What do you mean by resolution? Layer thickness? Positioning accuracy across the whole build surface? Repeatability? 100 microns suggests way more accuracy and fine finish than any FDM is doing. The idea that a rapidly moving head running on skinny round rails is achieving position accuracy of 0.0039" is someones imagination. Add material shrinkage and such and it is damn near impossible.

I have built a CNC mill using high precision THK linear rails driven by 20mm THK ballscrews. The work envelope is 18" x 18" x 18". It is mounted to a cast iron table top weighing 205 lbs that was hand scraped dead flat. When I set my 9" x 9" granite surface plate down it floats for a moment on a cushion of air! The steppers are 800 oz/in driven by a 68 volt power supply. So even though the total moving mass is about 100 lbs it still moves pretty quick. I am in the process of adding a 12" x 12" heated build plate and an extruder head. I can move in any direction and repeat back to a stopped position repeatably to 0.0002". It will be interesting to see what the 3D printing will look like, but I'll bet I won't get to the 100 micron resolution people like to quote.