I want to make around 40-200 g of metal cylinders that would ideally have a length of around 1-100 μm in size (smaller preferred). The rods will be made of some ferromagnetic material such as Iron or Nickel.
The reason for this is to make a magnetic field display where the tiny metal rods are submersed in a viscous liquid which is trapped between two clear sheets of material (likely glass or acrylic).
Since these are rods and not balls, this should allow them to stick end to end without bunching up so much and better visualise the magnetic field lines.
Although i'd prefer The rods to be smooth, they don't necessarily have to be a cylinder shape, they just have to have a length to width ratio higher than 2:1 (although i'd prefer a bigger aspect ratio than that).
It is preferred, but not necessary that the rods are all the same length with minimal variation in size.
Last preference is for the metal to look shiny rather than black as this helps a lot with visualising the field lines. I'll take what I can get though.
Haven't found anything online like this but I also don't really know what to search for.
I thought of using thin iron/steel wire and cutting it up but this process would most likely be too difficult and tedious to carry out unless I could construct some machine or jig to do it for me. I also have struggled to find any sort of ferromagnetic wire smaller than 0.1mm which would still be too thick for what I want.
I also thought of long metal shavings but they tend to be twisted and irregular (and possibly too flat) to work well for this.
Perhaps I could use some sort of micro 'cheese grater' to grate pieces off of a metal block?
Could these rods be synthesized via electrolysis somehow?
I'm at a loss so any help or pointers on how to go about this would be greatly appreciated!