Experimental investigation of surface adhesion of Titan analog materials: Mitigation by dust-repellent coatings

Abstract

We report an experimental investigation of organic Titan regolith simulant interactions with transparent surfaces. In the absence of prior triboelectrification of the particles and surface, the area coverage of sprinkled particles increases with increasing substrate surface energy, as expected. Bare sapphire, sapphire coated with indium tin oxide (ITO), and sapphire coated with ITO and fluorosilane collected 20%, 10%, and 5% particles, respectively. Under turbulent conditions that promote triboelectric charging, the adhesion of Titan regolith analogs is enhanced. Bare sapphire occluded by more than 60% in some cases. However, conductive ITO generally reduced the area coverage below 10% when electrically grounded, and the fluorosilane treatment reduced it slightly further. The surface coatings tested, and anti-static measures more generally, therefore provide significant mitigation of optical window contamination.