This topic has two meanings, namely
1. Design something that is naturally microscopic in size. Bacteria, virus, bugbear, skin mites, etc. If it's nigh impossible to see with the naked eye then it counts.
Like my Bacteriophage

Or Petr Stuchly's Flat Mite

2. Design a model and then make it as small as humanly possible. You must post a side by side of a properly sized model and micro model so that the design can be properly judged. Smaller the better.
Example is my shark

Or this Rooster folded by Anja Markiewicz

Materials:
Any size and shape of paper
Multiple sheets allowed
Not cuts
MC allowed
I feel like if you make a micro Mike Rowe you should automatically win, but I'm not the judge this month, Marsch is.
Good luck everybody!
Edit: I'm sorry if this wasn't initially clear, but you can do either one or two. That is, if you design a microorganism, it doesn't need to be folded small, and conversely if you choose to design literally anything else it must be made micro. A sort of trade off for either choice.