microfibril

/ˌmaɪkroʊˈfaɪbrəl/
noun
  1. A very thin fiber or thread-like structure, especially in plant cell walls or animal tissues.
    • Under a microscope, you can see the microfibril network in the cell wall.
    • Cellulose microfibrils give plant stems their strength.
    • The microfibril arrangement affects how flexible a material is.