Vacuum plasma sprayed hydroxyapatite coatings on titanium alloy substrates: Surface characterization and observation of dissolution processes using atomic force microscopy

Author(s):  
P. A. Campbell
2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.


Author(s):  
José M. Barandiarán ◽  
Iñaki Orue ◽  
M.L. Fdez-Gubieda ◽  
A. García Prieto

2001 ◽  
Vol 16 (3) ◽  
pp. 844-855 ◽  
Author(s):  
M. S. Bobji ◽  
Bharat Bhushan

Atomic force microscopy (AFM) has been used to study the cracks developed on thin-film coatings on a polymer substrate subjected to external tension. To conduct in situ tensile tests in AFM, a special stage has been built. A new technique to image the same control area at different strains was developed and used to study the propagation of a crack with increasing strain in magnetic tapes. Metal particulate tapes developed numerous cracks of shorter length, perpendicular to the loading direction. In contrast, metal-evaporated tapes developed cracks that extend edge to edge. The variation of the crack width and the spacing with strain were measured and explained with the help of models based on elasticity.


Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-25 ◽  
Author(s):  
Andreas Stylianou ◽  
Stylianos-Vasileios Kontomaris ◽  
Colin Grant ◽  
Eleni Alexandratou

Atomic force microscopy (AFM) is an easy-to-use, powerful, high-resolution microscope that allows the user to image any surface and under any aqueous condition. AFM has been used in the investigation of the structural and mechanical properties of a wide range of biological matters including biomolecules, biomaterials, cells, and tissues. It provides the capacity to acquire high-resolution images of biosamples at the nanoscale and allows at readily carrying out mechanical characterization. The capacity of AFM to image and interact with surfaces, under physiologically relevant conditions, is of great importance for realistic and accurate medical and pharmaceutical applications. The aim of this paper is to review recent trends of the use of AFM on biological materials related to health and sickness. First, we present AFM components and its different imaging modes and we continue with combined imaging and coupled AFM systems. Then, we discuss the use of AFM to nanocharacterize collagen, the major fibrous protein of the human body, which has been correlated with many pathological conditions. In the next section, AFM nanolevel surface characterization as a tool to detect possible pathological conditions such as osteoarthritis and cancer is presented. Finally, we demonstrate the use of AFM for studying other pathological conditions, such as Alzheimer’s disease and human immunodeficiency virus (HIV), through the investigation of amyloid fibrils and viruses, respectively. Consequently, AFM stands out as the ideal research instrument for exploring the detection of pathological conditions even at very early stages, making it very attractive in the area of bio- and nanomedicine.


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