Microelectromechanical structures (MEMS) are used commercially in sensor applications and in recent years much research effort has been done to implement them in wireless communication. Electron beam lithography and other advancements in fabrication technology allowed to shrink the size of MEMS to nanomechanical systems (NEMS). Since NEMS are just a couple of 100 nm in size, highly integrated sensor applications are possible. Since NEMS consume only little energy, this will allow continuous monitoring of all the important functions in hospitals, in manufacturing plants, on aircrafts, or even within the human body. This thesis discusses the modeling of NEM resonators. Loss mechanisms of macroscale resonators, and how they apply to NEM resonators, will be reviewed. Electron beam lithography and the fabrication process of Silicon NEM resonator will be described. The emphasis of this work was to build a test setup for temperature dependant measurements. Therefore different feasible techniques to detect nanoscale vibration will be compared and the setup used in this work will be discussed. The successful detection of nanoscale vibration and preliminary results of the temperature dependence of the quality factor of a paddle resonator will be reported. A new approach to fabricate NEM resonator using electrofluidic assembly will be introduced. / Master of Science

In the extreme environment of space, radiation induced health issues is a major concern. The ability to induce higher levels of free radicals and reactive oxidative species (ROS) are factors to be addressed. Ceria nanoparticles (CNPs) can provide a means to scavenge ROS through regenerative redox coupling that occurs on the surface and acts as a radioprotectant. Additionally, the defect levels in CNP can be categorized by the Ce3+/Ce4+ ratio with a high ratio indicating superoxide scavenging, a radical species with high oxidative potential. However, engineering a specialized Ce3+ NP often requires a harsh reducing agent. We hypothesized a wet-chemical synthesis utilizing both reducing and non-reducing sugars to engineer stable CNPs with high Ce3+ state. This sustainable process uses simple sugars to ensure high biocompatibility while maintaining the specific vacancy density found in Ce3+ dominant CNP. X-Ray photoelectron spectroscopy (XPS) show that the reducing sugars allows for nearly 70/30 Ce3+/Ce4+ ratio compared to non-reducing sugars. This high Ce3+/Ce4+ ratio of CNPs can be useful in scavenging ROS in space radiation applications. In addition, typical drug molecules utilize biopolymers which can increase ROS under the ionizing radiation environments found in space. To improve the drug viability, we hypothesized CNPs conjugated to drugs as a viable solution. Current results indicate high Ce3+ structural confirmation of ceria nanoparticles using a wet-chemical synthesis. The synthesized nanoparticles were then conjugated with risedronate, a third-generation bisphosphonate. Microwave radiation studies indicated that CNP was able to be used as a radioprotectant as it prevented changes in drug chemistry as detected by UV/Vis spectra after exposure to microwave radiation. Finally, in vitro human mesenchymal stem cell results from alkaline phosphatase (ALP) and Alizarin red S (ARS) assays, suggest potential for the conjugates to differentiate cells. The mechanism for radioprotective ability can be attributed to the high Ce3+ state.

Yes / The peptide sequence GrBP5, IMVTESSDYSSY, is found experimentally to bind to graphene, and ex situ atomic force microscopy indicates the formation of an ordered over-layer on graphite. However, under aqueous conditions neither the molecular conformations of the adsorbed peptide chains, nor the molecular-level spatial ordering of the over-layer, has been directly resolved. Here, we use advanced molecular dynamics simulations of GrBP5, and related mutant sequences, to elucidate the adsorbed structures of both the peptide and the adsorbed peptide over-layer at the aqueous graphene interface. In agreement with a previous hypothesis, we find GrBP5 binds at the aqueous graphene interface chiefly via the tyrosine-rich C-terminal region. Our simulations of the adsorbed peptide over-layers reveal that the peptide chains form an aggregate that does not evolve further into ordered patterns. Instead, we find that the inter-chain interactions are driven by hydrogen bonding and charge–charge interactions that are not sufficiently specific to support pattern formation. Overall, we suggest that the experimentally-observed over-layer pattern may be due to the drying of the sample, and may not be prevalent at the solvated interface. However, our simulations indicate sequence modifications of GrBP5 to promote over-layer ordering under aqueous conditions.

Technology is the ‘engine of economic growth’ and technological progress is the most important factor driving a nation’s sustained economic growth. New technologies assume significant and long term role in this process of economic development. New technologies can trigger new cycles of economy, provide windows of opportunity for less developed countries to catch up with the more advanced nations and are important from the wealth creation point of view. However for this to happen, the technology should be able to reach society in the form of new products, processes. Nanotechnology is a new and emerging technology that can play important role to promote India’s economic development. Wide ranges of applications are claimed for nanotechnology and it is considered to be the next big wave of technology after information technology and biotechnology. Government of India has started a mission on nanoscience and nanotechnology in May 2007 with an allocation of ~ 200 million USD for 5 years. However, if one looks at the ‘Nanotechnology’ from the wealth creation point of view, then, research efforts alone in this field, are not sufficient. The research efforts should lead to new products, new processes, and new platforms. Management of technology can assume significant role in this process. It is generally agreed upon that management of nanotechnology is necessary to create economic advantage at the national level. However, the macro level understandings namely, policy at the national level, must result in ground level organization performance. In order to facilitate innovation in the field of NST (Nanoscience and Technology), the process of innovation in this field must be well understood. Infrastructure and management of R&D is a key aspect and entrepreneurship is vital for the development of a new technology. The aim of this study is to do the assessment of nanoscience and nanotechnology initiatives in India. Emerging technology assessments for nation building to meet societal objectives is an extremely complex task. Challenge lies in understanding complex R&D requirements and likely innovations at the lab level. Further challenge lies in assessing initiatives of the start-ups, individual entrepreneurs and comparing them with the Government research initiatives. Understanding the resource requirements of different research initiatives in the field of nanoscience and nanotechnology (NST) will greatly assist in facilitating innovation in this field. Further understanding of human, cultural issues, education and training aspects, technical and market uncertainties faced by nanoscience and nanotechnology research initiatives will be an added advantage for the policy makers to facilitate innovation in the field of nanoscience and nanotechnology (NST). Review of Literature A critical literature review in the field of Technology Management; Innovation, Technological Innovation; and nanoscience and nanotechnology from a business perspective gave researcher a strong foundation to define nanotechnological innovation and understand the process of nanotechnological innovation. This literature along with the literature on the emergence of a new industry helped identify factors that would facilitate innovation in the field of nanoscience and nanotechnology. While understanding importance of management in developing nanotechnology to realize its benefits, no study has attempted to link the management processes with the innovation output in the field of nanoscience and nanotechnology. Also, there are very few empirical studies in this area. Thus need to empirically determine various management processes that can facilitate innovation in the field of nanoscience and nanotechnology and their causal relatedness to output measures of innovation in the field of nanoscience and nanotechnology is identified as a research gap. Aims, Objectives This study aims at conceptualizing the challenges of developing appropriate framework for assessment of emerging technologies in a particular domain. It further aims to use this framework for assessing nanoscience and nanotechnology initiatives in India and to come up with set of alternatives for policy makers at the national level. The objectives are 1. To develop a framework for the assessment of a new technology initiative with a view to enable innovation in the field of nanoscience and nanotechnology. This further gave rise to two objectives viz, a. Measure the innovation in the field of nanoscience and nanotechnology. b. Identify factors that enable innovation in the field of nanoscience and nanotechnology. 1 To use developed framework to assess nanoscience and nanotechnology initiatives in India. 2 To make suggestions for effective institution building and develop interventions for efficient management of nanoscience and technology research and development initiatives. Conceptual Model The conceptual model links two major aspects viz., output of innovation and factors facilitating innovation in the field of nanoscience and nanotechnology (NST). This model is used as a tool to assess nanoscience and nanotechnology initiatives in India. Output of innovation is measured at three levels, namely, Focused NST initiative -an initiative where with clear goals, deliverables and resources work on NST project has started. Newness of NST initiative -which measures generation of new products, new processes in the field of NST and Dissemination of NST initiative -which measures publications and patents in the field of NST. Factors facilitating innovation include Organization context, presence of Basic resources, Leadership, Strategic research partnerships, Link with venture capitalists, Technology characteristics and Innovation culture. These factors were thought to be positively linked with the output of innovation in the field of nanoscience and nanotechnology. Methodology Based on a critical literature review, a preliminary study entailing in-depth interviews with strategy experts and a pilot study, a structured questionnaire was developed, to measure constructs and variables in the conceptual model. The main study consisted of data collected from 112 researchers from private as well as public organizations engaged in nanoscience and nanotechnology research and development. Results and Discussion The first part of the analysis began with factor analysis. Based on the factor loadings 31 factors were obtained. These factors were considered to be facilitating innovation in the field of nanoscience and nanotechnology. Similarly output of innovation in the field of NST got loaded onto 3 factors, namely Focused NST initiative, Newness of NST initiative and Dissemination of NST initiative. Non-Hierarchical K-means (K = 2) cluster analysis resulted in two useful clusters among respondents; Cluster 1 primarily represented academic institutes whereas, Cluster 2 mainly represented private sector start-ups in the field of nanoscience and nanotechnology. Factors facilitating innovation and output of innovation were compared across two clusters of the organizations. The student’s t-test was used to compare means of factor scores and items under it across two clusters. Based on the statistical significance of the difference between the factor scores across two clusters, conclusions were drawn as to whether the presence of factors facilitating innovation and output of innovation differ across academic institutes and private sector start-up firms. Significant differences were obtained between the two clusters of organizations with respect to availability of finance, technical and industrial experience of the leadership, strategic research partnerships, market uncertainty and link with the venture capitalists. Output of innovation also differed across two types of organizations, wherein, academic institutes were more active in producing “dissemination” output of innovation and private start-up firms are more active in producing “newness” output of innovation. The next stage of analysis dealt with finding out what among these factors actually contribute to innovation in the field of nanoscience and nanotechnology. Multiple linear regression technique was used to for this purpose. Thus, for three levels of innovation output, three regression models are obtained. Industrial experience of the leaders, Finance, Market readiness of the products are some of the factors facilitating ‘Newness’ output of innovation, whereas, Academic experience and Link with the technical communities are some of the factors affecting Dissemination of NST Initiative. The next stage of analysis dealt with simultaneous estimation of dependent variables. Structural equation modeling in the form of path analysis (AMOS software from SPSS) was used for this purpose. This also helped in explaining how different variables (dependent as well as independent) are related to each other. At an aggregate level, causal model could be fitted between factors facilitating innovation and output of innovation in the field of nanoscience and technology. Chi-square, Normed Fit Index (NFI) and Root mean square error analysis (RMSEA) were the measures used to accept the model. Path analysis also helped to find significant covariances among the independent variables. Concomitant with the quantitative approach of data analysis, qualitative approach using case study was also used to assess nanoscience and nanotechnology initiatives in India. Case study was conducted in two different types of organizations; a premier academic institution and a private start-up firm. Case study revealed that private sector organizations indeed struggle to raise finance. However, high entrepreneurial attitude motivates these young engineers. In case of academic institutions it was noted that in an academic environment there is no real motivation for commercialization or taking research to the market. Performance and rewards for faculty depend to a large extent on publications and to a very small extent on patents. Culture of industrial R&D is not very strong in India and not many companies are willing to experiment. Major conclusions of the study Major conclusions of the study pointed out differences between academic institutes and private start-up firms with respect to availability of the resources, leadership of the people, strategic research partnerships. It also pointed out differences in the types of output of innovation produced by these two firms. Causal analysis in the form of regression and path analysis pointed out factors actually contributing to innovation in the field of nanoscience and nanotechnology. Case study analyzed qualitatively challenges faced by researchers from academic institutes and private start-up firms. Major Suggestions to organizations From the data analyzed in the study, it can be seen that private sector firms in India are facing the problem of raising finance as compared with academic institutions. Similarly, analysis of the data shows, significantly less Industry – Government interactions as compared with Academic institutions – Government interactions. Understanding the importance of private industries in developing applications of new technologies, Government needs to come out with appropriate practices to build a good “ecosystem” for nanotechnology innovation. At the national level, efforts are undertaken by the Government to increase and encourage research initiatives in the field of nanoscience and nanotechnology. Substantial investment can be made in developing technology managers and also build technology entrepreneurs who would commercialize the products and build new products from the new technology. Thus, formation of start-up firms can be encouraged. This will absorb the manpower trained by academic research institutes and will enhance technical and market experience among researchers which was noted as a important factor for enhancing ‘newness’ output of innovation. Detailed analysis of various programs initiated by Government of India does show presence of various mechanisms to promote private sector initiatives in field of nanoscience and nanotechnology. However, present study shows that the private sector is finding it difficult to raise finance through various Government schemes. Academic sector is the major beneficiary of Government funding however, the research results stop at publications in these organizations. Private sector is able to bring new products, new processes, however, struggles to raise finance. Thus private sector start-ups could be funded with Government funding mechanisms. These mechanisms can be made less cumbersome for the start-up firms. Academic sector on the other hand should be encouraged by way of incentives for generation of new products. Considering importance of strategic research partnerships, institutional mechanisms could be put into place which will enhance Government – Industry and Industry-Academia research interaction. Contribution of the study The main contribution of this study includes, a conceptual model involving resource based view of innovation. The conceptual model is further used for measuring output of innovation in the field of nanoscience and nanotechnology (NST) at three levels, namely newness of NST initiative, dissemination of NST initiative and having a focused NST research initiative. Factors which may promote and facilitate innovation in the field of nanoscience and nanotechnology (NST) are also measured. Comparison is made across different types of organizations to see availability of these enabling factors in Indian nanoscience and nanotechnology initiatives. Using regression analysis and path analysis, factors which actually contribute to innovation in the field of NST are identified. The main implication of the study is towards a better policy formulation in strengthening human resources, organizational capability, increasing funding for research and enhancing academic – industry interaction for better innovative performance. Limitations of the study The present study does not include all the types of organizations in the technology environment, this includes, namely nanoscience and nanotechnology R&D initiatives in large sized organizations and Government research organizations like Defense research and Development Organization (DRDO), Indian Space research Organization (ISRO). These organizations were contacted for data collection for this study, however they denied permission. Directions for future research Present study involved cross section of researchers engaged in the field of nanoscience and nanotechnology. Future studies can be longitudinal that can track changes in leadership, organizational structure and organizational processes. This study provides a conceptual model that can be used for the assessment of other new technologies in India e.g. defence or manufacturing related technologies.

Ruthenium oxide (RuO2) nanorods are an emergent technology in nanostructure devices. As the physical size of electronics approaches a critical lower limit, alternative solutions to further device miniaturization are currently under investigation. Thin-film nanorod growth is an interesting technology, being investigated for use in wireless communications, sensor systems, and alternative energy applications. In this investigation, self-assembled RuO2 nanorods are grown on a variety of substrates via a high density plasma, reactive sputtering process. Nanorods have been found to grow on substrates that form native oxide layers when exposed to air, namely silicon, aluminum, and titanium. Samples were analyzed with Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques. Conductive Atomic Force Microscopy (C-AFM) measurements were performed on single nanorods to characterize structure and electrical conductivity. The C-AFM probe tip is placed on a single nanorod and I-V characteristics are measured, potentially exhibiting rectifying capabilities. An analysis of these results using fundamental semiconductor physics principles is presented. Experimental data for silicon substrates was most closely approximated by the Simmons model for direct electron tunneling, whereas that of aluminum substrates was well approximated by Fowler-Nordheim tunneling. The native oxide of titanium is regarded as a semiconductor rather than an insulator and its ability to function as a rectifier is not strong. An electronic model for these nanorods is described herein.

Respiratory Syncytial Virus (RSV) is a potentially life-threatening respiratory pathogen that infects approximately 64 million children and immunocompromised adults globally per year. Currently, there is a need for prophylactic and therapeutic approaches effective against primary and secondary RSV infections. This project focuses on the development of a simple, smart, and scalable anti-RSV nanotherapeutic that combines novel cellular antiviral defense mechanisms targeting the inhibition of viral fusion and replication. An ICAM-1 targeted liposomal nanocarrier will be synthesized and coated with a layer of chitosan containing the anti-fusion HR2-D peptide as an extracellular defense mechanism. Additionally, chitosan complexed to dual expressing short hairpin RNA (shRNA) recombinant plasmids will be encapsulated within the nanocarrier, and provide an intracellular defense mechanism that will interfere with the expression of the NS1 and P proteins. In combination, both defense mechanisms are expected to induce a synergistic anti-RSV effect that will surpass those of conventional therapeutics. Through this research, the NS1 and P containing plasmid (pSH-NS1-P) was cloned, and the nanotherapeutic was successfully synthesized. Based on the acquired results, pSH-NS1-P was shown to express anti-RSV effects, and it was also concluded that both inserts were producing active shRNA. Additionally, the anti-RSV efficiency of HR2-D was confirmed. Overall, this research will lead to development of a dual-mechanistic anti-viral nanotherapeutic.

This thesis is centered on the Gadonanotubes (GNTs), an ultra-high-performance magnetic resonance imaging (MRI) contrast agent material discovered in our laboratories in 2005. The GNTs are a new paradigm in MRI contrast agent design with small clusters of Gd3+ ions within ultra-short carbon nanocapsules (ca. 50 nm) cut from full-length single-walled carbon nanotubes. Here, the factors underlying the performance efficacy of the GNTs have been investigated for the first time by variable-field (-50,000 Oe to 50,000 Oe at 2K) and variable-temperature (2K to RT at 100 Oe) magnetic susceptibility measurements using a Magnetic Property Measurement System (MPMS, based on a SQUID magnetometer). Additionally, experiments focused on the effects of hydroxylation of the GNTs’ exterior surface regarding water-solubility are examined. Finally, the use of the GNTs as potential replacements for traditional metal-chelating/sequestering agents is explored. More specifically, the internal Gd3+-ion clusters of the GNTs have been radiolabeled: (1) with 153Gd3+ ions to test Gd3+-ion stability to simulated biological challenge, (2) with 225Ac3+ ions to generate a new concept for a GNT-based agent for α-radiotherapy, and finally (3) with 64Cu2+ ions to produce the first bimodal MRI/PET (PET = positron emission tomography) imaging agent derived from the GNTs.

Motivated by a desire to understand the basic concepts of one-dimensional nanostructure growth, the research described in this thesis aims at understanding the basic mechanisms controlling the synthesis and formation of a specific group of II-VI semiconducting nanostructures. In particular, this thesis examines one-dimensional nanostructures (such as nanobelts and nanowires) and different morphologies of ZnS that result from the interesting properties that the materials have at the nanoscale. In order to understand how to tune these properties in the nanostructure, it is necessary to have an understanding of the growth mechanism that dictates the morphology, structure, and rate of growth of the nanomaterial. It is necessary to understand what impact changes to the macroscopic setup in the experiment have on the nanoscopic scale of the nanomaterials. Having a larger understanding and exerting more precise control over the growth of nanomaterials will allow a higher level of selectivity, more control over dimensionality and the type of morphology, easier manipulation, and the simpler incorporation of these structures into a nanotechnological device. The main focus of the research was on CdSe and ZnS, with the bulk of the research being conducted on ZnS nanostructures. These materials were chosen for their potential for extensive research, their possible applications in optoelectronics, their potential to form the wurtzite crystal structure, and the potential generalization of results to other nanomaterials. The framework for the research is given first. Then a description of the experimental setup and a model for the growth of nanostructures is discussed. A brief overview of the synthesis of CdSe nanostructures is given and then a detailed analysis of the synthesis of specific ZnS one-dimensional morphologies is presented.

Silver nanoparticles (AgNP), the most popular nano-compounds, possess unique chemical, physical and biological properties. Albizia adianthifolia (AA) – rich in saponins – is a plant of the Fabaceae family, found abundantly on the East coast of Africa. This plant is well known for its medicinal properties, and although the exact phytochemistry of AA is unknown, recent research suggests that AA can be used for the treatment of certain pathologies. The biological properties of a novel silver nanoparticle (AAAgNP) synthesised from an aqueous leaf extract of AA, were investigated on A549 lung carcinoma cells. Cell viability was determined by the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Cellular oxidative status (lipid peroxidation and glutathione (GSH) levels) were determined by the TBARS and GSH-Glo™ Glutatione assays respectively. ATP concentration was measured using the CellTitre-Glo™ assay. Caspase-3/-7, -8 and -9 activities were determined by Caspase-Glo® assays. Flow cytometry was used to measure apoptosis, mitochondrial (mt) membrane depolarisation, expression of CD95 receptors and intracellular smac/DIABLO levels. DNA fragmentation was assessed with the comet assay. The expression of p53, bax, PARP-1 and smac/DIABLO was evaluated by western blotting. Quantitative polymerase chain reaction was used to determine mRNA levels of bax and p53. AAAgNP caused a dose-dependent decrease in cell viability with a significant increase in lipid peroxidation (5-fold vs. control; p=0.0098) and decreased intracellular GSH (p=0.1184). A significant 2.5-fold decrease in cellular ATP was observed upon AAAgNP exposure (p=0.0040) with a highly significant elevation in mt membrane depolarisation (3.3-fold vs. control; p<0.0001). Apoptosis was also significantly higher (1.5-fold) in AAAgNP treated cells (p<0.0001) with a significant decline in expression of CD95 receptors (p=0.0416). AAAgNP caused a significant 2.5-fold reduction in caspase-8 activity (p=0.0024) with contrasting increases in caspase-3/-7 (1.7-fold vs. control; p=0.0180) and -9 activity (1.4-fold vs. control; p=0.0117). Western blots showed increased expression of smac/DIABLO (4.1-fold) in treated cells (p=0.0033). Furthermore, AAAgNP significantly increased the expression of p53, bax cleaved PARP-1 (1.2-fold; p=0.0498, 1.6-fold; p=0.0083 and 1.1-fold; p=0.0359 respectively). The expression of mRNA for both p53 and bax was also elevated post AAAgNP treatment, with 6-fold (p=0.0036) and 5-fold (p=0.0080) changes respectively compared to untreated cells. Data suggests that AAAgNP induces cell death in the A549 lung cells via the mt-mediated intrinsic apoptotic program. Further investigations are required to assess the potential use of AAAgNP in cancer treatment. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.

abstract: The objective of this dissertation is to study the use of metamaterials as narrow-band and broadband selective absorbers for opto-thermal and solar thermal energy conversion. Narrow-band selective absorbers have applications such as plasmonic sensing and cancer treatment, while one of the main applications of selective metamaterials with broadband absorption is efficiently converting solar energy into heat as solar absorbers. This dissertation first discusses the use of gold nanowires as narrow-band selective metamaterial absorbers. An investigation into plasmonic localized heating indicated that film-coupled gold nanoparticles exhibit tunable selective absorption based on the size of the nanoparticles. By using anodized aluminum oxide templates, aluminum nanodisc narrow-band absorbers were fabricated. A metrology instrument to measure the reflectance and transmittance of micro-scale samples was also developed and used to measure the reflectance of the aluminum nanodisc absorbers (220 µm diameter area). Tuning of the resonance wavelengths of these absorbers can be achieved through changing their geometry. Broadband absorption can be achieved by using a combination of geometries for these metamaterials which would facilitate their use as solar absorbers. Recently, solar energy harvesting has become a topic of considerable research investigation due to it being an environmentally conscious alternative to fossil fuels. The next section discusses the steady-state temperature measurement of a lab-scale multilayer solar absorber, named metafilm. A lab-scale experimental setup is developed to characterize the solar thermal performance of selective solar absorbers. Under a concentration factor of 20.3 suns, a steady-state temperature of ~500 degrees Celsius was achieved for the metafilm compared to 375 degrees Celsius for a commercial black absorber under the same conditions. Thermal durability testing showed that the metafilm could withstand up to 700 degrees Celsius in vacuum conditions and up to 400 degrees Celsius in atmospheric conditions with little degradation of its optical and radiative properties. Moreover, cost analysis of the metafilm found it to cost significantly less ($2.22 per square meter) than commercial solar coatings ($5.41-100 per square meter). Finally, this dissertation concludes with recommendations for further studies like using these selective metamaterials and metafilms as absorbers and emitters and using the aluminum nanodiscs on glass as selective filters for photovoltaic cells to enhance solar thermophotovoltaic energy conversion. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2018