| The future of nanotechnologies depends on the successful development of versatile, low-cost techniques for patterning micro- and nanoarchitectures. While most approaches to nanofabrication have focused primarily on making periodic structures at ever smaller length scales with an ultimate goal of massively scaling their production, I have focused on introducing control into relatively disordered nanofabrication systems. Well-ordered patterns are increasingly unnecessary for a growing range of applications, from anti-biofouling coatings to light trapping to omniphobic surfaces. The ability to manipulate disorder, at will and over multiple length scales, starting with the nanoscale, can open new prospects for textured substrates and unconventional applications. Taking advantage of previously considered defects; I have been able to develop nanofabrication techniques with potential for massive scalability and the incorporation into a wide range of potential application. This thesis first describes the manipulation of the non-Newtonian properties of liquid Ga and Ga alloys to confine the metal and metal alloys in gratings with sub-wavelength periodicities. Through a solid to liquid phase change, I was able to access the superior plasmonic properties of liquid Ga for the generation of surface plasmon polaritons (SPP). The switching contract between solid and liquid Ga confine in the nanogratings allowed for reversible manipulation of SPP properties through heating and cooling around the relatively low melting temperature of Ga (29.8 °C). The remaining chapters focus on the development and characterization of an all polymer wrinkle material system. Wrinkles, spontaneous disordered features that are produced in response to compressive force, are an ideal for a growing number of applications where fine feature control is no longer the main motivation. However the mechanical limitations of many wrinkle systems have restricted the potential applications of wrinkled surfaces. We developed a wrinkle material system that could be both tuned in feature size from as small as 30 nm up 10 ?m while maximizing the wrinkle amplitude at all wavelengths. By charactering the material properties of both the skin and substrate, we were able to generate wrinkle patterns with fine control over periodicity, amplitude, and orientation. The final chapters of this thesis focuses on the transfer of the wrinkle structure into functional materials aimed at manipulating biological adhesion of cells, optical absorption of solar cells, and sensor sensitivity of Raman substrates. The success of these applications was directly relative to the capabilities of our wrinkle system in controlling the surface chemistry, tuning the periodicity, and maximizing the amplitude for each application. |
