In honour of Max Planck (1858–1947) on the occasion of his 150th birthday.
Feedback control in flashing ratchets†
Version of Record online: 17 JAN 2008
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Annalen der Physik
Volume 17, Issue 2-3, pages 115–129, February 2008
How to Cite
Craig, E.M., Kuwada, N.J., Lopez, B.J. and Linke, H. (2008), Feedback control in flashing ratchets. Ann. Phys., 17: 115–129. doi: 10.1002/andp.200710276
- Issue online: 4 FEB 2008
- Version of Record online: 17 JAN 2008
- Manuscript Received: 1 DEC 2007
- National Science Foundation. Grant Numbers: CAREER Grant No. 0239764 (HL), IGERT Grant No. DGE-0549503 (EMC)
- Engineering and Technology Industry Council of Oregon (NJK and BJL)
- Brownian ratchet;
- feedback control
A flashing ratchet uses a time-dependent, spatially periodic, asymmetric potential to rectify thermal motion of Brownian particles. Here we review approaches to improve the particle flux in this type of Brownian motor by feedback strategies that switch the potential based on the instantaneous particle distribution. We review strategies that are based on the force experienced by the particles, and introduce a new feedback strategy that is based on the expected displacement that can be achieved. Langevin dynamics simulations show that this maximum net displacement strategy performs better than force-based strategies in the limit of very small particle numbers and not too high temperatures. We also review the effects of time delay and noisy channels on feedback control, and perform a feasibility analysis of an experimental system that can realize feedback control using a computer-controlled, scanning-line optical trap and suspended microspheres.