Project Details
Projekt
Cooperative properties of thermophoretic microswimmers
Applicant
Dr. Marisol Ripoll
Subject Area
Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
Term
from 2014 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 255110239
Due to their similitude with biological systems and their potential practical applications, for example in lab-on-a-chip devices, synthetic microswimmers are receiving rapidly increasing attention. Self-phoretic effects have shown to be an effective and promising strategy to design such artificial microswimmers. Thermophoretic swimmers account for inhomogeneous surface heating, such that they propel due to the presence of self-generated local temperature gradients in the presence of external heating, for example by laser illumination or magnetic stimulation. The microswimmer simulation models that we have already developed and that are currently functional are microdimers, Janus colloids, and microgears. The details of the solvent interactions with the microswimmer surface determines the thermophilic or thermophobic character of the phoretic forces, and this character will be crucial to determine the microswimmer behavior, together with the particle size and shape. In this way, different microdimers have shown to hydrodynamically behave like pushers, pullers, or neutral particles; this is to generate attractive, repulsive, or neutral interparticle interactions driven by the surrounding fluid. These hydrodynamic interactions will coexist with the phoretic interactions which can have the same or different directions. The interplay of these different mechanisms, and the variety of resulting behaviors is still largely unexplored. The main purpose of this project is to investigate, by means of mesoscopic simulations the properties of solutions with multiple swimmers and of mixtures of swimmers with passive particles. This research will be performed mainly with Janus colloids, dimers, trimers, and eventually other swimmers shapes. Of particular interest are the trimers, which offer a high possible degree of asymmetry, considering the bead sizes and composition of the three beads. These might result in swimmers with a large persistent motion, different asymmetric interactions, and also moving with elliptical orbits, and with large range of chiral interactions. The investigation of the collective behavior of these swimmers will display important phenomena like clustering, swarming, and various types of synchronized motion. Some of the self-assembled structures are expected to be long-lived, under circumstances still to be identified. Examples of phenomena with important potential applications are the directed motion of phoretic swimmers, and the assembly of swimmers around a passive phoretic particle, which would enable to transport and deliver cargo to designated areas.
DFG Programme
Priority Programmes
