Behaviour of an oscillating chiral squirmer in a chemical gradient

The rotational motion in addition to translation is an advantage of the chiral squirmer over a simple squirmer in such a way that the chiral one can change its orientation in any arbitrary direction. This is an important property required by the body to chemotax which is nothing but the directional movement of it in response to the chemical gradient. The chiral squirmer considered here performs an oscillatory motion in the medium which can be captured with the aid of a time-dependent surface slip velocity ^[1]. In presence of the gradient, the restricted oscillatory motion of the squirmer is altered due to the modification in the slip coefficients of the slip velocity and it starts to move towards the direction of the gradient. Here we have studied, how the net displacement of the body at the end of a complete cycle of oscillation towards the direction of the gradient depends on the strength of the gradient and the frequency of oscillation. This study can be helpful to design an artificial oscillating swimmer which is capable to chemotax.

1. R. Maity and P. S. Burada, to be submitted