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Full-Text Articles in Engineering

Design, Fabrication, And Testing Of A High-Speed, Low-Cost Atomic Force Microscope Housing And Distance Measurement System, Jonathan Menke Jan 2021

Design, Fabrication, And Testing Of A High-Speed, Low-Cost Atomic Force Microscope Housing And Distance Measurement System, Jonathan Menke

All Undergraduate Theses and Capstone Projects

Advances to the state-of-the-art in fields like biology and material science often stand on the foundation of improved imaging. Here a low-cost Atomic Force Microscope (AFM) housing and distance measurement system was designed, fabricated, and tested. The instrument was developed around an Optical Pickup Unit (OPU) and designed for use as part of a high-speed AFM system. A structure to align the OPU with the probe holder was designed to ensure the beam of the OPU is positioned above the probe in addition to accommodating space, manufacturability, and cost constraints by using cost effective components. The designs were fabricated and …


Fouling And Aging In Membrane Filtration : Hybrid Afm-Based Characterization, Modelling And Reactive Membrane Design, Wanyi Fu May 2019

Fouling And Aging In Membrane Filtration : Hybrid Afm-Based Characterization, Modelling And Reactive Membrane Design, Wanyi Fu

Dissertations

Membrane filtration has been extensively used in water and wastewater treatment, desalination, dairy making, and biomass/water separation. However, membrane fouling, aging and insufficient removal efficiency for dissolved organic matters remain major challenges for wider industrial applications. In order to tackle these challenges, this doctoral dissertation investigates mechanisms of membrane fouling and development of antifouling membrane filtration technologies. Specifically, four major research areas are explored: (i) nanoscale physicochemical characterization of the chemically modified polymeric membranes; (ii) quantitative modelling between membrane properties and membrane fouling and defouling kinetics; (iii) development of quantitative structure-activity relationships for membranes that undergo thermal and chemical aging …


Experimentally Validated 3d Md Model For Afm-Based Tip-Based Nanomanufacturing, Rapeepan Promyoo Dec 2016

Experimentally Validated 3d Md Model For Afm-Based Tip-Based Nanomanufacturing, Rapeepan Promyoo

Open Access Dissertations

In order to control AFM-based TBN to produce precise nano-geometry efficiently, there is a need to conduct a more focused study of the effects of different parameters, such as feed, speed, and depth of cut on the process performance and outcome. This is achieved by experimentally validating a MD simulation model of nanomachining, and using it to conduct parametric studies to guide AFM-based TBN. A 3D MD model with a larger domain size was developed and used to gain a unique insight into the nanoindentation and nanoscratching processes such as the effect of tip speed (e.g. effect of tip speed …


Measurement Of Activity And Stability Of Physical Vapor Deposition (Pvd) Coated Crystal Surfaces, Anuradha Krishnan Dec 2016

Measurement Of Activity And Stability Of Physical Vapor Deposition (Pvd) Coated Crystal Surfaces, Anuradha Krishnan

Masters Theses

The overall objective of this research work is to investigate the hydrophilic and hydrophobic forces acting on organic crystal planes and understanding the interaction of functional groups with additive molecular nanolayers. Crystals of acetaminophen and lactose were made and the surface forces were tested on Atomic Force Microscope (AFM). Uniformity of crystal surface was confirmed from the AFM study in the first stage. The growth factors of crystal planes as a function of time were studied. Adhesion forces on plain crystals were measured on both two different organic crystals made of acetaminophen and lactose. In the second stage, …


Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta Jul 2015

Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta

Mechanical & Aerospace Engineering Theses & Dissertations

The atomic force microscope (AFM) is a probe-based microscope that uses nanoscale and structural imaging where high resolution is desired. AFM has also been used in mechanical, electrical, and thermal engineering applications. This unique technique provides vital local material properties like the modulus of elasticity, hardness, surface potential, Hamaker constant, and the surface charge density from force versus displacement curve. Therefore, AFM was used to measure both the diameter and mechanical properties of the collagen nanostraws in human costal cartilage. Human costal cartilage forms a bridge between the sternum and bony ribs. The chest wall of some humans is deformed …


Coupling Of Audio Signals Into Afm Images, Matthew Manning Jun 2012

Coupling Of Audio Signals Into Afm Images, Matthew Manning

Honors Theses

It is well known that Atomic Force Microscopy imaging is capable of yielding high resolution results with of surfaces at the nanoscale. However, despite the device capabilities and vast applications, AFM microscopy is possibly the most prone to the creation of image artifacts. AFM imaging can easily, and is often, corrupted by various external forces. The most obvious and measurable form of external interference is of course the presence of ambient noise. Most AFM manufactures attempt to counter the effects of such noise on the imaging process through use of noise-proof or noise-resistant shields that cover the microscope aperture. Without …