How can a flash drive store information without power?
In: Technology
A semiconductor memory chip is basically a tiny switchboard with many (several billion/trillions of) switches. Each switch stores one bit of data (1 or 0, on or off). Depending on how the switches are made, they can be stable in the on, off, or either position.
Bistable switches (like a light switch in your house) only need energy to change states (e.g. on to off), but not to remain in the same state. These are the type used in flash memory. Energy is only required to flip the switches, they remember what they were flipped to. We call this behavior non-volatile.
I’m contrast, semiconductor memory used in things like RAM use switches that are only stable in the off position. They need energy to remain on (similar to a doorbell switch). This is called volatile memory.
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