A detailed study of the interaction between levitated microspheres and the target electrode in a strong electric field

Abstract

In this work, we report on an in-depth study of how 10 μm silica and polystyrene particles interact with a target electrode after they were levitated by applying a strong electric field. The results show that, under these conditions, silica particles unexpectedly have a higher tendency to adhere on a fluorocarbon coated electrode compared to a bare, non-coated silicon electrode. Relative adherence ratios Γ up to Γ = 4.7 were observed. Using the colloidal probe technique, atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), the observations can be explained by a mechanism where particles dissipate their energy through adhesive forces combined with permanent surface deformations during impact and charge transfer through the contact electrification phenomenon. All these processes attribute to increasing the probability that levitated particles attain velocities that are lower than the sticking velocity.