Micro helical polymeric structures produced by variable voltage direct   electrospinning
  Direct near field electrospinning is used to produce very long helical polystyrene microfibers in water. The pitch length of helices can be controlled by changing the applied voltage, allowing to produce both micro springs and microchannels. Using a novel high frequency variable voltage electrospinning method we found the helix formation speed and compared the experimental buckling frequency to theoretical expressions for viscous and elastic buckling. Finally we showed that the newmethod can be used to produce new periodic micro and nano structures. 
S. P. Shariatpanahi and A. Iraji zad and I. Abdollahzadeh and R.   Shirsavar and D. Bonn and R. Ejtehadi
cond-mat.soft cond-mat.mtrl-sci physics.bio-ph physics.flu-dyn q-bio.TO