title: 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.
authors.affiliation: Department of Management and Economics, Sharif University of Technology.
authors.forename: Mehran
authors.initials: M
authors.lastname: Ebrahimian
authors.affiliation: Department of Electrical Engineering, Sharif University of Technology.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Yekehzare
authors.affiliation: Department of Physics and Center of Excellence in Complex systems and Condensed Matter, Sharif University of Technology, Tehran, 1458889694, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ejtehadi