There has been rapid development in research on self-organization of active materials in non-equilibrium material systems. Differing from equilibrium material systems, active material in non-equilibrium systems, including all life forms from single cell to animals, biomolecules driven by molecular motors and self-fueled material created by artificial synthesis, has partial energy input. Recently, a team of physicists of the Chinese University of Hong Kong (CUHK), the University of California and Harvard University made a breakthrough in this field: the viscoelasticity of material can control the self-organization of active fluids in space and time. This research achievement was published in the journal Science. Professor Wu Yilin of CUHK is the corresponding author of the paper. Liu Song, a graduate of Xi'an Jiaotong University, is the first author of the paper.

The research verifies that an active material's rheological property can be used to control its self-organization for the first time. The results promote the development of non-equilibrium physics. Microbes usually move in an environment full of viscoelastic polymers of the natural world such as animal digestive tracts. The research suggests that the rheological environment may affect the collective diffusion and migration of microbial communities.

Liu Song was admitted to the Xi'an Jiaotong University physics experimental class in 2010 and began studying for his doctoral degree at CUHK in 2014.