Ratchet Effect and Particle Diffusion in an Underdamped Inhomogeneous Periodic Potential System

2020 ◽  
Vol 7 (1) ◽  
pp. 01-11
Author(s):  
Shantu Saikia ◽  
◽  
Francis Iawphniaw
Keyword(s):  
Periodic Potential ◽  
Thermal Fluctuations ◽  
Particle Dynamics ◽  
Particle Diffusion ◽  
Biological Processes ◽  
Ratchet Effect ◽  
External Bias ◽  
Potential System ◽  
Constructive Work ◽  
Random Fluctuations

Thermal fluctuations or noise assisted particle dynamics in a driven underdamped inhomogeneous periodic potential system is studied. This forms an archetypal model to study different Physical and Biological processes in the microscopic domain. The particles are shown to exhibit directed transport aided by these fluctuations without the application of any external bias. This phenomenon, also known as ratchet effect, is a counterintuitive phenomenon in which systems in the microscopic domain harnesses the energy of the random fluctuations to do constructive work. Also in the presence of random thermal fluctuations or noise, the particles undergo diffusion, the amount of which can be controlled by controlling the different parameters of the system. This can have important technological applications.

scholarly journals ENSLAVING RANDOM FLUCTUATIONS IN NONEQUILIBRIUM SYSTEMS

1996 ◽  
Vol 10 (28) ◽  
pp. 3857-3873 ◽  
Author(s):  
MANGAL C. MAHATO ◽  
T.P. PAREEK ◽  
A.M. JAYANNAVAR
Keyword(s):  
Periodic Potential ◽  
Brownian Particle ◽  
Physical Models ◽  
Temperature Inhomogeneity ◽  
Stable States ◽  
Inhomogeneous Systems ◽  
Potential System ◽  
Macroscopic Motion ◽  
Random Fluctuations ◽  
Unidirectional Motion

Several physical models have recently been proposed to obtain unidirectional motion of an overdamped Brownian particle in a periodic system. The asymmetric ratchetlike form of the periodic potential and the presence of correlated nonequilibrium fluctuating forces are considered essential to obtain such a macroscopic motion in homogeneous systems. In the present work, instead, inhomogeneous systems are considered, wherein the friction coefficient and/or temperature could vary in space. We show that unidirectional motion can be obtained even in a symmetric nonratchetlike periodic potential system in the presence of white noise fluctuations. We consider four different cases of system inhomogeneity. We argue that all these different models work under the same basic principle of alteration of relative stability of otherwise locally stable states in the presence of temperature inhomogeneity.

scholarly journals Particle dynamics in a symmetrically driven underdamped inhomogeneous periodic potential system

2017 ◽  
Author(s):  
D. Kharkongor ◽  
S. Saikia ◽  
A. M. Jayannavar ◽  
Mangal C. Mahato ◽  
W. L. Reenbohn
Keyword(s):  
Periodic Potential ◽  
Particle Dynamics ◽  
Potential System

Micromachined Linear Brownian Motor: A Nanosystem Exploting Brownian Motion of Nanobeads for Uni-directional Transport

2008 ◽  
Vol 1096 ◽  
Author(s):  
Ersin Altintas ◽  
Edin Sarajlic ◽  
Karl F. Bohringer ◽  
Hiroyuki Fujita
Keyword(s):  
Brownian Motion ◽  
Three Dimensional ◽  
Thermal Fluctuations ◽  
Random Motion ◽  
Microfluidic Channels ◽  
Switching Sequence ◽  
Brownian Motor ◽  
Speed Performance ◽  
Random Fluctuations ◽  
Directional Transport

AbstractNanosystems operating in liquid media may suffer from random thermal fluctuations. Some natural nanosystems, e.g. biomolecular motors, which survive in an environment where the energy required for bio-processes is comparable to thermal energy, exploit these random fluctuations to generate a controllable unidirectional movement. Inspired by the nature, a transportation system of nanobeads achieved by exploiting Brownian motion were proposed and realized. This decreases energy consumption and saves the energy compared to ordinal pure electric or magnetic drive. In this paper we present a linear Brownian motor with a 3-phase electrostatic rectification aimed for unidirectional transport of nanobeads in microfluidic channels. The transport of the beads is performed in 1 μm deep, 2 μm wide PDMS microchannels, which constrain three-dimensional random motion of nanobeads into 1D fluctuation, so-called tamed Brownian motion. We have experimentally traced the rectified motion of nanobeads and observed the shift in the beam distribution as a function of applied voltage. The detailed computational analysis on the importance of switching sequence on the speed performance of motor is performed and compared with the experimental results showing a good agreement.

Simulation of Dripping Using Dissipative Particle Dynamics

2010 ◽  
Author(s):  
Sorush Khajepor ◽  
Meysam Joulaian ◽  
Ahmadreza Pishevar ◽  
Yaser Afshar
Keyword(s):  
Dissipative Particle Dynamics ◽  
Thermal Fluctuations ◽  
Particle Dynamics ◽  
Fluid Density ◽  
Mesoscopic Simulation ◽  
Wall Boundary Condition ◽  
Wide Range ◽  
Breakup Time ◽  
Dpd Simulation ◽  
Good Agreement

Dissipative Particle Dynamics (DPD) is a mesoscopic simulation approach used in wide range of applications and length scales. In this paper, a DPD simulation is carried out to study dripping flow from a nozzle. The results of this study are used to answer this question that whether DPD is capable of simulating the free surface fluid on all different scales. A novel wall boundary condition is developed for the nozzle surface that controls its penetrability, near wall fluid density oscillations and the fluid slip close to the wall. We also utilize a new method to capture the real-time instantaneous geometry of the drop. The obtained results are in good agreement with the macroscopic experiment except near the breakup time, when the fluid thread that connects the primitive drop to the nozzle, becomes tenuous. At this point, the DPD simulation can be justified by thermal length of DPD fluid and the finest accuracy of the simulation that is the radius of a particle. We finally conclude that in spite of the fact that DPD can be used potentially for simulating flow on different scales, it is restricted to the nanoscale problems, due to the surface thermal fluctuations.

scholarly journals EFFICIENCY AND CURRENT REVERSALS IN SPATIALLY INHOMOGENEOUS RATCHETS

2000 ◽  
Vol 14 (15) ◽  
pp. 1585-1591 ◽  
Author(s):  
DEBASIS DAN ◽  
A. M. JAYANNAVAR ◽  
MANGAL C. MAHATO
Keyword(s):  
Friction Coefficient ◽  
Periodic Potential ◽  
Inhomogeneous System ◽  
Noise Strength ◽  
Spatially Inhomogeneous ◽  
Potential System ◽  
Maximum Current ◽  
Spatially Varying

Efficiency of generation of net unidirectional current in an adiabatically driven symmetric periodic potential system is studied. The efficiency shows a maximum, in the case of an inhomogeneous system with spatially varying periodic friction coefficient, as a function of temperature. The ratchet is not most efficient when it gives maximum current. The direction of current may also be reversed as a function of noise strength when, instead, an asymmetric periodic potential is considered.

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