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A dual‐field method is described to produce aligned fibers by electrospinning. By applying a secondary electric field perpendicular to the primary field, control over the orientation of the fibers on the collector is obtained. The dual‐field approach is used in conjunction with dual electrodes and a rotating collector. Both approaches were used to electrospin poly(lactic acid) fibers under conditions intended to produce fibers with a diameter greater then 400 nm to aid observation by optical microscopy and digital photography. Digital photography was used to visualize a large area of aligned fiber and image analysis software was used to quantify the degree of alignment. Fibers aligned with the aid of a dual field showed better alignment than those from a single electric field under otherwise identical conditions.magnified image

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Cover: The cover picture shows an electrospinning set-up having a second electric field applied perpendicular to the primary electric field. This is done in order to compress the bending pathway in one direction to assist alignment of the electrospun fiber as it deposits onto a collector. A digital photograph shows electrospun PLLA fiber collected onto a parallel electrodes collector, and a Fourier Transform image shows the quality of the alignment. Further details can be found in the article by M. Acharya, G. K. Arumugam,* and P. A. Heiden* on page 666.

Fabricating nano electrodes with a few nanometer inter-electrode gap laterally is a challenge with existing technologies. In this work, we present a simple method to fabricate electrode pairs with a sub-20 nm inter-electrode gaps using Focused Ion Beam (FIB) etching technology. Unlike previously reported methods, no internal or external modification in the Focused Ion Beam system is needed in this technique. An inter-electrode gap of 17 nm in a Cr electrode pair is successfully fabricated by optimizing the thickness of the Cr film. This fabrication technique is further applied to realize the source drain and gate electrodes with a targeted inter-electrode gap of 20 nm, for room temperature operating Single Electron Transistors.