Stochastic thermodynamics with a Brownian particle in an optical trap (Presentation Recording)

2015 ◽  
Author(s):  
Ignacio A. Martinez ◽  
Édgar Roldán ◽  
Luis Dinis ◽  
Pau Mestres ◽  
Juan M. R. Parrondo ◽  
...  
2013 ◽  
Vol 81 (3) ◽  
pp. 224-230 ◽  
Author(s):  
Giorgio Volpe ◽  
Giovanni Volpe

Entropy ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 8
Author(s):  
Luis Dinis ◽  
Juan Manuel Rodríguez Parrondo

Measurement and feedback allows for an external agent to extract work from a system in contact with a single thermal bath. The maximum amount of work that can be extracted in a single measurement and the corresponding feedback loop is given by the information that is acquired via the measurement, a result that manifests the close relation between information theory and stochastic thermodynamics. In this paper, we show how to reversibly confine a Brownian particle in an optical tweezer potential and then extract the corresponding increase of the free energy as work. By repeatedly tracking the position of the particle and modifying the potential accordingly, we can extract work optimally, even with a high degree of inaccuracy in the measurements.


2021 ◽  
Vol 2021 (11) ◽  
pp. 113205
Author(s):  
Matthieu Mangeat ◽  
Thomas Guérin ◽  
David S Dean

Abstract Optically trapped particles are often subject to a non-conservative scattering force arising from radiation pressure. In this paper, we present an exact solution for the steady state statistics of an overdamped Brownian particle subjected to a commonly used force field model for an optical trap. The model is the simplest of its kind that takes into account non-conservative forces. In particular, we present the exact results for certain marginals of the full three-dimensional steady state probability distribution, in addition to results for the toroidal probability currents that are present in the steady state, as well as for the circulation of these currents. Our analytical results are confirmed by numerical solution of the steady state Fokker–Planck equation.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 515
Author(s):  
Andrea Cugno ◽  
Alex Marki ◽  
Klaus Ley

Leukocytes, including neutrophils, which are propelled by blood flow, can roll on inflamed endothelium using transient bonds between selectins and their ligands, and integrins and their ligands. When such receptor–ligand bonds last long enough, the leukocyte microvilli become extended and eventually form thin, 20 m long tethers. Tether formation can be observed in blood vessels in vivo and in microfluidic flow chambers. Tethers can also be extracted using micropipette aspiration, biomembrane force probe, optical trap, or atomic force microscopy approaches. Here, we review the biomechanical properties of leukocyte tethers as gleaned from such measurements and discuss the advantages and disadvantages of each approach. We also review and discuss viscoelastic models that describe the dependence of tether formation on time, force, rate of loading, and cell activation. We close by emphasizing the need to combine experimental observations with quantitative models and computer simulations to understand how tether formation is affected by membrane tension, membrane reservoir, and interactions of the membrane with the cytoskeleton.


Author(s):  
J. G. H. Franssen ◽  
T. C. H. de Raadt ◽  
M. A. W. van Ninhuijs ◽  
O. J. Luiten

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