Performance of chemically modified reduced graphene oxide (CMrGO) in lunar electrodynamic dust shield (EDS) applications

Abstract

Electrodynamic Dust Shield (EDS) technology is a dust mitigation strategy that is commonly studied for rigid applications such as photovoltaics or thermal radiators where soiling of the surfaces can reduce performance. The goal of the current work was to test the performance of a flexible, patterned nanocomposite EDS system produced through spray-coating and melt infiltration of chemically modified reduced graphene oxide (CMrGO) traces with thermoplastic high-density polyethylene (HDPE). The EDS performance was tested for a dusting of lunar regolith simulant under high vacuum conditions (∼10−6 Torr) using both 2-phase and 3-phase device configurations. Uncapped (bare) devices showed efficient dust removal at moderate voltages (1000–3000 V) for both 2-phase and 3-phase designs. Further tests carried out while illuminating the dust surface with a UV excimer lamp showed that the EDS voltage needed to reach the maximum cleanliness was reduced by almost 50% for the 2-phase devices (500 V minimum for rough and 1000 V for smooth), while the 3-phase devices were unaffected by the application of UV. However, the performance of the uncapped devices degraded after several sequential tests due to erosion of the traces caused by electric discharges and dielectric breakdown. Capping the CMrGO traces with low-density polyethylene (LDPE) eliminated breakdown of the materials and device degradation, but larger voltages (3000 V) coupled with UV illumination were required to remove the grains from the capped devices.