eli5: What exactly is silicone and why is it so essential to making electronics ?
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Silicon =/= silicone.
Silicon (Si) is an elemental semimetal. It’s a semiconductor, meaning it’s worse at conducting electricity than pure metals, but better than insulators. It’s an essential component in solid state transistors, the fundamental building block of digital computers since the 50s. Without silicon, you can’t make electronics.
Silicone is a catch-all term for various types of organic silicon compounds. It is generally a rubbery, elastic material used in all manner of applications, from industrial machinery to children’s toys.
Silicones are a type of plastic. But it can also come in the form of an oily or slippery fluid. They are a manufactured product that can be used as lubricants, oils etc or formed into a rubbery type material that can withstand very high temperatures and resists things sticking to them.
They might perhaps be used in equipment or used as seals.
Do you mean silicon, the semiconductor element that microchips are made out of, or silicone, the rubbery compound used for seals and the like?
Silicone is a great high temperature plastic. Silicon is an element that conducts some electricity, and the properties can be changed a lot by adding bits of other elements, making it do things like only letting electricity pass one way, or act as a gate.
Silicon can be used as both a conductor of electricity or an insulator, depending on what other elements it is combined with.
This allows us to make the transistor, which is an electrical component used in all electronic devices. Transistors can be used to amplify a signal or as a switch for an electric signal.
A bunch of transistors can be combined in clever ways to make the CPUs that make up a computer.
First, we need to distinguish between the element *silicon* and *silicone* which is a polymer made from silicon and oxygen. Silicon is what electronics need.
Silicon is a *semiconductor*. That means it kind of wants to conduct electricity, but it also kind of doesn’t. Silicon is like carbon, in that it has 4 electrons in the outermost shell. Atoms are most stable if there are 8 electrons in the outermost shell. Elements with more than 4 electrons tend to try to grab more electrons and fill up that shell. Elements with less than 4 tend to try to get rid of electrons so the “outermost” shell is empty and the next lowest full shell becomes the outermost shell. Different atoms will share electrons between each other so that they can all have a full (or empty) outer shell. Since silicon has 4, it can give up electrons *or* gain electrons. Multiple silicon atoms together will share with each other [like this](https://www.pveducation.org/sites/default/files/PVCDROM/PN-Junction/Images/BOND-SI.GIF) so that *together* each atom has 8 electrons.
It can also be “doped” with other elements to change how conductive it is. Let’s look at a really simple example like a *diode*. A diode is kind of like a check-valve or gate for electricity that only allows it to flow in one direction through the diode. A diode is made of two sides with silicon that are doped with different elements that make them *positive* or p-type and *negative* or n-type. For the positive side, boron is added into the silicon. Boron has only 3 electrons in the outer shell. Like the silicon around it, the boron atom wants to share the electrons so that together all of them have 8, but since boron only has 3 to share with the silicon’s 4, that means they’re missing one. This creates a positive “hole” that an electron can fall into. That electron has to come from somewhere, which is going to be one of the silicon atoms next to it. Now that silicon atom is missing an electron and will want to grab one from another silicon atom. This allows the “hole” to move around inside the silicon and makes the piece slightly positively charged, or p-type.
If phosphorus is added instead, the silicon becomes slightly negatively charged. As before, the phosphorus shares its electrons with the silicon to form 8, but since phosphorus has 5 instead of 4, there’s an extra electron that needs to go somewhere. That electron gets in the way of additional electrons that may want to flow through the silicon. That makes the doped silicon slightly negatively charged, or n-type.
A diode is made by putting n-type and p-type pieces of silicon together, [like this](https://i.pinimg.com/736x/e5/0b/17/e50b172ea3af5cb18d9494613993a5cb.jpg). Where the two sides are touching, the extra electrons from the n-type flow over and fill up the holes in the p-type, creating the neutral region between them. If a voltage is applied that wants to make electrons flow from the n side to the p side, current will flow. The positive side of the voltage “sucks” electrons out of the p-type silicon, creating holes that electrons can flow into from the n-type side. The negative side of the voltage pushes electrons against the n-type silicon, creating a pressure to keep pushing electrons from the n side into the holes forming in the p side.
If the voltage is reversed, though, current can’t flow. The negative side of the voltage fills up all the holes in the p-type silicon, but the extra electrons in the n-type silicon get in the way and stop more from moving over. The positive side of the voltage will suck away some of the extra electrons from that side, but that doesn’t make positive holes, it just makes the silicon neutral. There’s still no room for additional electrons to come from the now-full p-side. So, no current will flow (until you apply so much voltage that it overloads the diode and breaks down the silicon).
More advanced parts can be made by doping the silicon and arranging [it the right way](https://www.electronics-tutorials.ws/wp-content/uploads/2013/09/tran5.gif). You can use voltage to control whether or not there are holes or electrons in the silicon, which would either allow current to flow or block current from flowing. This lets you use one signal to control another signal.
Silicon the element used in electronics is basically sand.
You take lots of sand melt it and purify it Until you have pure silicon, which is naturally organised in a neat crystalline form.
This alone can not really make electronics, but you can add other elements into the silicon layers, to either create a Electron surplus, or deficit.
By combining those different layers you can create a transistor, which is basically a switch that can decide if electricity is flowing, if the switch is pressed (by electric input)
Now you combine billions of those and you can make CPUs, and all those mind for electronics.
Tldr, it’s cheap, it can easily be manipulated for different electric states
A professor of mine once said, “You want silicon in computer chips and silicone in breast implants. You don’t want to mix them up.”
Silicone is a rubbery polymer, and not used in electronics.
Silicon is the 14th element on the periodic table. It is in a group of elements between the metals and nonmetals called metalloids. It has some properties of metals and some properties of nonmetals.
One of those properties makes silicon what is known as a semiconductor, meaning in sometimes its a conductor, and sometimes it’s not.
This allows us to make a switch with no moving parts called a transistor. We do this by changing the conidtions in a piece of silicon so it no linger conducts. Before this, we had to use vacuum tubes, which have a beam of electrons shooting through it, consume a lot of electricity, and need to warm up before use, and are much bigger.
Transistors now a days can be as small as 2 nanometers, meaning we can fit billions on single chip, rather than vacuum tubes, the smallest of which is 1/4″ around and 1″ long.
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