title: Colloidal transport by active filaments.
abstract: Enhanced colloidal transport beyond the limit imposed by diffusion is usually achieved through external fields. Here, we demonstrate the ballistic transport of a colloidal sphere using internal sources of energy provided by an attached active filament. The latter is modeled as a chain of chemo-mechanically active beads connected by potentials that enforce semi-flexibility and self-avoidance. The fluid flow produced by the active beads and the forces they mediate are explicitly taken into account in the overdamped equations of motion describing the colloid-filament assembly. The speed and efficiency of transport depend on the dynamical conformational states of the filament. We characterize these states using filament writhe as an order parameter and identify ones yielding maxima in speed and efficiency of transport. The transport mechanism reported here has a remarkable resemblance to the flagellar propulsion of microorganisms which suggests its utility in biomimetic systems.
authors.affiliation: Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Raj Kumar
authors.initials: RK
authors.lastname: Manna
authors.affiliation: Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: P B Sunil
authors.initials: PB
authors.lastname: Kumar
authors.affiliation: The Institute of Mathematical Sciences-HBNI, CIT Campus, Chennai 600113, India.
authors.forename: R
authors.initials: R
authors.lastname: Adhikari
mesh_terms: D001693:Biological Transport, Active; D003102:Colloids / Q000737:chemistry*; D008870:Microtubules / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D020409:Molecular Motor Proteins / Q000737:chemistry; D009038:Motion
chemical_list: D003102:Colloids; D020409:Molecular Motor Proteins