Guided Fiber Deposition

In this concept, the key is to draw the electrospinning jet to a desired location instead of controlling the electrospinning jet path right from initiation. The electrospinning jet may take a longer path thereby allowing greater stretching of the solution. This will overcome the limitation of the stable jet technique where the distance between the jet initiation and fiber deposition may be too short to allow sufficient fiber stretching.

Experiments have shown that the electrospinning jet can be directed towards a sharp edge or point [Teo et al 2005, Theron et al 2001, Sundaray et al 2004, Baede 2009, Solberg 2007]. In an experiment by Theron et al, the electrospinning jet was shown to spread out over a large area as it leaves the spinneret but converge to the edge of a disc collector [Theron et al 2001]. Using high speed camera and depositing polyethylene oxide fiber on the flat surface of a rotating disc, Solberg (2007) was able to capture the image of a straight jet hitting the mylar disc close to where the end of a thin wire was positioned under the disc. Thus, there is evidence to suggest that the electrospinning jet may break off from the bending instability path and be directed to deposit close to the guiding electrode. It is likely that combining this concept with a stable spinning jet will give rise to more precise fiber deposition. The stable jet will allow the user to bring jet sufficiently close to the guiding electrode such that it can bring the jet to the final deposition location. Gupta et al used a combination of near-field electrospinning and a point guiding electrode behind a flat plate collector to improve the precision of the electrospinning process. A square grid with width of 250 microns was constructed to demonstrate the level of precision made possible using this technique [Gupta et al 2007]. Other researchers have also demonstrated the ability to guide the electrospinning jet towards a collector using a sharp pin guiding electrode behind a class cover [Sundaray et al 2004 , Baede 2009, Solberg 2007].