Using Langevin simulations, we numerically investigate the dynamics of driven two-dimensional colloids subject to randomly distributed pointlike pinning centers. Increasing the strength of pinning centers, we find a crossover from elastic to plastic depinnings, where a substantial increase in the depinning force is observed. The influence of temperature is examined, and we find a dynamic melting transition from the moving smectic to the moving liquid at high driving forces. A peak is found in the dynamic critical driving force across the transition, accompanied by a crossing of velocity-force dependence curves.

The formation and properties of stable charged-grain clusters are followed using molecular dynamics simulation. It is found that uniformly distributed grains with random velocities can form clusters of different thermodynamic states within the same system. The formation process and the dependence of the number and types of clusters in the statistically asymptotic state of the system on the initial grain temperature and density are investigated.

The clustering process of charged grains often resembles a formation stage of colloidal and spongy matter, as well as some astrophysical objects. In this paper, molecular dynamics simulation is used to simulate the formation process of clusters of massive charged grains in plasmas. It is found that, from an initially uniform distribution of grains with Maxwellian velocity distribution, a statistically stationary system of clusters, each with different dynamic as well as thermodynamic characteristics, can form. The dependence of the asymptotic, of the final, state of the cluster system on the initial temperature and density of the grains is discussed.

Evolution of the spatial structure of the massive charged grains in the presence of weak linearly space-dependent external force in a dusty plasma is studied using molecular dynamics simulation. The interaction among the dust grains in the background electron-ion plasma is described by a modified Yukawa interaction potential that includes both repulsive and attractive ranges. Evolution of the initially homogeneously distributed dust grains is followed until a quasi-stationary state is reached. Even though the external force is radially highly asymmetric, the final configuration of the charged grains can be a circular crystal. Still driven by the external force, the grains in the crystal execute synchronized oscillations in the direction of the force. The time needed to reach the quasi-stationary state decreases with increase of the strength of the external force.