Research Projects

The project seeks to develop a low cost and easily scalable method to fabricate monodisperse hydrogel beads. Hydrogel has emerged as a promising material for drug encapsulation and release, water harvesting, water filtration, and tissue engineering among others. The breadth of applications has motivated the community to explore and develop various fabrication methods to create hydrogels with good control over shape, size and porosity. Some of the popular methods in this regard are microfluidics, soft lithography, spray-drying and extrusion dripping. While these methods offer great control over hydrogel morphology and size, they are also inherently expensive, complex in setup and implementation and require considerable expertise. Thus, a fabrication/production scheme that is low-cost and yet is able to create hydrogel beads with good control over shape and size is very much an open research problem. In this project, I plan to develop and explore a drop impact-based scheme to create monodisperse hydrogels. It is important to first note that hydrogel forms when a base polymer material comes in contact with a cross-linking material that gives rise to an intricate 3D network of pores. Thus, the morphology of the polymer solution during cross-linking determines the final shape to a large extent. Thus, if the shape and size of the primary polymer drop is accurately controlled, it will also enable good control over the final hydrogel after cross-linking. Thus, the engineering objective here is to first design a scheme that generates polymeric drops with good repeatability and uniformity in size. Interestingly, impact of a drop on wire mesh or screens leads to the formation of several secondary drops with sizes in a wide range. My aim here is to control the impact process in such a way that every time a drop impacts the mesh, it results into a reduced size secondary drop from the other side of the mesh. This polymeric drop then falls into an aqueous pool of the cross-linking agent, resulting into the formation of monodisperse hydrogel beads. The project will explore various natural and synthetic polymers to fabricate hydrogels. Once the production step is satisfactorily implemented, I would label the hydrogel with fluorescent particles and then transfer them to a pure water pool to study the particle release profile, which is an important parameter for drug delivery applications. Next, I would develop mesh-reinforced hydrogel sheets with and test their performance for applications such as water harvesting, oil-water separation and tissue engineering.