Nanoelectrical characterization of individual exosomes secreted by Aβ42-ingested cells using electrostatic force microscopy

2020 ◽  
Vol 32 (2) ◽  
pp. 025705
Author(s):  
Yeseong Choi ◽  
Su-Mi Kim ◽  
Youhee Heo ◽  
Gyudo Lee ◽  
Ji Yoon Kang ◽  
...  
Keyword(s):  
Electrostatic Force ◽  
Electrostatic Force Microscopy ◽  
Force Microscopy

scholarly journals Charge Characterization of an Electrically Charged Fiber via Electrostatic Force Microscopy

2006 ◽  
Vol 1 (2) ◽  
pp. 155892500600100 ◽  
Author(s):  
Joyoun Kim ◽  
Warren J. Jasper ◽  
Juan P. Hinestroza
Keyword(s):  
Electrostatic Force ◽  
Mathematical Expression ◽  
Quantitative Agreement ◽  
Electrostatic Force Microscopy ◽  
Quantitative Interpretation ◽  
Polarization Effects ◽  
Force Microscopy ◽  
Sample Separation ◽  
Electrically Charged

The charge of a corona charged electret fiber as well as an uncharged glass fiber was characterized via Electrostatic Force Microscopy (EFM). Electrostatic force gradient images were obtained by monitoring the shifts in phase between the oscillations of the biased EFM cantilever and those of a piezoelectric driver. EFM measurements were performed using noncontact scans at a constant tip-sample separation of 75 nm with varied bias voltages applied to the cantilever. A mathematical expression, based on the Coulombic and induced polarization effects, were used to model the EFM phase shifts as a function of the applied tip bias voltages. There was quantitative agreement between the experimental data and the mathematical expression, and the quantitative interpretation for charges on the fiber was made.

scholarly journals Electrostatic force microscopy for the accurate characterization of interphases in nanocomposites

2018 ◽  
Vol 9 ◽  
pp. 2999-3012
Author(s):  
Diana El Khoury ◽  
Richard Arinero ◽  
Jean-Charles Laurentie ◽  
Mikhaël Bechelany ◽  
Michel Ramonda ◽  
...  
Keyword(s):  
Signal Analysis ◽  
Electrostatic Force ◽  
Interface State ◽  
Electrostatic Force Microscopy ◽  
Polystyrene Spheres ◽  
Promising Technique ◽  
Force Microscopy ◽  
Different Types ◽  
Experimental Protocols

The unusual properties of nanocomposites are commonly explained by the structure of their interphase. Therefore, these nanoscale interphase regions need to be precisely characterized; however, the existing high resolution experimental methods have not been reliably adapted to this purpose. Electrostatic force microscopy (EFM) represents a promising technique to fulfill this objective, although no complete and accurate interphase study has been published to date and EFM signal interpretation is not straightforward. The aim of this work was to establish accurate EFM signal analysis methods to investigate interphases in nanodielectrics using three experimental protocols. Samples with well-known, controllable properties were designed and synthesized to electrostatically model nanodielectrics with the aim of “calibrating” the EFM technique for future interphase studies. EFM was demonstrated to be able to discriminate between alumina and silicon dioxide interphase layers of 50 and 100 nm thickness deposited over polystyrene spheres and different types of matrix materials. Consistent permittivity values were also deduced by comparison of experimental data and numerical simulations, as well as the interface state of silicone dioxide layers.

Nanoscale dielectric measurements from electrostatic force microscopy

2014 ◽  
Vol 28 (24) ◽  
pp. 1430011 ◽  
Author(s):  
Bharat Kumar ◽  
Scott R. Crittenden
Keyword(s):  
Electrostatic Force ◽  
Electrical Characterization ◽  
Electrostatic Force Microscopy ◽  
Liquid Environment ◽  
Force Microscopy ◽  
Dielectric Characterization ◽  
High Lateral Resolution ◽  
Standard Tool ◽  
Made In

Electrostatic force microscopy has evolved as a standard tool for electrical characterization of surfaces with high lateral resolution. Key to its success is an accurate and informative model of the cantilever capacitance. In this brief review, we summarize the progress made in the dielectric characterization of surfaces using electrostatic force microscopy and discuss the development of various models to analytically describe the capacitive forces between the cantilever tip and sample. We include a discussion of the recent extension of these measurements to the liquid environment.

scholarly journals Characterization of Dielectric Nanocomposites with Electrostatic Force Microscopy

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
D. El Khoury ◽  
V. Fedorenko ◽  
J. Castellon ◽  
M. Bechelany ◽  
J.-C. Laurentie ◽  
...  
Keyword(s):  
Detection Method ◽  
Electrostatic Force ◽  
Effective Permittivity ◽  
Electrostatic Force Microscopy ◽  
Experimental Measurements ◽  
Electrostatic Model ◽  
Promising Technique ◽  
Force Microscopy ◽  
Interphase Interactions

Nanocomposites physical properties unexplainable by general mixture laws are usually supposed to be related to interphases, highly present at the nanoscale. The intrinsic dielectric constant of the interphase and its volume need to be considered in the prediction of the effective permittivity of nanodielectrics, for example. The electrostatic force microscope (EFM) constitutes a promising technique to probe interphases locally. This work reports theoretical finite-elements simulations and experimental measurements to interpret EFM signals in front of nanocomposites with the aim of detecting and characterizing interphases. According to simulations, we designed and synthesized appropriate samples to verify experimentally the ability of EFM to characterize a nanoshell covering nanoparticles, for different shell thicknesses. This type of samples constitutes a simplified electrostatic model of a nanodielectric. Experiments were conducted using either DC or AC-EFM polarization, with force gradient detection method. A comparison between our numerical model and experimental results was performed in order to validate our predictions for general EFM-interphase interactions.

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