Direct Measurement of Periodic Electric Forces in Liquids

TL;DR

This paper presents a novel method for directly measuring and mapping periodic electrostatic forces on an AFM tip in liquids, providing detailed insights into electrostatic interactions relevant for nanomanipulation.

Contribution

It introduces a microelectrochemical measurement technique that captures real-space electrostatic force components in liquids, advancing understanding of electrostatic phenomena in nanoscale systems.

Findings

Real-space mapping of electrostatic forces achieved

Force measurements as a function of lift height and bias parameters

Method enables probing of electrostatic and convective forces in liquids

Abstract

The electric forces acting on an atomic force microscope tip in solution have been measured using a microelectrochemical cell formed by two periodically biased electrodes. The forces were measured as a function of lift height and bias amplitude and frequency, providing insight into electrostatic interactions in liquids. Real-space mapping of the vertical and lateral components of electrostatic forces acting on the tip from the deflection and torsion of the cantilever is demonstrated. This method enables direct probing of electrostatic and convective forces involved in electrophoretic and dielectroforetic self-assembly and electrical tweezer operation in liquid environments.