Deposition of hydrogel particle impacting on smooth glass and porous nanofiber mat

Hydrogels are one of the most evolving areas in biopolymers engineering; with different composition, size, and morphology depending on the application field. However, a few is known on the dynamics of hydrogel particles impacting on a solid surface. In this research, an in-air microfluidics system was developed to generate hydrogel particles with an initial diameter of 343-478 mu m based on sodium alginate solution using calcium chloride as crosslinker and ethyl alcohol. The impact of hydrogel particles within the "beads-on-thread" flow structure on a homogeneous smooth glass and a heterogeneous porous nanofiber mat (scaffold) was studied to characterize deposition. For successive particle-surface and particle-particle collisions, empirical expressions were derived to determine the deposition parameters of a spreading/deformable hydrogel particle at Reynolds and Deborah numbers of 0.0003-0.002 and 0.19-0.22, respectively. Based on the expressions, the 3D printing technology concept was reported to demonstrate how to produce a honeycomb hydrogel 1-layered material with a set volumetric geometry. In addition, the parameters for the linear motion of a printing node with micronozzles were estimated. The study is motivated by the practical possibility of using multicomponent heterogeneous liquids with a complex internal structure in biomedical technologies to increase their functionality during deposition on a surface.