Abstract:

Research on diffusion behaviors in micro-scale confined space is of significant value in micro-chemistry. In this work, we have constructed a model of miniature single-channel separation system, which was made of inversely asymmetric Brownian ratchets, and conducted simulations of molecular diffusion in this system based on random walk theory. The separation mechanism and the influence of different conditions on the diffusion behaviors were discussed based on the simulation results. It was concluded that, interaction between the particle and the Brownian ratchets could be adjusted by the switching time of the external force properly, which enables different particles separated into two different directions in the single-channel system. The applicable conditions of this separation system was provided as well. Furthermore, it was demonstrated that with adjustment of the structural parameters of the separation device, time cost of the separation process could be saved effectively while achieving optimal separation. The simulation method has certain reference significance for the development of micro-separation devices and optimization of the operating parameters.

Key words: Brownian ratchet, Diffusion, Separation, Random walk, Simulation