Influence of swimming strategy on microorganism separation by asymmetric obstacles

I. BERDAKIN; Y. JEYARAM; V. V. MOSHCHALKOV; L. VENKEN; S. DIERCKX; J. VANDERLEYDEN; A. V. SILHANEK; C. A. CONDAT; V.I. MARCONI

PHYSICAL REVIEW E

AMER PHYSICAL SOC

Lugar: New York; Año: 2013 vol. 87 p. 1 - 9

1539-3755

It has been shown that a nanoliter chamber separated by a wall of asymmetric obstacles can lead toan inhomogeneous distribution of self-propelled microorganisms. Although it is well established that thisrectification effect arises from the interaction between the swimmers and the noncentrosymmetric pillars, herewe demonstrate numerically that its efficiency is strongly dependent on the detailed dynamics of the individualmicroorganism. In particular, for the case of run-and-tumble dynamics, the distribution of run lengths, therotational diffusion, and the partial preservation of run orientation memory through a tumble are importantfactors when computing the rectification efficiency. In addition, we optimize the geometrical dimensions of theasymmetric pillars in order to maximize the swimmer concentration and we illustrate how it can be used forsorting by swimming strategy in a long array of parallel obstacles.