Degree Name

Doctor of Philosophy


Intelligent Polymer Research Institute


Implantable electrode devices, such as implantable metal electrodes, are important for treating neural disorders and brain diseases. However, the mechanical compliance between the stiff metal and soft brain tissue causes long-term inflammation associated with glial scar formation, which is detrimental to both the surrounding tissue and performance of the electrode. To address this mechanical mismatch, hydrogels with similar properties to human brain tissue can provide a mechanically compliant, ‘biomimetic’ interface. Therefore, in this thesis, we incorporated a hydrogel layer on a thin film conducting polymer electrode as a model system to study the properties of the hydrogel and its interactions with living cells, including in the presence of an electrical field. A central theme of the thesis was to improve our understanding of the physical interactions between the hydrogel and human neural stem cells. This question was especially of interest since cell integration and adhesion to an electrode surface, in this case the hydrogel, is very important for many neurotechnologies such as implantable electrodes, microelectrode arrays and electronic cell culture substrates. While studies on cellhydrogel interactions are rapidly increasing, one aspect that remains unexplored is the direct measurement of the forces that a cell ‘experiences’ when interacting with the hydrogel, particularly at the molecular level. Hence, the project employed the use of an approach based on Atomic Force Microscopy (AFM), termed Single Cell Force Spectroscopy (SCFS), to enable direct measurement of single cell adhesion on the hydrogel. Lastly and importantly, many of the experiments were designed to consider the dynamic changes of the hydrogel properties in response to electrical stimulation by implementing in-situ electrochemical capabilities.



Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.