PROPERTIES AND APPLICATIONS OF ELECTROSPUN FIBERS
Electrospinning is the process by which an electrically forced elongational fluid jet produces solid fibers. The strong elongational flow in the jet can induce a significant degree of molecular orientation in the resulting fibers, and can also be used to orient and stretch isolated molecules and particles embedded within the jet and resulting fibers. After a brief introduction to electrospinning, I begin with a description of the direct measurement of the velocity profile in an electrospinning jet using particle image velocimetry, and then discuss measurement of the molecular orientation in individual electrospun fibers using polarized Raman micro-spectroscopy. Individual suspended fibers were also characterized using atomic force microscopy to measure their Young?s moduli. I then discuss applications of electrospinning, including the use of electrospinning jets to stretch and embed isolated DNA molecules and the use of sacrificial electrospun fibers to produce nanochannels for fluidic applications. Finally, I conclude with novel electrospinning system designs, including a system that uses electric fields to steer an electrospinning jet and an automated electrospinning source using microfabricated nozzles for improved deposition.
dissertation or thesis