Electrospinning

Electrospinning is a fabrication technique that uses electrostatic forces to produce ultrafine fibers from polymer solutions or melts. A high-voltage power supply charges a liquid at the tip of a spinneret, typically a needle. When the electrostatic force overcomes surface tension, a Taylor cone forms and a thin jet is ejected, undergoing whipping instabilities as it travels to a grounded collector where it solidifies into continuous fibers. The process yields nonwoven mats with nanoscale to micrometer-diameter fibers and high porosity.

A standard setup includes a syringe pump, a metallic needle or spinneret, a high-voltage supply, and a collector (flat plate or rotating drum). Two main modalities exist: solution electrospinning, using a polymer in a volatile solvent, and melt electrospinning, using a polymer melt to avoid solvents. Variants such as coaxial, multi-jet, and needleless configurations enable core–shell structures and higher throughput.

Critical parameters are laboratory and material dependent. They include polymer solution properties (viscosity, conductivity, surface tension), process conditions (voltage, flow rate, tip-to-collector distance), and ambient factors (temperature, humidity). Proper tuning controls fiber diameter, morphology, alignment, and porosity.

Applications span tissue engineering scaffolds, wound dressings, filtration membranes, protective textiles, sensors, catalysis, and energy storage devices. Advantages include the ability to produce ultra-fine, high-surface-area fibers with controllable porosity and architecture. Limitations involve the use of organic solvents in many systems, safety considerations for high voltage, environmental concerns, and scale-up challenges for industrial production.

Materials used range from polymers such as poly(lactic acid), polycaprolactone, poly(vinyl alcohol), and polyurethanes to inorganic and composite precursors prepared via sol-gel or blending approaches. The technique has evolved from early 20th-century developments to widespread modern research and applications.