grids are made with a material called I which holds electricity really well and it's actually

the same stuff we slathered on the McDonald's kiosk but this time it's just on its own under some glass if we zoom in on the bottom grid we'll see a ton of little electrons just chilling they do this because there's an insulator in between the two grids so the electrons are kind of stuck they really have no choice but to chill and because these electrons aren't moving they generate a negative electric field which causes the top layer to store a ton of positive charges this my young Padawan Learners is what we call a capacitor it

build an electric field and it's used in a ton of stuff so if you were to put something that can inducts electricity close to this capacitor like a hot dog it messes up the electric field this changes the amount of positive charge on that top layer now keep in mind your phone knows exactly how much charge is supposed to be on each top Diamond so the processor in your phone does the math and says yo there's a change in charge on diamond x50 y 173 then the chip in your phone will look at what's displayed

on x50 y 173 and if clicking there is supposed to do something meaning if you tap right here nothing happens but if you tap right here your phone matches it up with what's on the screen and subscribes to this okay but why do touch screens work with fingers and hot dogs but not gloves also why does your touchcreen act all weird when your hands are wet it's because like I said before your finger and a hot dog conduct electricity that means when you put your finger near your phone screen the electricity from the capacitor literally

runs through your finger and that's what makes the change in charge a glove however is an insulator meaning electricity ignores it so there's no change in charge then you might say but what about water water conducts electricity and that's true the problem is when your hands are wet the water activates at multiple points at the same time and your phone just kind of gets confused all right so we have some glass the clear magic electricity stuff but what about the screen itself the colors how does that work step three display everyone thinks they know how

pixels work and they probably do basically if you zoom in on your screen really really really really close you'll see something called a pixel each pixel is made up of three baby pixels that are either red green or blue on top of each baby pixel is a dimmer so if you want this pixel to be the color red you'd completely dim green and blue if you want the color purple you'd dim green completely and do 50% red 50% blue if you want white you do them all at 100% basically these three colors can make any

color and because you have millions of pixels you can make any image jit crazy after all eh anyway that's going to cost you one subscribe and the McDonald's kiosk is going to ask you a few questions