Biomedical Engineering Reference
In-Depth Information
75
50
25
0
2002
2003
2004
2005
2006
Year of publication
FIGURE 5.1 Number of Pubmed publications over the past 5 years relevant to electrospinning as scaffold
fabrication method.
FIGURE 5.2 A typical random mat-like structure of micro- and nanometer-sized polymeric fi bers obtained
by electrospinning process.
to a spinneret (small orifi ce, or fl at-tipped needle) facing an earthed target, or collector. Upon reach-
ing a critical voltage, the surface tension of the polymer at spinneret tip is counterbalanced by
localized charges generated by the electrostatic force, and the droplet elongates and stretches into
a (Taylor) cone where a continuous jet is ejected. ( Safety note : Such high applied voltages need to
be safety protected and should only deliver low currents since an exposure to high amperages may
result in death.)
A schematic description of the electrospinning process is shown in Figure 5.3. Initially, the
polymer jet travels toward the target, but statistical perturbations result in some deviation from the
most direct path to the collector. As a charged entity moving across an electric fi eld, a force that is 90°
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