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Enhancement of mobility in an interacting colloidal system under feedback control
Robert Gernert1, Sabine H L Klapp1
1Institut für Theoretische Physik, Sekr. EW 7-1, Technische Universität Berlin, Hardenbergstrasse 36, D-10623 Berlin, Germany.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 19, 2015
Summary
Feedback control significantly enhances colloidal particle transport through a washboard potential. This method boosts particle mobility by orders of magnitude, even with slight delays.
Area of Science:
- Soft matter physics
- Statistical mechanics
- Non-equilibrium systems
Background:
- Colloidal suspensions exhibit complex transport behaviors.
- Feedback control offers a method to manipulate these properties.
- Driven colloidal systems require precise control for targeted applications.
Purpose of the Study:
- To propose and analyze a feedback control scheme for enhancing collective transport.
- To investigate the effects of feedback on colloidal particles in a tilted washboard potential.
- To determine the impact of interaction types and trap parameters on transport enhancement.
Main Methods:
- Theoretical analysis using the Smoluchowski equation.
- Dynamical density functional theory for hard-core and ultrasoft interactions.
- Modeling control via a moving harmonic confining potential (optical trap).
Main Results:
- Feedback control enhances particle mobility by several orders of magnitude.
- Maximum enhancement observed for intermediate trap stiffness and large particle numbers.
- Feedback can induce oscillations in mean velocity and is robust to time delays.
Conclusions:
- Feedback control is a powerful tool for manipulating colloidal transport.
- The proposed scheme offers significant mobility enhancement for driven colloidal suspensions.
- The method's robustness suggests practical applicability in controlling colloidal systems.
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