MAGNETIC FLUID

In 2004, Yarin and Zussman reported a needle-less electrospinning system that used a magnetic field to initiate the jet formation. The setup comprised a bottom layer of ferro magnetic fluid and an upper layer of polymer solution (Fig. 7.4A). When an external magnetic field was applied to the fluid system and an electric field was added simultaneously to the polymer solution layer, the ferromagnetic fluid triggered the formation of steady vertical spikes, which perturbed at the interlayer interface. Under the action of a strong electric field, these spikes were drawn into fine solution jets (Fig. 7.4B). Compared with multineedle electrospinning, this needle-less setup can produce polyethylene oxide (PEO) nanofibers with 12 times higher productivity. Nevertheless, the nanofibers electrospun are relatively coarser with larger diameter distribution.