Ian Wark Research Institute
ARC Special Research Centre
ARC Special Research Centre
Research Area: Nanotechnology, physics, physical chemistry, applied mathematics, chemical engineering
Degree: Honours
Supervisor:
Dr Mihail Popescu
Description: For applications in, e.g., drug-delivery systems or
micromechanics one of the most challenging problems at this stage is to
develop ways to enable small-scale objects to perform autonomous,
controlled motion. One proposal is the use of active particles, i.e.,
objects partially covered by a catalyst that promotes a chemical
reaction in the surrounding medium, the reaction products diffusing
freely in the medium [1]. However, for most of the applications in
biological systems or in 'lab on a chip'-type devices one has to deal
with a complicated internal structure of the systems, such as networks
of narrow channels or pores and various impenetrable impurities;
therefore, one has to understand the effects of a topological
confinement on the motion of such active particles.
Building on our previous studies [2], the project investigates
theoretically the simplest self-induced phoretic motion of a spherical,
active particle (a so called Janus sphere), which is immersed in a
reactive solvent near a wall or in between two parallel plates (a
slit-like channel). The first (and main) aim is to obtain the solution
of the diffusion equation describing the distribution of reaction
products. Depending on the student's progress, the project will continue
with the study of the motion of the solvent (Stokes free hydrodynamic
equations) and of the resulting phoretic velocity.
The project will involve analytical work as well as numerical methods
and/or numerical simulations. A background in physics, chemical
engineering, or applied mathematics is desirable.
References
[1]. see, e.g., R. Golestanian, T.B. Liverpool, and A. Ajdari,
"Designing phoretic micro- and nano-swimmers", New J. of Phys. 9, 126
(2007) and references therein.
[2]. M.N. Popescu, S. Dietrich, and G. Oshanin, "Confinement effects on
diffusiophoretic self-propellers", J. Chem. Phys. 130, 194702 (2009).
