论文标题
具有表面运动酶的活性颗粒的自发极化和运动
Spontaneous polarization and locomotion of an active particle with surface-mobile enzymes
论文作者
论文摘要
我们检查了活性颗粒的运动机制，其表面均匀地涂有移动酶。这些酶催化了驱动整个流动的反应，但它们的均匀分布禁止通过对称性进行运动。我们发现，酶在表面上迁移并结合自晶的能力会导致自发的对称性破坏不稳定性，从而使酶的均匀分布极化和颗粒驱动。不稳定性是由酶的对流驱动的，并在关键的péclet数字之上发生。向极化流动状态的过渡是通过超临界或亚临界干草叉分叉发生的，后者可以实现均匀和极化状态的滞后和共存。
We examine a mechanism of locomotion of active particles whose surface is uniformly coated with mobile enzymes. The enzymes catalyze a reaction that drives phoretic flows but their homogeneous distribution forbids locomotion by symmetry. We find that the ability of the enzymes to migrate over the surface combined with self-phoresis can lead to a spontaneous symmetry breaking instability whereby the homogeneous distribution of enzymes polarizes and the particle propels. The instability is driven by the advection of enzymes by the phoretic flows and occurs above a critical Péclet number. The transition to polarized motile states occurs via a supercritical or subcritical pitchfork bifurcations, the latter of which enables hysteresis and coexistence of uniform and polarized states.
