Conjugated polymer surface switches for active cell control

Sammanfattning: Conjugated polymers have been found useful in a wide range of applications such as sensors, electrochemical transistors, solar cells, and printed electronics due to their mechanical, optical and electronic properties. An amazing research field has grown during the last three decades since the discovery of conducting polymers in 1976. Since the materials can be made from solutions, different processing methods such as spin coating and vapor phase polymerization can be used to coat a huge variety of substrates. The choice of method depends mainly on monomer solubility and kind of substrate to be coated. During the synthesis the polymers can be chemically modified to tailor their functionalities. Due to this variability in materials and the processability, electronics can be achieved on unconventional substrates such as flexible plastic foils and cell culturing dishes. As a contrast to inorganic, usually metallic materials, conducting polymers are built up from organic compounds in a molecular structure with soft mechanical properties that have shown to be a benefit in combination with biology, ranging from interactions with cells to interactions with advanced biological species such as tissues. This combination of research fields and the possible applications are merged within the field of organic bioelectronics.The primary purpose of this thesis is to give a background to organic electronics in general and how electrochemical devices can be processed and developed for biological applications in particular. An organic electronic surface switch is introduced to control cell adhesion and proliferation as well as an electrochemical transistor to spatially tune the cell adhesion along an electrochemical gradient. To mimic a more natural cell environment a three dimensional fiber substrate was used to design an electronically active matrix to promote nerve cell adhesion and communication. By combining standard microfabrication techniques and conjugated polymers desired patterns of electroactive polymer were created to enable active regulation of cell populations and their extracellular environment at high spatial resolution. Finally, a brief look into future challenges will also be presented.