In 2008, Weitz et al. found that polymethylmethacrylate (PMMA) nanofibers could be collected at the edge of the spin-coater and this could be regarded as a prototype system to produce nanofibers for other polymers (as shown in Fig. 10.1). In their experiment, 5 wt% PMMA solution in chlorobenzene was placed in the middle of the chuck of a spin-coater and the chuck was subsequently rotated at a speed of 3000 rpm for a few seconds. As shown in Fig. 10.1, the nanofibers were formed at the end of the polymer fingers, which can be explained by a Rayleighe Taylor instability at the aireliquid interface.