Separation of microspheres using a potential ratchet in dusty plasma

The potential ratchet provides significant flexibility for controlling the transport of charged particles in a desired direction and has been effectively used for particle separation based on size. Here, we design a dusty plasma ratchet that creates a sawtooth-shaped channel with a sufficiently large width, capable of accommodating a substantial quantity of micrometer-sized microspheres (dust particles). Under the influence of the ratchet potential, charged dust particles can be steered to move either in a positive or negative direction along the saw channel, depending on their sizes. The size-dependent transport enables highly efficient particle separation with 100% purity. This device demonstrates the practical application of a potential ratchet in dusty plasma systems, highlighting the potential for precise manipulation and separation of particles based on their sizes.