The process of Electro–Spinning has been known for almost 70 years. The first patent for this process was obtained by Formhals in 1934. Larrondo & Manley performed a similar work on polymer melts in 1981 followed by research by Reneker and Chun, who have  shown the possibility to electrospun a wide range of polymer solutions in 1996. From last two decades Ramakrishna, Zhang, Yoshimoto, Dalton, Kim and so many others are working on different aspects of electrospinning.

The conventional fibre spinning techniques for the manufacture of filaments yarns and man-made fibers are Wet Spinning, Dry Spinning, Melt Spinning and Gel-Spinning. These technologies are capable of producing polymer fibers with diameters down from “mm” (10-3m) to (µm) micro meter 10-6 m Range.

Electrospinning or electrostatic spinning is a process capable for producing polymer fibers in nano meter (10-9) diameter range.

Variables of Electro – Spinning

The variables of Electro spinning which must be controlled effectively and accurately are listed below:

• Polymer solution variables such as molecular weight and its distribution as well as architecture (branded, linear). Furthermore the solution properties such as viscosity, conductivity, surface tension and volatility (evaporation) are important parameters.
• Process variables for Electro-Spinning of Nano-Fibers include electrical potential, flow rate of Polymer, distance between capillary & target and ambient parameters of chamber (such as temperature, humidity, air velocity).

End–Uses of Nano-Fibers

Some of the end uses are self cleaning cosmetic skin masks, skin therapy with medicine, protective clothing for military personnel for anti-bio chemical gases and efficient aerosol trapping and filter media for liquid and gas filtration.

Industrial application includes photovoltaic devices such as nano solar cells, micro and nano electronic devices, LCD devices and other application in electromagnetic interference shielding. In medical textiles, the nano  technology is used for tissue engineering scaffolding. Examples include porous membrane for skin grafting, tubular shapes for blood vessels and nerve regeneration and also 3 D scaffolds for bone and cartilage regeneration.

Another very interesting facet of nano technology is application in thermal sensors, piezo electronic sensors, biochemical sensors and fluorescence optical chemical sensors.