Non-Stokes Drag Coefficient in Single-Particle Electrophoresis: New Insights on a Classical Problem

TL;DR

This paper presents experimental measurements of the intrinsic drag coefficient of a charged particle in electrophoresis, revealing significant deviations from classical Stokes drag predictions.

Contribution

It introduces a novel optical trapping method to measure the intrinsic drag coefficient, challenging the traditional assumptions in electrophoretic drag calculations.

Findings

Intrinsic drag coefficient differs markedly from Stokes drag.

Optical trapping enables precise measurement of single-particle drag.

Results suggest revisiting classical models of electrophoretic mobility.

Abstract

We measured the intrinsic drag coefficient of a single charged particle by optically trapping the particle and applying an alternating electric field, and found it to be markedly different from that of the Stokes drag.