with each and can phase segregate without the use of surfactants. This method can be simplified further if a solvent which dissolves both polymers is used. Melt electrospinning Electrospinning of polymer melts eliminates the need for volatile solvents in solution electrospinning. Semi crystalline polymer fibers such as PE, PET and PP, which would otherwise be impossible or very difficult to create using solution spinning, can be created. The setup is very similar to that employed in conventional electrospinning and includes the use of a syringe or spinneret, a high voltage supply and the collector. The polymer melt is usually produced by heating from either resistance heating, circulating fluids, air heating or lasers. Due to the high viscosity of polymer melts, the fiber diameters are usually slightly larger than those obtained from solution electrospinning. The fiber uniformity upon achieving stable flow rates and thermal equilibrium, tends to be very good. The whipping instability which is the predominant stage in which the fiber is stretched for spinning from solutions can be absent from the process due to the low melt conductivity and high viscosity of the melt. The most significant factors which affect the fiber size tend to be the feed rate, the molecular weight of the polymer and the diameter of the spinneret. Fiber sizes ranging from ~250 nm to several hundreds of micrometers have been created thus far with the lower sizes being achieved using low molecular weight polymers. History In the late 16th century William Gilbert set out to describe the behavior of magnetic and electrostatic phenomena. He observed that when a suitably electrically charged piece of amber was brought near a droplet of water it would form a cone shape and small droplets would be ejected from the tip of the cone: this is the first recorded observation of electrospraying. In 1887 C. V. Boys described “the old, but little known experiment of electrical spinning”. Boys’ apparatus consisted of “a small dish, insulated and connected with an electrical machine”. He found that as his stock liquid reached the edge of the dish, that he could draw fibers from a number of materials including shellac, beeswax, sealing-wax, gutta-percha and collodion. The process of electrospinning was patented by J.F. Cooley in May 1900 and February 1902 and by W.J. Morton in July 1902. In 1914 John Zeleny, published work on the behavior of fluid droplets at the end of metal