Chemistry in Motion: Tiny Synthetic Motors

Abstract

In this Account, we describe how synthetic motors that operate by self-diffusiophoresis make use of a self-generated concentration gradient to drive motor motion. A description of propulsion by self-diffusiophoresis is presented for Janus particle motors comprising catalytic and noncatalytic faces. The properties of the dynamics of chemically powered motors are illustrated by presenting the results of particle-based simulations of sphere-dimer motors constructed from linked catalytic and noncatalytic spheres. The geometries of both Janus and sphere-dimer motors with asymmetric catalytic activity support the formation of concentration gradients around the motors. Because directed motion can occur only when the system is not in equilibrium, the nature of the environment and the role it plays in motor dynamics are described. Rotational Brownian motion also acts to limit directed motion, and it has especially strong effects for very small motors. We address the following question: how small can motors be and still exhibit effects due to propulsion, even if only to enhance diffusion? Synthetic motors have the potential to transform the manner in which chemical dynamical processes are carried out for a wide range of applications.

12 pages, 8 figures

References in corpus (5)

• Self-motile colloidal particles: from directed propulsion to random walk
• Propulsion of a molecular machine by asymmetric distribution of reaction--products
• Designing phoretic micro- and nano-swimmers
• Phoretic self-propulsion at finite Péclet numbers
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Cited by in corpus (10)

• Self-assembly of Active Colloidal Molecules with Dynamic Function
• Chemotactic and hydrodynamic effects on collective dynamics of self-diffusiophoretic Janus motors
• Absolute diffusion measurements of active enzyme solutions by NMR
• Swimming with a cage: Low-Reynolds-number locomotion inside a droplet
• Mechanochemical fluctuation theorem and thermodynamics of self-phoretic motors
• Wall curvature driven dynamics of a microswimmer
• Designing, Synthesizing and Modeling Active Fluids
• Microscopic and continuum descriptions of Janus motor fluid flow fields
• Efficiency of isothermal active matter engines: Strong driving beats weak driving
• Self-organization of active colloids mediated by chemical interactions