Project Summary

Fluctuations become very significant as system sizes decrease, and therefore are important in understanding the properties and behaviour or nanoscale systems. Observation of the distribution of fluctuations can also be used to measure properties of systems that are difficult to determine in other ways.

This project involves use of fundamental science to develop new relationships applicable to small systems. We have developed new statistical mechanical relationships that are applicable near and far from equilibrium that both characterise the fluctuations and can be used to derive exact relationships in nonequilibrium thermodynamics.

Le Chatelier’s principle states that when a system is disturbed, it will shift its equilibrium to counteract the disturbance. However for a chemical reaction in a small, confined system, the probability of observing it proceed in the opposite direction to that predicted by Le Chatelier’s principle, can be significant. This can be quantified by the fluctuation theorem, given by the equation in this figure.  This result was tested using computer simulations of the unfolding of a polypeptide due to a change in temperature.
Nanoscale systems model


Research Group

Bernhardt Group


Nonequilibirum systems, Fluctuations, Free energy calculations, Solubility, Phase changes, Properties of nanoscale systems, Transport processes, Jarzynski Equality Fluctuation Relations, Nanomaterials, Manufacturing, Materials, Nanobiotechnology

Student Projects

Application of fluction theorems to physical and chemical problems.

The role of dissipation in nonequilibrium statistical mechanics.

Project members

Professor Debra Bernhardt

Senior Group Leader
Bernhardt Group
CTCMS Director
AIBN Deputy Director (Research)

Marsel Gokovi

PhD Student
Bernhardt Group

James Reid

Research Fellow
Bernhardt Group