Rohan,

I realize this question is quite old, but I'll provide an answer just in-case you are still looking for a solution to this problem.

Based on the actual sizes you need, you could consider additive 3d printing as an option. Many of the FDM printers could work if you aren't printing as small as 100micron (say closer to 300micron resolution required), and SLA could be used for finer resolution. Comparison of resolution available on 3d printers: https://all3dp.com/3d-printer-resolution/

You can print in chemically resistant polycarbonate, polypropylene and other filaments but these "exotic" filament types will take some optimization for manufacture at such small scale. You could likely get the performance you need out of a sub-$1,000 printer, and could get manufacturing scale by having multiple machines.

If you want an off-the-shelf solution, Dolomite Microfluidics offers a 3d printer (looks like FDM or modified FDM) known as the "Fluidic Factory" that uses COC (cyclic olefin copolymer) and is designed for microfluidic manufacturing/prototyping, but only down to 300 micron resolution. They do have a solution for manufacture of smaller components using commercially available microfluidic chips and 3d printing on top of them (hybrid manufacture). This would be very dependent on the ability to purchase a finer-resolution component of course. Not sure on the cost of this instrument.

https://www.dolomite-microfluidics.com/product/fast-microfluidic-prototyping/

Hope you found a solution.