Removal efficiency for size-sorted particles of lunar regolith simulant using an electrodynamic dust shield

Abstract

Mitigation of lunar regolith particles is one of the challenges for the success of future lunar exploration, and an electrodynamic dust shield (EDS) presents a promising solution. Although a wide range of investigations have been conducted on the cleaning of lunar regolith and its simulants using EDS, the effects of particle size on cleaning performance have not been experimentally investigated in depth. In this study, we conducted EDS cleaning experiments using simulant particles sorted into different size ranges, with the aid of force balance calculations that vary with particle size. The experimental and calculated results reveal a clear trend: the cleaning performance of simulant particles smaller than 25 μm and larger than 250 μm deteriorated owing to the adhesion force of small particles and the dielectrophoresis and gravitational forces of large particles, respectively. In addition, observations of particle motion using a high-speed camera confirmed the role of dielectrophoresis and Coulomb forces on regolith simulants of various sizes during cleaning. In the effects of the dielectrophoresis force on larger particles, the interactions of polarized particles were clearly visible, resulting in the creation of particle chains and the trapping of particles on the substrate surface of EDS.