Another main thrust of research in the group is concerned with microscopic models of active systems such as Janus particles that behave as synthetic motors that catalyze the conversion of fuel and thereby propel themselves in solution by self- diffusiophoresis. In this mechanism the concentration gradient generated by asymmetric catalytic activity leads to a force on the motor that induces fluid flows in the surrounding medium. Such active media, whose constituents are able to move autonomously, display novel features that differ from those of equilibrium systems. In collaboration with Ray Kapral and his group members, our group is working on methods of simulating and characterizing cooperative motion in active systems such as flocking using microscopic models. Theoretical work is focussed on deriving evolution equations for the coarse grained dynamics of the system from first principles, and using generalizations of local equilibrium ensembles to describe correlations and fluctuations in steady state and non-equilibrium systems.
- Movie of forward-moving self-diffusiophoretic Janus particle where fuel is more repulsive than product. (58MB)
- Movie of backward-moving self-diffusiophoretic Janus particle where product is more repulsive than fuel. (43MB)
- Movie of cooperative motion in a collection of forward-moving Janus particles. (102 MB)
- M.-J. Huang, J. Schofield and R. Kapral, "Transport in active systems crowded by obstacles" ,
J. Phys. A: Math. Theor. 50 074001 (2017) (9 pages)
- S.Y. Reigh, M.-J. Huang, J. Schofield and R. Kapral, "Microscopic and continuum descriptions of Janus motor fluid flow fields" , Phil. Trans. R. Soc. A 374, 20160140 (2016) (12 pages)
- M.-J. Huang, J. Schofield and R. Kapral, "A microscopic model for chemically-powered Janus motors" ,
Soft Matter 141, 5581 (2016) (9 pages)
Created September 15, 1997. Last updated September, 2016.