Long-term stability and tree-ring oxidation of WSe2 using phase-contrast AFM

Nanoscale ◽  
2021 ◽  
Author(s):  
Lene Gammelgaard ◽  
Patrick Rebsdorf Whelan ◽  
Timothy J Booth ◽  
Peter Bøggild
Keyword(s):  
Atomic Force Microscopy ◽  
Tree Ring ◽  
Phase Contrast ◽  
Ambient Conditions ◽  
Force Microscopy ◽  
Long Term Stability ◽  
Atomic Force ◽  
Term Evolution ◽  
Ring Oxidation

In this work, we use atomic force microscopy (AFM) to investigate the long-term evolution of oxidative defects of tungsten diselenide (WSe2) in ambient conditions over a period of 75 months,...

Chromic Polydiacetylene Single Crystals: Atomic Force Microscopy Studies

1995 ◽  
Vol 413 ◽  
Author(s):  
V. Shivshankar ◽  
C. Sung ◽  
J. Kumar ◽  
S. K. Tripathy ◽  
D. J. Sandman
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Single Crystals ◽  
Ambient Conditions ◽  
Free Standing ◽  
Force Microscopy ◽  
Sensor Performance ◽  
Atomic Force ◽  
Variable Surface

ABSTRACTWe have studied the surface morphology of free standing single crystals of thermochromic polydiacetylenes (PDAs), namely, ETCD and IPUDO (respectively, the ethyl and isopropyl urethanes of 5,7-dodecadiyn-1,12-diol), by Atomic Force Microscopy (AFM) under ambient conditions. Micron scale as well as molecularly resolved images were obtained. The micron scale images indicate a variable surface, and the molecularly resolved images show a well defined 2-D lattice that is interpreted in terms of molecular models and known crystallographic data. Thereby information about surface morphology, which is crucial to potential optical device or chromic sensor performance is available. We also report the observation of a “macroscopic shattering” of the IPUDO monomer crystal during in-situ UV polymerization studies.

Phase Contrast Imaging in Atomic Force Microscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 1275-1276
Author(s):  
Sergei Magonov
Keyword(s):  
Atomic Force Microscopy ◽  
Phase Contrast ◽  
Phase Changes ◽  
Phase Imaging ◽  
Phase Detection ◽  
Contrast Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Soft Samples

Phase detection in TappingMode™ enhances capabilities of Atomic Force Microscopy (AFM) for soft samples (polymers and biological materials). Changes of amplitude and phase changes of a fast oscillating probe are caused by tip-sample force interactions. Height images reflect the amplitude changes, and in most cases they present a sample topography. Phase images show local differences between phases of free-oscillating probe and of probe interacting with a sample surface. These differences are related to the change of the resonance frequency of the probe either by attractive or repulsive tip-sample forces. Therefore phase detection helps to choose attractive or repulsive force regime for surface imaging and to minimize tip-sample force. For heterogeneous materials the phase imaging allows to distinguish individual components and to visualize their distribution due to differences in phase contrast. This is typically achieved in moderate tapping, when set-point amplitude, Asp, is about half of the amplitude of free-oscillating cantilever, Ao. In contrast, light tapping with Asp close to Ao is best suited for recording a true topography of the topmost surface layer of soft samples. Examples of phase imaging of polymers obtained with a scanning probe microscope Nanoscope® IIIa (Digital Instruments). Si probes (225 μk long, resonance frequencies 150-200 kHz) were used.

Direct Writing on Phosphate Glass Using Atomic Force Microscopy for Rapid Fabrication of Nanostructures

2016 ◽  
Author(s):  
Shama F. Barna ◽  
Kyle E. Jacobs ◽  
Glennys A. Mensing ◽  
Placid M. Ferreira
Keyword(s):  
Atomic Force Microscopy ◽  
Ion Beam ◽  
Soft Materials ◽  
Constant Current ◽  
Silver Nanostructures ◽  
Direct Writing ◽  
Ambient Conditions ◽  
Commercial Development ◽  
Force Microscopy ◽  
Atomic Force

Rapid and cost effective fabrication of nanostructures is critical for experimental exploration and translation of results for commercial development. While conventional techniques such as E-beam or Focused Ion beam lithography serve some prototyping needs for nano-scale experimentations, cost and rate considerations prohibit use for manufacturing. Specialized lithographic processes [e.g. nanosphere lithography or interference lithography] are also powerful tools in creating nanostructures but provide limited shapes, positioning and size control of nanostructures. In this work, we demonstrated a liquid-free and mask-less electrochemical writing approach using atomic force microscopy (AFM) that is capable of making arbitrary shapes of silver nanostructures in seconds on a solid state super-ionic (AgI)x (AgPO3)(1−x) glass. Under ambient conditions. silver is extracted selectively on super-ionic (AgI)x (AgPO3)(1−x) glass surface by negatively biasing an AFM probe relative to an Ag film counter electrode. Both voltage controlled and current controlled writings demonstrated localized extraction of silver. The current controlled approach is shown to be the preferred writing approach to make repeatable and uniform patterns of silver on (AgI)x AgPO3(1−x), where x represents the mole fraction of AgI in the mixture and the control parameter that tunes the conductivity of the sample. We demonstrated current controlled printing of silver on two different compositions of the material (i.e. (AgI)0.125 (AgPO3 )0.875 and (AgI)0.25(AgPO3)0.75 ). Depending on the magnitude of the constant current and tip speed, line-width of the silver pattern can be ∼150 nm. The length of these patterns are limited to the maximum distance the tip can be moved using the AFM position controls. The substrate being optically transparent allows the use of this writing technique for rapid prototyping plasmonic devices. By using the patterned substrate as a template for replica molding of soft materials such as polydimethylsiloxane (PDMS), this writing technique can also be utilized for high throughput nano-channel fabrication in biofluidics and microfluidics devices.

Effect of cantilevers' dimensions on phase contrast in multifrequency atomic force microscopy

2019 ◽  
Vol 82 (9) ◽  
pp. 1438-1447
Author(s):  
Milad Ehsanipour ◽  
Mehrnoosh Damircheli ◽  
Babak Eslami
Keyword(s):  
Atomic Force Microscopy ◽  
Phase Contrast ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Variation of Burkholderia cenocepacia cell wall morphology and mechanical properties during cystic fibrosis lung infection, assessed by atomic force microscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Amir Hassan ◽  
Miguel V. Vitorino ◽  
Tiago Robalo ◽  
Mário S. Rodrigues ◽  
Isabel Sá-Correia
Keyword(s):  
Mechanical Properties ◽  
Cystic Fibrosis ◽  
Atomic Force Microscopy ◽  
Cell Wall ◽  
Adaptive Evolution ◽  
Burkholderia Cenocepacia ◽  
Force Microscopy ◽  
Atomic Force ◽  
Morphology And Mechanical Properties

Abstract The influence that Burkholderia cenocepacia adaptive evolution during long-term infection in cystic fibrosis (CF) patients has on cell wall morphology and mechanical properties is poorly understood despite their crucial role in cell physiology, persistent infection and pathogenesis. Cell wall morphology and physical properties of three B. cenocepacia isolates collected from a CF patient over a period of 3.5 years were compared using atomic force microscopy (AFM). These serial clonal variants include the first isolate retrieved from the patient and two late isolates obtained after three years of infection and before the patient’s death with cepacia syndrome. A consistent and progressive decrease of cell height and a cell shape evolution during infection, from the typical rods to morphology closer to cocci, were observed. The images of cells grown in biofilms showed an identical cell size reduction pattern. Additionally, the apparent elasticity modulus significantly decreases from the early isolate to the last clonal variant retrieved from the patient but the intermediary highly antibiotic resistant clonal isolate showed the highest elasticity values. Concerning the adhesion of bacteria surface to the AFM tip, the first isolate was found to adhere better than the late isolates whose lipopolysaccharide (LPS) structure loss the O-antigen (OAg) during CF infection. The OAg is known to influence Gram-negative bacteria adhesion and be an important factor in B. cenocepacia adaptation to chronic infection. Results reinforce the concept of the occurrence of phenotypic heterogeneity and adaptive evolution, also at the level of cell size, form, envelope topography and physical properties during long-term infection.

In-plane contributions to phase contrast in intermittent contact atomic force microscopy

2003 ◽  
Vol 97 (1-4) ◽  
pp. 145-150 ◽  
Author(s):  
Matthew S. Marcus ◽  
M.A. Eriksson ◽  
Darryl Y. Sasaki ◽  
Robert W. Carpick
Keyword(s):  
Atomic Force Microscopy ◽  
Phase Contrast ◽  
Force Microscopy ◽  
Atomic Force ◽  
Intermittent Contact

AFM Study of Untreated and Treated Fibers of Mongolian Goat Cashmere

2009 ◽  
Vol 610-613 ◽  
pp. 175-178 ◽  
Author(s):  
Namsrai Javkhlantugs ◽  
Enkhbaatar Ankhbayar ◽  
Khishigjargal Tegshjargal ◽  
Damdin Enkhjargal ◽  
Chimed Ganzorig
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Fine Structure ◽  
Ambient Conditions ◽  
Bleaching Process ◽  
Surface Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
The Difference

The morphological surface change of untreated and treated fibers of the Mongolian goat cashmere was investigated by atomic force microscopy (AFM) at ambient conditions. The cuticle scale heights of the Mongolian goat cashmere fibers were measured by the AFM for the fibers before and after treatment. The experimental results showed that the difference between the fine structure of the cuticle and surface roughness of untreated and treated fibers. We found that the surface morphological change of the cashmere fibers was strongly degraded after the bleaching process.

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