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Showing 1 to 20 of 20 for “"tapping mode atomic force microscopy"”.
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Nonlinear Dynamics of Tapping Mode Atomic Force Microscopy
A mathematical model is developed to investigate the grazing dynamics of tapping mode atomic force microscopes (AFM) subjected to a base harmonic excitation. The nonlinear dynamics of the AFM microcantilever are studied in both of the monostable and bistable phases with the microcantilever tip …
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Cantilever Dynamic Analysis in Tapping Mode Atomic Force Microscopy
Tapping mode atomic force microscopy (AFM) is becoming popular in the area of biology, as well as for polymer and semiconductor materials science. Unlike other AFM techniques, it only makes intermittent contact with the sample, which largely reduces any potential surface damage to soft materials, …
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Non-Smooth Dynamics and Control of Tapping Mode Atomic Force Microscopy
… to a linear impacting oscillator, and a dynamic model of tapping-mode atomic force microscope ensures persistence of the grazing solution trajectory by preventing loss of stability through a discontinuity induced saddle-node bifurcation.
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Design and implementation of cantilever probe holder for tapping mode atomic force microscopy
… novel cantilever probe holder that is capable of tapping mode operation. The probe holder is implemented in a previously designed high-speed, large-range atomic force microscope (AFM). This AFM used a cantilever probe holder that was only capable of contact mode operation, placing limitations on …
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Exploring the Nonlinear Dynamics of Tapping Mode Atomic Force Microscopy with Capillary Layer Interactions
Central to tapping mode atomic force microscopy is an oscillating cantilever whose tip interacts with a sample surface. The tip-surface interactions are strongly nonlinear, rapidly changing, and hysteretic. We explore numerically a lumped-mass model that includes attractive, adhesive, and repulsive …
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Mechanical behavior of ultrastructural biocomposites
… phase of biomacromolecules. High resolution microscopy imaging was employed to investigate the microscale features of seashell nacre to reveal the nucleation points within tablets, the sector boundaries and an overlap between tablets of neighboring layers of [approx.] 20 %. Aragonite, the …
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Admicellar Polymerization Of Calcium Carbonate And Its Performance In Drilling Fluids
… using Fourier Transform Infra-red (FTIR) or Tapping mode Atomic Force Microscopy (AFM). Nevertheless, application testing of low-polymer content admicellar polymerized CaCO 3 in drilling fluids shoincrease in mud viscosity and yield point with improved fluid loss control.
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Nano-contact printing of DNA monolayers
… surface coverage was analyzed using tapping mode atomic force microscopy (AFM). The percent coverage of oligonucleotide was then calculated from the tapping mode AFM phase images. Two general trends were found. The oligonucleotide surface coverage on the master increased slightly, …
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Mapping of elastic modulus and hardness in Trochus niloticus seashell nacre by nanoindentation
… hardness for the indent areas were generated. Tapping mode Atomic Force Microscopy was performed on the indented nacre after a treatment of surface etching, which revealed the tablet boundaries in order to correlate qualitatively the topographical features with the properties distribution. The …
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DC magnetron reactive sputtering of low stress AlN piezoelectric thin films for MEMS application
… of the sputtered AIN films was assessed using tapping mode atomic force microscopy and scanning electron microscopy. Energetic particle bombardment of the growing film surface helped to yield dense crystalline films with zone T microstructure. Thermalization of the impinging particle flux …
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Novel Fluorous Hybrid Surface Modification Characterized by Wetting Dynamics, Morphology and Nanomechanics
… by X-ray Photoelectron Spectroscopy (XPS) and Tapping Mode Atomic Force Microscopy (TM-AFM) respectively. Contrast in phase images reflect the surface modulus and viscoelasticity, from which physical form or compositional differences may be deduced. These characteristics have also been explored …
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Synthesis and Characterization of Multiblock Copolymer Proton Exchange Membranes for High Temperature Fuel Cell Applications
… mechanical and electrochemical properties under moderate operating conditions (e.g., < 80 ºC), their performance at high temperature (e.g., > 80 ºC) and low relative humidity (RH) drastically deteriorates. To overcome these problems, PEM materials with enhanced properties are essential. Recently, …
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Synthesis and Characterization of Multiblock Copolymers for Proton Exchange Membrane Fuel Cells (PEMFC)
… block length was longer than 6,000 g/mol (6k). Tapping mode atomic force microscopy (AFM) also showed clear nanophase separation between the hydrophilic and hydrophobic domains and the influence of block length, as one increased from 6k to 10k. Transparent and creasable films were solvent-cast …
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Synthesis and Properties of Novel Triptycene-containing Segmented Polyurethanes and Semicrystalline Polysulfone-polyester Multiblock Copolymers
… flexible hard segments with confirmation from tapping mode atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). The flexible HDI can be used to overcome the bulkiness of triptycene, promote microphase separation, and enhance mechanical properties. Novel PTMG based soft …
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Characterization of nanoscale electronic materials using novel methods for scan probe microscopy
… thesis we will explore several scan probe based microscopy techniques capable of mapping changes in electronic properties with sub-diffraction spatial resolution. Using novel methods for scan probe based microscopy, we combined electrical and morphology mapping to reveal structural driven …
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Synthesis and Characterization of Disulfonated Poly(Arylene Ether Sulfone) Random Copolymers as Multipurpose Membranes for Reverse Osmosis and Fuel Cell Applications
… (6FPPO), and poly(vinylidene fluoride) (Kynar®). Tapping mode atomic force microscopy (TM-AFM) images of the membranes with 10 wt% of fluorinated copolymers showed macroscopic phase separation. Good miscibility between the copolymers at low concentrations was also confirmed by the observation of …
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Investigation of the Influence of Selected Variables on the Solid State Structure-Property Behavior of Segmented Copolymers
… importance of the hydrogen bonding network in model polyurethaneurea copolymers was also explored by utilizing LiCl as molecular probe. It has been demonstrated that hydrogen bonding plays an important role, over and above microphase separation, in promoting the long-range connectivity of the …
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Synthesis and Characterization of methylene bis (p-cyclohexyl isocyanate)-poly (tetramethyl oxide) based Polyurethane Elastomers
… 80° and 60°, respectively. Results from force-distance curves with flamed glass slides obtained before and after immersion of the polyurethane coatings indicated that no water contamination occurred. Tensile tests demonstrated that hard block percentage, soft block molecular weight, and …
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Fundamentals of heat transfer and thermal-mechanical control for improved atomic force microscopy
This dissertation presents novel atomic force microscope (AFM) cantilevers and cantilever technology that improve the measurement rate and precision of AFM. AFM cantilevers with integrated heater-thermometers can generate and sense heat flows to measure and manipulate matter at the nanometer scale. …