Institute of Physics, Academia Sinica

Polymer Physics and Complex Fluids Group


The Polymer Physics and Complex Fluids Group actively develops novel methods for investigating the equilibrium and non-equilibrium properties of complex particles and complex fluids. We develop and employ cutting-edge theoretical and computational tools to understand the complex interplays within complex fluids, including polymer and biopolymer solutions, extra- and intra-celluar dynamics, and highly confined polyelectrolyte systems.

Currently, advanced simulation models are able to capture the thermodynamics and dynamics of molecules on the nanoscale, while continuum models have been successful in describing material mechanics on the bulk scale. However, a bridge linking the nanoscale to the bulk properties is direly needed. Our group aims to develop multi-spatial/temporal scale methods that seek to link nanoscale properties to microscale mechanics, and microscale mechanics to macroscale phenomena.

Here is a live demo for a semi-flexible polymer in a nanoparticle solut ion confined between two walls. You can try to change the parameters to condense the polymer into a globule, adsorb polymer to th e wall, or expand the polymer size.


Equilibrium and non-equilibrium polymer dynamics

Polymer materials are everywhere, they are found in the materials that construct the keyboard we type on to the biological building blocks of our body (DNA, cell membranes). Their properties depend on their chemical composition, topology, size, density and the surrounding matrix. Our group explores the properties of these wonderful molecules in solution.

Dynamics of soft particle suspensions in flow

We are interested in the similarity between the dynamics of blood cells in flow and the dynamics of polymers in flow. It has been known for more than 100 years that blood is a complex, non-Newtonian fluid, with properties that depend on the concentration of blood cells. We develop novel methods to study the effects of particle deformation on flow properties.

Coarse-grained model for DNA dynamics on the micron / millisecond scale

Coarse-grained polymer models are coupled with the fluid dynamics equations are employed to investigate the complex behavior of DNA molecules in microfluidic flow and under electric fields. We found mechanisms for concentrating DNA molecules in flow, which could lead to non-Newtonian fluid rheology, as well as mechanisms for focusing and trapping DNA molecules using counter-rotating vortices.