Electrostatic backscattering by insulating obstacles

Electrostatic backscattering by insulating obstacles

We introduce and analyze backscatter data for a three dimensional obstacle problem in electrostatics. In particular, we investigate the asymptotic behavior of these data as, (i), the measurement point goes to infinity, and (ii), the obstacles shrink to individual points. We also provide numerical simulations of these data.

Nanoscale electric polarizability of ultrathin biolayers on insulating substrates by electrostatic force microscopy.

We measured and quantified the local electric polarization properties of ultrathin (∼5 nm) biolayers on mm-thick mica substrates. We achieved it by scanning a sharp conductive tip (<10 nm radius) of an electrostatic force microscope over the biolayers and quantifying sub-picoNewton electric polarization forces with a sharp-tip model implemented using finite-element numerical calculations. We ob...

Dielectric properties of thin insulating layers measured by Electrostatic Force Microscopy

In order to measure the dielectric permittivity of thin insulting layers, we developed a method based on electrostatic force microscopy (EFM) experiments coupled with numerical simulations. This method allows to characterize the dielectric properties of materials without any restrictions of film thickness, tip radius and tip-sample distance. The EFM experiments consist in the detection of the e...

Comment on "electrostatic force microscopy on oriented graphite surfaces: coexistence of insulating and conducting behaviors".

In a recent Letter [1], Lu et al. claimed to have identified insulating and conductive regions on a highly oriented pyrolytic graphite (HOPG) surface by differences in the surface potential. Because of the reasons given below, the results presented do not give sufficient evidence to support the claims made. (1) The minimum of the force gradient signal corresponds to the contact potential differ...

Electric Field Dependence of the Time to Electrostatic Breakdown in Insulating Polymers