Institut de Bioenginyeria de Catalunya (IBEC), C/Baldiri i Reixac 15-21, E-08028 Barcelona, Spain. Departament d'Electrònica, Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain.
Nanotechnology. 2013 Oct 18;24(41):415709. doi: 10.1088/0957-4484/24/41/415709. Epub 2013 Sep 24.
A theoretical analysis of amplitude modulated electrostatic force microscopy (AM-EFM) in liquid media at MHz frequencies, based on a simple tip-sample parallel plate model, is presented. The model qualitatively explains the main features of AM-EFM in liquid media and provides a simple explanation of how the measured electric forces are affected by: the frequency of the applied voltage, the tip-sample distance, the ionic concentration, the relative dielectric constant of the solution, and the relative dielectric constant and thickness of the sample. These results provide a simple framework for the design of AM-EFM measurements for localized dielectric characterization in liquid media.
本文基于简单的针尖-样品平行板模型，对 MHz 频率下液体介质中振幅调制静电力显微镜（AM-EFM）进行了理论分析。该模型定性地解释了液体介质中 AM-EFM 的主要特征，并简单说明了测量力受以下因素的影响：外加电压的频率、针尖-样品距离、离子浓度、溶液的相对介电常数以及样品的相对介电常数和厚度。这些结果为液体介质中局部介电特性的 AM-EFM 测量设计提供了一个简单的框架。
