  Disordered fiber networks are ubiquitous in a broad range of natural (e.g.,
cytoskeleton) and manmade (e.g., aerogels) materials. In this paper, we discuss
the emergence of topological floppy edge modes in these fiber networks as a
result of deformation or active driving. It is known that a network of straight
fibers exhibits bulk floppy modes which only bend the fibers without stretching
them. We find that, interestingly, with a perturbation in geometry, these bulk
modes evolve into edge modes. We introduce a topological index for these edge
modes and discuss their implications in biology.
