Samsung's 8th generation Flash NAND (which is used to create Samsung SSDs) is 236x layers thick. Effectively forming a 3d mesh (albeit the mesh is created one-layer-at-a-time, but any 3d structure probably would be done like this).
That's how modern SSDs achieve so much density. Alas, the machinery to etch silicon chips in this way remains very expensive, so I bet that Tape and Hard Drives remain the price-per-TB king for the foreseeable future. I'm pretty sure SSDs have won the density crown however.
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IIRC, BluRays achieved 4x layers through focusing the laser, reaching 100GB per disk back when BluRay research was still popular (15 years ago or whatever). I don't think it ever was a popular format, but it existed as a crude 3d layer.
I guess Hard Drives are like 8x platters or more, achieving a degree of 3D as well.
But I presume you're talking more about technologies that achieved hundreds of layers (Tape, thanks to "rolling up", or SSDs/modern Flash with 200+ layers, etc. etc.)
That's how modern SSDs achieve so much density. Alas, the machinery to etch silicon chips in this way remains very expensive, so I bet that Tape and Hard Drives remain the price-per-TB king for the foreseeable future. I'm pretty sure SSDs have won the density crown however.
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IIRC, BluRays achieved 4x layers through focusing the laser, reaching 100GB per disk back when BluRay research was still popular (15 years ago or whatever). I don't think it ever was a popular format, but it existed as a crude 3d layer.
I guess Hard Drives are like 8x platters or more, achieving a degree of 3D as well.
But I presume you're talking more about technologies that achieved hundreds of layers (Tape, thanks to "rolling up", or SSDs/modern Flash with 200+ layers, etc. etc.)