Will hard drives ever reach a physical capacity limit?

[michaelpendred]

I have seen over the years how the 3.5" disk drive has increased in capacity where we now see 12Tb drives and I was wondering if one day we will reach a limit where it is no longer possible to increase the capacity any further due to physics (or something like that) and at that point, if hard drives were to be made with a larger capacity, the overall size of the drive will have to be increased from 3.5" to something else.

 

[Nigel Spike]

Some info here.