As the most exciting research branch in condensed matter physics, soft matter or even newly shaping active matter physics, the units in the active system extract energy from their surroundings at microscopic level towards to mechanical motion. These active or living systems display very rich physics, with features not observed in passive systems, which is inherently far from equilibrium where, the statistical physics framework commonly used to describe soft matter systems breaks down, and new theory is needed.

Recently, we mainly focus on:

·      Spreading of tiny liquid drops on versatile surfaces.

·      Self-assembly under capillary regimes for passive and active matter.

·      Interaction of flexible filaments with living flow and bio-turbulent flow.

·      Collective motion of self-propelled particles, and a new-kind of Living Hall effect.

Fig1. 微流控PDMS管道中细菌趋流运动显微观测。控制参数为Flow rate，与高度h，两者同时确定细菌所处位置的局域剪切率，流场为泊肃叶流，在宽度方向上可以认为剪切恒定（除了侧壁附近区域），而高度方向（z）线性剪切。定义导航角为\Psi, 仰角为\theta.

Fig2. 实验发现细菌在剪切流中，细菌的趋流沿着涡度（vortocity）方向，即正剪切（半高度以下部分）细菌游向左侧，而负剪切部分细菌游向右侧，且在低剪切下，细菌的趋流偏移速度vy与剪切率成正比。