Imperial College London


Faculty of Natural SciencesDepartment of Mathematics

Professor of Statistical Physics



+44 (0)20 7594 8537a.o.parry Website




6M15Huxley BuildingSouth Kensington Campus





Statistical Mechanics is the go-to tool that Theoretical Physicists use to explain the macroscopic world around us using a microscopic starting point of atoms and molecules.  I use Statistical Mechanics including techniques such as Density Functional Theory,  Scaling, The Renormalization Group and Transfer Matrices to study the wonderful world of Phase Transitions and Critical Phenomena involving Fluid Interfaces - this is the stubborn attempt to understand all things related to the surface tension from a properly microscopic perspective. There are many applications to important new nano-technologies including microfluidics, but also, from a more fundamental perspective we have learnt about the sensitive interplay between intermolecular forces and interfacial fluctuations. In other words imagine that at the microscopic scale the surface of a drop is sharp because of the imbalance of atomic forces but simultaneously is doing a kind of random walk because its being bombarded by atoms from above and below. This microscopic perspective is crucial to understanding why a macroscopic drop on a surface has a well defined angle of contact and explains why the drop can suddenly spread out (wet) the surface as the temperature is increased to a wetting temperature. We can also predict what happens to drops on structured surfaces (hence the connection with microfluidics) and here we have found how the interplay with substrate geometry can dramatically alter the macroscopic physics. Indeed this reveals new types of phase transition and completely unexpected hidden symmetries which precisely relate fluid adsorptions on different surfaces.

Invited Lectures and Presentations

  • In 2012 I was awarded a Chair of Excellence at the Universidad Carlos III de Madrid.
  • Recent and forth coming invited talks include;
  • January 2013 Gottingen " Capillary Emptying and Short Ranged Wetting"
  • March 2013 Madrid " Interfacial Phase Transitions at the Micro and Macroscopic Scale"
  • June 2013 Lisbon " Capillary Emptying and Short Ranged Wetting"
  • June 2013 Madrid " Wetting, Filling and Spilling" (Chair of Excellence Lecture)
  • August 2013 Leuven " The Intrinsic Interface and Non-local Interfacial Fluctuations"

Other Significant Activities

I am a Fellow of the Institute of Physics and sit on the Strategic Science Advisory Committee of the IoP.

Research Student Supervision

Willis,G, Fundamental Statistical Mechanics of Inhomogeneous Fluids