Electrospinning is a process by which sub-micron polymer fibers can be prod
uced using an electrostatically driven jet of polymer solution (or polymer
melt). Electrospun fibers are typically collected in the form of non-woven
mats, which are of interest for a variety of applications including semi-pe
rmeable membranes, filters, composite reinforcement, and scaffolding used i
n tissue engineering. A characteristic feature of the electrospinning proce
ss is the onset of a chaotic oscillation of the electrospinning jet. The cu
rrent work demonstrates the feasibility of dampening this instability and c
ontrolling the deposition of sub-micron polymer fibers (< 300 nm in diamete
r) on a substrate through use of an electrostatic lens element and collecti
on target of opposite polarity. Real-time observations of the electrospinni
ng process have been made using high-speed, high-magnification imaging tech
niques. Fiber mat!; and yarns electrospun from polyethylene oxide have been
analyzed using wide-angle X-ray diffraction (WAXD). optical microscopy, an
d environmental scanning electron microscopy (ESEM). (C) 2001 Published by
Elsevier Science Ltd.