Conventional electrospinning produces randomly ordered nanofibers, however many potential applications require precisely defined morphology and anisotropic properties of nanofibrous materials. In this work, a collector consisting of two segments has been used to prepare uniaxially ordered nanofibers. Optimized collector design comes from both analytical calculations of electrostatic strength in the vicinity of the electrodes and from experimental verification by polyvinyl alcohol nanofibers fabrication. The transversal electric strength is a key factor in achieving very well aligned nanofibers. The results presented here help provide a better understanding of the electrically induced alignment mechanism. (C) 2010 American Institute of Physics. [doi:10.1063/1.3430507]