Friday, March 21, 2014 (4:15 – 5:15 p.m. in Yost 306)

Title: How To Build the Hydrogel Membrane Oscillator: Mathematical Model of Hydrogel Volume Phase Separation

Speaker: Lingxing Yao (Case Western Reserve University)

Abstract: Hydrogels are soft materials similar to natural tissue, and they can be found in applications such as food additives, contact lens, cosmetic surgery, wound healing and etc. Since hydrogels are made of cross linked polymer networks that are capable of absorbing large amounts of water, they can be present in swollen state in which 99% of the volume will be water, or they can be completely dry (collapsed state). Under proper physical and chemical conditions, we could observe the volume phase transition in hydrogels from swollen to collapsed state, and sometimes, repeatedly. In this presentation, we will discuss how to characterize the elastic, ionic and mixing energy in a membrane made of  hydrogel.
Based on these principles, we will describe the model (a system of ODEs) that is capable of explaining the oscillatory volume phase transition seen in a real membrane oscillator built in lab for drug delivery.