Parametric analysis of shape changes of alginate beads

In this article, the various elements controlling the geometry of alginate beads such as voltage, solution concentrations and extrusive rates were experimentally investigated. The findings indicated that the combination of higher voltages more concentrated CaCl2 solutions, shorter width of electrical field and slower extrusive rates can permit the alginate beads to become smaller. Also the effect of the electrical forces that acted on the liquid droplets was found to be stronger than that of the gravity forces did. The alginate solution concentration was found to influence the beads' shape significantly. Lower concentration of 0.5% resulted in tear-like beads arrangements and a higher concentration of 5 and 8% produced pear-like and sperm-like beads configurations. In addition to obtain special alginate beads, such as elliptical and bullet like beads, outside force could be applied. The above findings could open a broad gate for future control release system developments.

Graphical AbstractThis article concentrated on the discovery of alginate beads with different shapes. In order to obtain this goal, impact factors, such as concentration of alginate solution, acceleration voltage and outside force etc. were employed and investigated. Then, pear like (a), sperm like (b), elliptical (c), bullet like (d) and tear like (e) alginate beads were observed compared with regular view (f).Figure optionsDownload as PowerPoint slideResearch Highlights
► Illustrating viable/visible ways to construct various shapes of ALG beads.
► The shape changes of alginate beads are controllable.
► Achieving elliptical and bullet-like shapes sodium citrate were employed to collect Ca2+ from ALG hydrogel (which made it soft again) and subsequently the outside forces were applied.
► Various shapes of ALG beads which could be used as drug carrier, cell vector and capsule templates.