Fig. 3.

Morphology of chitosan droplets at the tip of the injection needle at various electric potentials. Chitosan solutions (2%) were ejected at 2 ml/h and the formation of droplets was monitored by a digital video camcorder at 30 fps. All images are presented in a single picture frame that the droplets is about to leave the needle at the electric potentials of a 0.0 kV, b 2.5 kV, c 5.0 kV, and d 10.0 kV. The dropping time at the lower table was determined by analyzing the between period of the microspheres dropping (n = 3)