Thiol-ene Nanostructuring

Abstract: Improving the health and well-being of humankind does not only constitutepart of our moral codes, but is also enlisted as the number three goal ofthe 2030 agenda for sustainable development set by the UN. Fulfilling suchobjective in the regions of resource-poor settings or for age groups with morevulnerability to infectious agents demands immediate actions. This has necessitatednovel ways of rapid and ultra-sensitive diagnostics to provide compactand affordable systems, e.g. for an early detection of bacteria and viruses.The fields of bio-micro/nanoelectromechanical systems (BioMEMS/NEMS)and lab-on-a-chip (LoC) have been founded based on such demands, butcritically challenged by problems partly associated with manufacturing andmaterial domains and biosensing methods. The fabrication methods for theminiaturization of features and components are often complicated and expensive,the commonly used materials are typically not adaptable to industrialsettings, and the sensing mechanisms are sometimes not sensitive enough forthe detection of lowly-concentrated samples.In this thesis, new methods of ultra-miniaturization, as well as conventionalcleanroom-based techniques, for nanopatterning of well-defined topographiesin off-stoichiometry thiol-ene-(epoxy) polymers are presented. In addition,their use for several sensing applications has been demonstrated. Thefirst part of the thesis gives an introduction to the field of BioMEMS/NEMS.The second part of the thesis presents a technical background about theprevalent methods of polymer micro- and nanofabrication, implementationof the resulting polymer structures for different sensing applications, alongwith the existing challenges and shortcomings associated with state of theart. The third part of the thesis presents e-beam nanostructuring of thiol-eneresist, for the first time, achieving the smallest and densest features reportedin these polymer networks. The thiol-ene-based polymer also represents anovel class of e-beam resist resulting in structures with reactive surface nature.The fourth part of the thesis demonstrates the use of thiol-ene-epoxysystems for nanoimprint lithography and further shows the structuring ofhigh-aspect-ratio and hierarchical topologies via single-step UV-NIL. The fifthpart of the thesis introduces Micro- and NanoRIM platforms for scalable andoff-cleanroom manufacturing of microfluidic devices and nanostructuring ofmaterials in thiol-ene (-epoxy) systems. The sixth part of the thesis exhibitsthe implementation of the noted nanofabrication methods for differentBioMEMS/NEMS applications including protein nanopatterning, simultaneousmolding and surface energy patterning, ultra-sensitive digital biosensing,and facile quartz crystal microbalance (QCM) sensor packaging.