Low-Reynolds-number predator

Abstract

To generalize simple bead-linker model of swimmers to higher dimensions and to demonstrate the chemotaxis ability of such swimmers, here we introduce a low-Reynolds predator, using a two-dimensional triangular bead-spring model. Two-state linkers as mechanochemical enzymes expand as a result of interaction with particular activator substances in the environment, causing the whole body to translate and rotate. The concentration of the chemical stimulator controls expansion versus the contraction rate of each arm and so affects the ability of the body for diffusive movements; also the variation of activator substance's concentration in the environment breaks the symmetry of linkers' preferred state, resulting in the drift of the random walker along the gradient of the density of activators. External food or danger sources may attract or repel the body by producing or consuming the chemical activators of the organism's enzymes, inducing chemotaxis behavior. Generalization of the model to three dimensions is straightforward.

Analytical Approach for Calculating the Chemotaxis Sensitivity Function

“…For the one dimensional geometry (where 0 ≤ x ≤ L), this equation with the boundary condition j b z=0 = 0 (11) (which means zero bacteria flux at the left boundary) produces the next formula determining the relation between the bacteria concentration b(x) and the attractant concentration a(x):…”

“…This phenomenon is known as the chemotaxis [1][2][3][4][5][6]. Although there many interesting and significant results have been received in this area (for example, see [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]), we are going to pay some attention to the process of the bacteria redistribution under the presence of attractant.…”

Active Brownian particles and run-and-tumble particles separate inside a maze

“…Active particle systems have attracted a lot of attention during the last decades [1][2][3] . Much effort has been devoted to study and mimic the motion of motile bacteria, molecular motors, and other natural low-Reynolds-number swimmers [4][5][6][7][8][9][10][11][12][13][14][15] . With the significant advance of micro-and nanotechnology, different powerful artificial micro-and nanoswimmers have been fabricated.…”

Optimal motion control of three-sphere based low-Reynolds number swimming microrobot

“…(This behavior is known as the scallop theorem [21].) Based on this theorem, several microswimmers have been proposed during recent years [22][23][24][25][26]. To name but a few, Rizvi et al [24] introduced a triangular three-bead microswimmer where three identical springs connect the beads.…”