Hendrickson, Grant R. ; Lyon, L. Andrew Chemistry and Biochemistry Perry, Joseph W. Dickson, Robert M. Janata, Jiri Wartell, Roger M. Lyon, Louis A. ; Lyon, L. Andrew
Hydrogel materials have become a heavily studied as materials for interfacing with biology both for laboratory investigations and the development of devices for biomedical applications. These polymers are water swellable and can be made responsive to many different stimuli by choice of monomers, co-monomers, and cross-linkers or functionalization with pendent ligands, substrates, or charged groups. The high water content, low moduli and potential responsively of these polymers make good candidates for biomaterials. A specific type of hydrogel called a microgel or a hydrogel micro/nanoparticle has similar properties to bulk hydrogel materials. Many of the interesting results and utility of the microgels in bioapplications are due to their inherent softness of the material. Here, the softness, flexibility, and conformability of these water swollen particles is used to create an interesting sensor platform, studied in the context of a microgel passing through a pore, and used as an emulsifier to create a drug delivery platform. The unifying theme of this dissertation is the softness of microgels which is critical for all of these experiments. However, the study of individual microgel softness is challenging and complex, since the softness is composed of two different components. The first is that the microgel is a swollen polymer which can be deswollen by an external stimuli or force. The second is that the microgel is a volume conserving elastic colloid which can deform without deswelling under the certain conditions. Throughout, this dissertation will discuss the ramifications of the complex softness of microgels in each experimental result and potential application.