Semester and Master Projects

Fall 2019

Flexible Composite Hydrogels

The good biocompatibility renders hydrogels well-suited biomaterials that are often used in biomedicine. In addition, hydrogels are used on the market as superabsorbent materials, wound dressings, and drug delivery systems. However, state-of-the-art applications of hydrogels are severely limited due to their poor mechanical properties. Novel strategies, such as developing double (DNs) or interpenetrating (IPNs) networks, promise to increase the versatility of hydrogels for load-bearing applications by combining polymeric networks with complementary characteristics. Stemming from this idea, the project aims at developing a bioinspired dually crosslinked hydrogel with superior mechanical properties which could be of great interest in the field of tissue engineering as replacement for damaged tendons or cartilage or as scaffold for cell growth.

In this project you will learn the basics of single and double network hydrogel fabrication. In parallel, you will gain experience in soft materials characterization techniques. In a more advanced stage of the project, you will investigate the effect of ions or nanoparticles infiltration on the resulting mechanical properties. If you are interested in the project, do not hesitate to contact me at matteo.hirsch@epfl.ch.

Growing crystals within emulsion drops

To control the size of crystals that grow in bulk solution is often challenging. To address this challenge, we useĀ  semi-permeable double emulsion drops of well-defined sizes to initiate the formation of crystals in their cores and to control their growth. In this project, you will learn how to produce and operate microfluidic devices to fabricate of double emulsions. You will lean how to initiate crystal formation in the cores of double emulsions and how to control their growth. You will investigate how the solute concentration and composition influences the size and structure of the resulting crystals. If you are interested, please contact aysu.okur@epfl.ch for further information.

Assembly of Drop-Based Hydrogels using Microfluidic Traps

Many natural materials have well-defined structures on different length-scales. Inspired by nature, we produce micro-granulated hydrogels with locally varying compositions to increase the mechanical properties. Such hydrogels can potentially be used for load-bearing applications, such as artificial tendons or other soft implants. To achieve this goal, we produce aqueous drops using microfluidics. These drops are assembled into superstructures and converted into granular hydrogels.

You will use microfluidic trapping devices to control the assembly of different types of drops in a microfluidic chip. Monomers contained in these drops are polymerized on-chip before the chamber is backfilled with a solution containing another polymer to produce hydrogels with locally varying compositions. You will learn how to fabricate and operate microfluidic devices and how the assembly of drops can be controlled using specially designed microfluidic devices. In addition, you will learn how to convert drops into hydrogels and how to characterize their mechanical properties with tensile tests. If you are interested, please contact michael.kessler@epfl.ch for further information.