Browsing by Subject "Atomic force microscopy"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Biofouling and Organic Fouling of Ultrafiltration and Reverse Osmosis Membranes: Quantification by Atomic Force Microscopy(2020-12) BinAhmed Menzies, SaraN/AItem Real time identification of local surface properties of material using atomic force microscope - An FPGA based implementation(2017-02) Pradhan, SouravSystem identification is widely employed for building mathematical models of manifold systems using statistical techniques. In this thesis, the application of system identification to atomic force microscopy using a real-time embedded solution has been reported. Atomic force microscopes are prevalent instruments utilized to explore material properties at the micro/nanometer level. A Field Programmable Gate Array has been chosen to harbor the design of the system identification module. The reported module has been successfully cascaded with an atomic force microscope to estimate local surface mechanical properties of materials. The design layout described in this thesis is not just applicable to commercially available atomic force microscopes, but to a large group of real-time signal processing units. Numerous simulations over multiple platforms and experimental results are presented to validate the accuracy and performance of the designed system identification module.Item Transverse shear microscopy: a novel microstructural probe for organic semiconductor thin films.(2010-08) Kalihari, VivekThe microstructure of ultrathin organic semiconductor films (1-2nm) on gate dielectrics plays a pivotal role in the electrical transport performance of these films in organic field effect transistors. Similarly, organic/organic interfaces play a crucial role in organic solar cells and organic light emitting diodes. Therefore, it is important to study these critical organic interfaces in order to correlate thin film microstructure and electrical performance. Conventional characterization techniques such as SEM and TEM cannot be used to probe these interfaces because of the requirement of conducting substrates and the issue of beam damage. Here, we introduce a novel contact mode variant of atomic force microscopy, termed transverse shear microscopy (TSM), which can be used to probe organic interfaces. TSM produces striking, high contrast images of grain size, shape, and orientation in ultrathin films of polycrystalline organic materials, which are hard to visualize by any other method. It can probe epitaxial relationships between organic semiconductor thin film layers, and can be used in conjunction with other techniques to investigate the dependence of thin film properties on film microstructure. In order to explain the TSM signal, we used the theory of linear elasticity and developed a model that agrees well with the experimental findings and can predict the signal based on the components of the in-plane elastic tensor of the sample. TSM, with its ability to image elastic anisotropy at high resolution, can be very useful for microstructural characterization of soft materials, and for understanding bonding anisotropy that impacts a variety of physical properties in molecular systems.