A versatile AFM local oxidation lithography was developed for fabricating clean protein patterns ranging from nanometer to sub-millimeter scale on octadecyltrichlorosilane (OTS) layer of Si (100) wafer. This protein patterning method can generate bio-active protein pattern with a clean background without the need of the anti-fouling the surface or repetitive rinsing. As a model system, lysozyme protein patterns were investigated through their binding reactions with antibodies and aptamers by AFM. Polyclonal anti-lysozyme antibodies and anti-lysozyme aptamer are found to preferentially bind to the lysozyme molecules on the edge of a protein pattern before their binding to the interior ones. It was also demonstrated that the topography of the immobilized protein pattern affects the antibody binding direction. We found that the anti-lysozyme antibodies binding to the edge lysozyme molecules on the half-buried pattern started from the top but the binding on the extruded pattern started from the side because of their different spatial accessibility. In addition, after incubating lysozyme pattern with anti-lysozyme aptamer in buffer solution for enough long time, some fractal-shaped aptamer fibers with 1-6nm high and up to tens of micrometers long were formed by the self-assembling of aptamer molecules on the surface. The aptamer fibers anchor specifically on the edge of protein patterns, which originates from the biospecific recognition between the aptamer and its target protein. Once these edge-bound fibers have formed, they can serve as scaffolds for further assembly processes. We used these aptamer fibers as templates to fabricate palladium and streptavidin nanowires, which anchored on the pattern edges and never cross over or collapse over each other. The aptamer fiber scaffold potentially can lead to an effective means to fabricate and interface nanowires to existing surface patterns.

Inorganic based membranes which have a symmetric/asymmetric structure have been produced using an immersion induced phase inversion and sintering method. An organic binder solution (dope) containing yttria-stabilised zirconium (YSZ) particles is spun through a triple orifice spinneret to form a hollow fibre precursor, which is then sintered at elevated temperatures to form a ceramic support. The phase inversion process for the formation of hollow fibre membranes was studied in order to produce the best morphological structure/support for palladium based membranes. The spinning parameters, particle size, non-solvent concentration, internal coagulant as well as the calcination temperature were investigated in order to determine the optimum values. Sintering temperature was also investigated, which would yield a sponge-like structure with an optimized permeability, while retaining a smooth outer surface. The supports produced by phase inversion were characterized in terms of dimension by mercury porosimetry, compressed air permeability, Surface Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The morphology of the produced ceramic support showed either dense or porous characteristics governed by the dynamics of the phase inversion process. The particle size of YSZ was examined in order to decrease the amount of agglomerates in the spinning suspension. Zetasizer tests indicated that at 15 minutes, the ultrasonic bath effectively homogenised the YSZ particles and prohibited soft agglomerates from reforming in the spinning suspension. In this study, an increase in air gap had no noticeable effect on the finger like voids but it had a considerable effect on both the inner diameter (ID) and outer diameter (OD) of the green fibres, while an increase in bore liquid flow rate and extrusion pressure promoted viscous fingering and significant effect on the ID and OD of the fibres, respectively. There was a decrease in porosity and permeability with increasing sintering temperature, addition of water concentration in the spinning suspension and varying Nmethylpyrrolidone (NMP) aqueous solution of the internal coagulant. The amount of YSZ added to the starting suspension influenced the properties of the support structure. Viscous deformation was observed for dope with lower particle loading thus resulted in the formation of cracks and defects during sintering. / >Magister Scientiae - MSc

Visco-elastic behaviour at the nano-level of a commonly used polymer (PET) is characterised using atomic force microscopy (AFM) at a range of temperatures. The modulus, indentation creep and relaxation time of the PET film (thickness = 100 m) is highly sensitive to temperature over an experimental temperature range of 22¿175 ¿C. The analysis showed a 40-fold increase in the amount of indentation creep on raising the temperature from 22 ¿C to 100 ¿C, with the most rapid rise occurring above the glass-to-rubber transition temperature (Tg = 77.1 ¿C). At higher temperatures, close to the crystallisation temperature (Tc = 134.7 ¿C), the indentation creep reduced to levels similar to those at temperatures below Tg. The calculated relaxation time showed a similar temperature dependence, rising from 0.6 s below Tg to 1.2 s between Tg and Tc and falling back to 0.6 s above Tc. Whereas, the recorded modulus of the thick polymer film decreases above Tg, subsequently increasing near Tc. These visco-elastic parameters are obtained via mechanical modelling of the creep curves and are correlated to the thermal phase changes that occur in PET, as revealed by differential scanning calorimetry (DSC).

Indiana University-Purdue University Indianapolis (IUPUI) / A new process for fabricating a nano fluidic device that can be used in medical application is developed and demonstrated. Nano channels are fabricated using a nano tip in indentation mode on AFM (Atomic Force Microscopy). The nano channels are integrated between the micro channels and act as a filter to separate biomolecules. Nano channels of 4 to7 m in length, 80nm in width, and at varying depths from 100nm to 850 nm allow the resulting device to separate selected groups of lysosomes and other viruses. Sharply developed vertical micro channels are produced from a deep reaction ion etching followed by deposition of different materials, such as gold and polymers, on the top surface, allowing the study of alternative ways of manufacturing a nano fluidic device. PDMS (Polydimethylsiloxane) bonding is performed to close the top surface of the device. An experimental setup is used to test and validate the device by pouring fluid through the channels. A detailed cost evaluation is conducted to compare the economical merits of the proposed process. It is shown that there is a 47:7% manufacturing time savings and a 60:6% manufacturing cost savings.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20361号 / 工博第4298号 / 新制||工||1666(附属図書館) / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 安達 泰治, 教授 小寺 秀俊, 教授 田畑 修 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

no / Low frequency (0.1¿2 Hz) dynamic mechanical analysis on individual type I collagen fibrils has been carried out using atomic force microscopy (AFM). Both the elastic (static) and viscous (dynamic) responses are correlated to the characteristic axial banding, gap and overlap regions. The elastic modulus (¿5 GPa) on the overlap region, where the density of tropocollagen is highest, is 160% that of the gap region. The amount of dissipation on each region is frequency dependent, with the gap region dissipating most energy at the lowest frequencies (0.1 Hz) and crossing over with the overlap region at ¿0.75 Hz. This may reflect an ability of collagen fibrils to absorb energy over a range of frequencies using more than one mechanism, which is suggested as an evolutionary driver for the mechanical role of type I collagen in connective tissues and organs. / BBSRC

no / Following traumatic injury, skin has the capacity to repair itself through a complex cascade of biochemical change. The dermis, which contains a load-bearing collagenous network structure, is remodelled over a long period of time, affecting its mechanical behaviour. This study examines the nanomechanical and viscoelastic properties of the upper dermis from human skin that includes both healthy intact and scarred tissue. Extensive nanoindentation analysis shows that the dermal scar tissue exhibits stiffer behaviour than the healthy intact skin. The scar skin also shows weaker viscoelastic creep and capability to dissipate energy at physiologically relevant frequencies than the adjacent intact skin. These results are discussed in conjunction with a visual change in the orientation of collagenous fibrils in the scarred dermis compared with normal dermis, as shown by atomic force microscopy imaging.

Reservoir characterization is an essential step in the oil/gas exploration process and is of great significance in the evaluation of oil/gas resources. To evaluate the production potential of the Lower Huron shale in the central Appalachian Basin, matrix permeability, Raman spectroscopy, Fourier Transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) were used in this study. According to the experimental results, matrix permeability is relatively high for a shale gas formation, suggesting great production potential of shale gas resources in this region. Additionally, four shale samples with varying thermal maturity were characterized by the complementary Raman and FTIR spectroscopy, and curve-fitting results successfully demonstrated the change of chemical structures with the evolution of thermal maturity. Raman spectroscopy results show that the curve fitted G band position and the band separation between the G band and D1 band tend to increase with the rise of thermal maturity level. Results of FTIR spectroscopy show that the aromaticity level and the condensation extent of aromatic rings show an increasing tendency with the increase of maturation level. Moreover, mechanical properties of these four shale samples were characterized by AFM. Results show that Young's modulus is in the range of 8.20 GPa - 12.94 GPa, which is in the normal range compared with the results from other shale formations. Additionally, scanned results show an increasing tendency for Young's modulus of the organic components with the rise of thermal maturity level in these shale samples. The potential reason for this phenomenon was also explored, specifically, the growth of aromatic groups and the decrease of the CH2/CH3 ratio may be possible reasons for the rise of Young's modulus of organic components in these shale samples. This work is meaningful for the evaluation of shale gas resources, especially emerging plays, in the central Appalachian Basin, and it also provides a valuable database for relevant research on shale matrix permeability, Raman, FTIR and AFM. / Master of Science / Reservoir characterization is important in evaluating the production potential of unconventional resources. The purpose of this work is to characterize key reservoir properties of shale samples from the central Appalachian Basin to provide support for improved shale gas production in this region. This work includes the analysis of matrix permeability testing, Raman and Fourier Transform infrared spectroscopy (FTIR) characterization, and atomic force microscopy (AFM) mapping. Matrix permeability testing results show that the matrix permeability of these six samples is relatively high for a shale gas formation, suggesting great production potential of shale gas resources in this region. Additionally, four shale samples with different thermal maturity were scanned using Raman and FTIR spectroscopy, and mineral components of these same four samples were also identified by the FTIR analysis. Processed Raman data show that two important measures, the G band position and the difference between the G band position and D1 band position, tend to increase with the rise of thermal maturity. FTIR results show that the aromaticity rings would likely be compressed due to the increased number of aromaticity rings. Also, AFM provides a high-resolution map for the Young's modulus, a measure of material stiffness, of these four samples. The modulus value is in the normal range compared with scans from other shale formations. In addition, the modulus value tends to increase with the increase of thermal maturity level. The increase of aromatic rings and the decrease of the CH2/CH3 ratio can be regarded as potential reasons for the change of modulus value. This work has potential to improve the production design of shale gas resources, especially emerging plays, in the central Appalachian Basin and can be regarded as a valuable reference for other similar research.

Neste trabalho, se pretende caracterizar a morfologia de filmes finos poliméricos por meio de técnicas de processamento de imagens, utilizando principalmente a geometria computacional e técnicas de classificação de padrões. Os objetivos principais foram quantificar as grandezas geométricas das estruturas observadas nos filmes finos e descrever padrões de superfície formados nestes filmes. Foram estudadas imagens obtidas por microscopia de força atômica (AFM) de amostras de filmes finos SEBS [poliestireno-poli(etileno-co-butileno)-poliestireno], depositados sobre um substrato de mica por técnicas de imersão. Os filmes finos SEBS são considerados de grande interesse devido à formação de estruturas auto-organizadas na escala nanométrica. A caracterização e a obtenção da morfometria dos filmes são de relevância neste trabalho, pois contribuem para o entendimento da dinâmica de formação destes padrões nas nanoestruturas estudadas. Foram analisadas diferentes morfologias, como forma de gotículas com anéis concêntricos e forma de tiras e pontos regularmente espaçados. Os resultados obtidos permitem caracterizar os padrões observados. / In this work, we intend to characterize the morphology of polymer thin films by techniques of image processing, mainly using computational geometry and pattern classification. The main objectives were to quantify the geometrical structures observed in thin films and describe surface patterns formed in these films. Were studied images obtained by atomic force microscopy (AFM) of SEBS [polystyrene-poly(ethylene-co-butylene)-polystyrene] thin films samples, deposited on a mica substrate by dip-coating technique . SEBS thin film polymers have great interest due to the formation of self-organized structures on the nanometer scale. The characterization and obtaining measurements of the morphology of the thin films are of relevance in this work, because they contribute to the understanding of the formation dynamics of these patterns in nanostructures studied. We analyzed different morphologies, such as droplets form with concentric rings and stripe and regularly spaced points forms. The results allow to characterize the observed patterns.

In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.