Gaining insight into the physics of dynamic atomic force microscopy in complex environments using the VEDA simulator

2012 ◽  
Vol 83 (1) ◽  
pp. 013702 ◽  
Author(s):  
Daniel Kiracofe ◽  
John Melcher ◽  
Arvind Raman
2019 ◽  
Vol 667 ◽  
pp. 14-21 ◽  
Author(s):  
Justin S. Plaut ◽  
Agnieszka Strzelecka-Kiliszek ◽  
Lukasz Bozycki ◽  
Slawomir Pikula ◽  
René Buchet ◽  
...  

2005 ◽  
Vol 904 ◽  
Author(s):  
Tanguy Rouxel ◽  
Satoshi Yoshida ◽  
Haixia Shang ◽  
Jean-Christophe Sangleboeuf

AbstractThe response of a material to a sharp contact loading, as in the case of Vickers indentation for instance, provides a unique insight into the material constitutive law, including elastic and irreversible deformation parameters as well. However, under such peculiar thermodynamical and mechanical conditions (the mean contact pressure on the contact area reaches values typically higher than 1 GPa, corresponding to the hardness of the material) the deformation processes are complex and the matter located just beneath and around the contact area may experience some structural changes and behave in a way different to the expected - or known - macroscopic behaviour. It is showed in this study by means of detailed topological investigations of the residual indentations by Atomic Force Microscopy (AFM) that the elastic recovery typically represents 50 to 70 % of the indentation volume at maximum load and that the densification contribution may reach 90 % of the residual deformation volume. Besides, most glasses exhibit indentation-creep phenomena, which become significant over time scale of few minutes because of a pronounced shear-thinning behavior..


Author(s):  
Adam U. Kareem ◽  
Santiago D. Solares

We present numerical simulations of a recently developed atomic force microscopy (AFM) technique known as the Band Excitation Method, developed by Jesse et al. [2007 Nanotechnology 18 435503]. With this technique an AFM microcantilever is simultaneously excited and the response measured over a continuum band of frequencies. The purpose of this work is to introduce an analytical model providing insight into the dynamics of the Band Excitation Method, which can help in the translation of the acquired signals into sample properties. As an initial step we examine the cantilever response to two distinct excitation signals, the chirp and sinc functions, both of which have uniform frequency content, differing only in the phase content.


2021 ◽  
Author(s):  
Serena Ducoli ◽  
Stefania Federici ◽  
Roland Nicsanu ◽  
Andrea Zendrini ◽  
Claudio Marchesi ◽  
...  

Given the complexity of separating nanoplastics from environmental samples, studies have usually been conducted using synthetic polystyrene nanobeads. By mechanical fragmentation in cryogenic conditions of daily-life plastic items, we produced “true-to-life” nanoplastics (T2LNPs), that promises to give a true insight into the interaction with biological systems. T2LNPs have been fully characterized by Fourier transform Infrared spectroscopy and by Atomic Force Microscopy. They result in populations of spheroidal nanoparticles with a broad multimodal size distribution. The mandatory need for a representative sample to evaluate the potential effects of nanoparticles on human health and the environment is demonstrated by the different protein corona identified on T2LNPs and synthetic polystyrene nanobeads upon incubation with human plasma.


2021 ◽  
Author(s):  
Serena Ducoli ◽  
Stefania Federici ◽  
Roland Nicsanu ◽  
Andrea Zendrini ◽  
Claudio Marchesi ◽  
...  

Given the complexity of separating nanoplastics from environmental samples, studies have usually been conducted using synthetic polystyrene nanobeads. By mechanical fragmentation in cryogenic conditions of daily-life plastic items, we produced “true-to-life” nanoplastics (T2LNPs), that promises to give a true insight into the interaction with biological systems. T2LNPs have been fully characterized by Fourier transform Infrared spectroscopy and by Atomic Force Microscopy. They result in populations of spheroidal nanoparticles with a broad multimodal size distribution. The mandatory need for a representative sample to evaluate the potential effects of nanoparticles on human health and the environment is demonstrated by the different protein corona identified on T2LNPs and synthetic polystyrene nanobeads upon incubation with human plasma.


2015 ◽  
Vol 26 (18) ◽  
pp. 3190-3204 ◽  
Author(s):  
Tetyana Gudzenko ◽  
Clemens M. Franz

Fibronectin (FN) is an extracellular matrix protein that can be assembled by cells into large fibrillar networks, but the dynamics of FN remodeling and the transition through intermediate fibrillar stages are incompletely understood. Here we used a combination of fluorescence microscopy and time-lapse atomic force microscopy (AFM) to visualize initial stages of FN fibrillogenesis in living fibroblasts at high resolution. Initial FN nanofibrils form within <5 min of cell–matrix contact and subsequently extend at a rate of 0.25 μm/min at sites of cell membrane retraction. FN nanofibrils display a complex linear array of globular features spaced at varying distances, indicating the coexistence of different conformational states within the fibril. In some cases, initial fibrils extended in discrete increments of ∼800 nm during a series of cyclical membrane retractions, indicating a stepwise fibrillar extension mechanism. In presence of Mn2+, a known activator of integrin adhesion to FN, fibrillogenesis was accelerated almost threefold to 0.68 μm/min and fibrillar dimensions were increased, underlining the importance of integrin activation for early FN fibrillogenesis. FN fibrillogenesis visualized by time-lapse AFM thus provides new structural and mechanistic insight into initial steps of cell-driven FN fibrillogenesis.


The Analyst ◽  
2019 ◽  
Vol 144 (16) ◽  
pp. 4985-4994
Author(s):  
Alison O. Nwokeoji ◽  
Sandip Kumar ◽  
Peter M. Kilby ◽  
David E. Portwood ◽  
Jamie K. Hobbs ◽  
...  

Atomic force microscopy (AFM) in conjunction with ion-pair reverse-phase high performance liquid chromatography (IP-RP-HPLC) provides novel insight into dsRNA for RNAi applications.


Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2509-2516 ◽  
Author(s):  
Peter Jacobse ◽  
Marc-Etienne Moret ◽  
Robertus Klein Gebbink ◽  
Ingmar Swart

The field of on-surface synthesis has seen a tremendous development in the past decade as an exciting new methodology towards atomically well-defined nanostructures. A strong driving force in this respect is its inherent compatibility with scanning probe techniques, which allows one to ‘view’ the reactants and products at the single-molecule level. In this article, we review the ability of noncontact atomic force microscopy to study on-surface chemical reactions with atomic precision. We highlight recent advances in using noncontact atomic force microscopy to obtain mechanistic insight into reactions and focus on the recently elaborated mechanisms in the formation of different types of graphene nanoribbons.


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