Related Experiment Video
Updated: May 10, 2026

Asymmetric Walkway: A Novel Behavioral Assay for Studying Asymmetric Locomotion
Published on: January 15, 2016
Asymmetric drag in oscillatory motion: ratchet effect without an asymmetric potential
Vladimir M Fomin1, Elliot J Smith, Dmitriy D Karnaushenko
1Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany. v.fomin@ifw-dresden.de
Abstract:
Asymmetry of magnetic objects in a fluid under an oscillating magnetic field leads to a wealth of nonequilibrium dynamics phenomena including a novel ratchet effect without an asymmetric substrate. These nonlinear dynamics are explained in the framework of the Stokes' model by a drag coefficient, which depends on the direction of motion. This approach is general and is independent of the physical mechanism responsible for this directional dependence of the drag coefficient as well as the size of the object. The theoretical model is experimentally verified for two systems, a nonrigid magnetic microcoil and a chiral magnetic macroobject immersed in a bounded fluid.
Related Concept Videos
Forced Oscillations
Damped Oscillations
Although friction and other non-conservative...
Torsional Pendulum
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played by the...
Types of Damping
Rolling Without Slipping
Oscillations about an Equilibrium Position

