How do USB Flash Drives store information?
In: Technology
They have tiny bits of silicon surrounded by insulators called cells. When a flash drive writes information, it turns on the cell it wants to write to (by using electronic switches called transistors) and zaps the cell with electricity. Normally electricity can’t go through insulators, but with high enough voltage you can force it to quantum tunnel (a bit beyond ELI5 range). Think of it as lightning, normally air is an insulator but lightning is high enough voltage to go through it anyways.
To read the cell, it turns on that cell using the transistor switches and runs a current near the trapped silicon cell. If the cell contains electricity from having been previously zapped, it will affect the current, which your computer can measure and determine whether the data stored in that cell is a 1 or a 0.
To make it more complicated, we’ve gotten more precise with how we zap the cells so that we can store more than just a 1 or a 0 in it. We can store any value from 0-7 in a single cell, and the reading process will be able to tell exactly how much electricity is store inside the cell to figure out which value from 0-7 is stored in it.
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