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In recent years, nanostructured and amorphous metals have become more prominent in scientific research. Their unique characteristics and their vastly superior mechanical properties have lead to emerging technical applications however the use of these materials is only in its infancy. To further growth the industrial applications for these advanced materials, joining processes capable of maintaining the unique aspects of the microstructure are required. / Joining of two beveled plates has been accomplished by use of the Cold Spray process. This process uses a converging diverging nozzle to accelerate micron sized powder towards a substrate. The strength of the resulting joint has been compared to freeforms made of powder of the same composition. No significant difference was observed in the mechanical properties between the freeforms and the weldments and examination of the fracture surface showed that the strength of the interface is higher than the strength of the freeform itself. / A weld repair experiment has also been performed where the ElectroSpark Deposition process (ESD) has successfully been used to transfer amorphous material from an electrode to an amorphous substrate without crystallizing either material. This result is of crucial importance as it signifies that these extremely expensive and heat sensitive materials can be repaired when in-service wear causes damage. This process, due to its inherently fast cooling rate, has also successfully been used to transform a crystalline AlCoCe alloy into an amorphous deposit atop both amorphous and crystalline substrates.

Influenza is the infectious agent of the seasonal flu. Flu symptoms from influenza infection are similar to the symptoms caused by bacterial upper respiratory tract infections. This similarity causes the inappropriate diagnosis and prescription of antibiotics, leading to drug resistant bacterial strains. Moreover, the limitations of the current viral detection methods prevent the clinical diagnosis of influenza. The objective of this project is to design a rapid and sensitive influenza diagnostic method based on the highly sensitive Nanostructured microelectrode biosensing assay. The diagnostic method was designed by selecting probe sequences, controlling the quality of the probes and the sensing chips, and optimizing the deposition conditions. This diagnostic method was shown to be capable of differentiating influenza sequences from non-complementary sequences, detecting influenza sequences in the form of ~1000-nucleotide RNA molecules, sensing the target influenza RNA within a complex mixture of cell lysates, and achieving a clinically relevant detection limit.

Influenza is the infectious agent of the seasonal flu. Flu symptoms from influenza infection are similar to the symptoms caused by bacterial upper respiratory tract infections. This similarity causes the inappropriate diagnosis and prescription of antibiotics, leading to drug resistant bacterial strains. Moreover, the limitations of the current viral detection methods prevent the clinical diagnosis of influenza. The objective of this project is to design a rapid and sensitive influenza diagnostic method based on the highly sensitive Nanostructured microelectrode biosensing assay. The diagnostic method was designed by selecting probe sequences, controlling the quality of the probes and the sensing chips, and optimizing the deposition conditions. This diagnostic method was shown to be capable of differentiating influenza sequences from non-complementary sequences, detecting influenza sequences in the form of ~1000-nucleotide RNA molecules, sensing the target influenza RNA within a complex mixture of cell lysates, and achieving a clinically relevant detection limit.

Bulk nanostructured silver components were fabricated from nano-sized powder using a shockwave consolidation technique. The grain size evolution during compaction, the mechanical properties of the bulk components, and the effect of surface finish on the mechanical behavior were studied. X-Ray diffraction, transmission electron microscopy (TEM), atomic force microscopy (AFM), microhardness, compression testing and shear punch testing at room temperature were used to characterize the materials. Upon consolidation, the average grain size calculated from image analysis of the TEM micrographs was 49+/-22 nm, showing the feasibility of maintaining a nanostructure upon dynamic consolidation. The hardness of the bulk nanostructured components was constant across the diameter with an average of 83+/-1 HV. Compression results showed strength about 390+/-10 MPa and ductility of 23+/-2%, which is well above strength level obtainable from strain hardened Ag components. The AFM results show that samples possessing a surface roughness of 267 nm exhibited a brittle behavior and a reduction in strength of 35% when compared to the smoother surfaces. Dimples were observed for the samples exhibiting plasticity, while an intergranular pattern was identified for the brittle materials. Fracture toughness of 0.2 MPa m was calculated, which confirms the strong relationship between fracture toughness and defects observed in nanomaterials.

In this thesis, high temperature vapor deposition method has been extensively used to synthesize nanomaterials. One of the as-synthesized nanostructures is superlattice-structured nanohelix, which is made of two types of alternating and periodically distributed long crystal strips. The manipulation of the nanohelix showed super-elasticity and special fracture mechanism. The other widely studied nanomaterial is vertically aligned ZnO nanowire array, which is epitaxially grown on GaN and SiC substrates. Several manipulation methods such as e-beam lithography (EBL), dielectrophoresis, and in situ direct manipulation, have been developed, so that the mechanical and electrical properties of a single nanowire can be characterized, which provide essential references for fabricating bridged nanowire based devices. Specifically, an improved atomic force microscope (AFM) based method has been developed to accurately measure the elastic modulus of bridged ZnO nanowires. Bridged nanostructure is an extremely important configuration in planar MEMS/NEMS devices and this new approach provides insights to the importance of boundary conditions. Novel physical and statistical models have been firstly developed to obtain better estimate of elastic modulus. For electrical properties of bridged nanowires, it is found that the direct contact of ZnO nanowire and Au electrodes displays a back-to-back Schottky behavior. Self-assembled monolayer (SAM) can improve the mechanical contact and increase the conductance. These devices with Schottky contacts show much better UV sensing performance than the ones with Ohmic contacts. Barrier height change is believed to play an important role in a lot of sensors. A thermionic emission-diffusion model is deduced to successfully explain the current change in a strain sensor. This thesis clearly exhibits the unique properties of ZnO nanomaterials and provides deeper understanding to methodologies as well as the phenomena. With further exploration, ZnO nanomaterials should be able to better understood and utilized, and come close to the next step of commercialization.