Learn about electrospinning, the most used method for nanofiber fabrication and the factors affecting the quality of nanofibers.

1. By
Dhwani Jhala
Graduate student
Biomaterials & Biomimetics Laboratory

2. Historical Overview

5. Introduction
Grafts: Woven vs. Nonwoven
The nonwoven structure has unique
features:
• Interconnected pores
• Very large surface-to-volume ratio
• Enables nanofibrous scaffolds to
have many biomedical and
industrial applications.
(a) Woven fabrics
(b) Non-woven fabrics
(c) “Soldered” junctions
Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.

6. Electrospinning Setup
1. A high voltage power supply (normally
working in a range between 10 and
30kV);
2. A polymer reservoir that can maintain a
constant flow rate of solution, commonly
a syringe connected to either a
mechanical or a pneumatic syringe pump;
3. A conductive dispensing needle as
polymer source connected to the high
voltage power supply;
4. A conductive substrate, normally grounded, which serves as a collector for the
electrospun fibers.

8. Procedure
• An electrostatic potential is applied between a spinneret
and a collector
• A fluid is slowly pumped through the spinneret.
• The fluid is usually a solution where the solvent can
evaporate during the spinning.
• The droplet is held by its own surface tension at the
spinneret tip, until it gets electrostatically charged.
• The polymer fluid assumes a conical shape (Taylor cone).
• When the surface tension of the fluid is overcome, the
droplet becomes unstable, and a liquid jet is ejected
Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.

9. Setup

11. Materials that can be used

12. Aligned and cross-aligned fibers

13. Co-axial electrospinning

15. Solution concentration
Material variables

16. Molecular weight of polymer

17. Surface Tension

18. Voltage
Process variables

19. Distance

20. Flow rate

21. Temperature

22. Humidity

23. Applications