Anti-Fog Coatings for Spacesuit Helmets

Date

2024-07-21

Journal Title

Journal ISSN

Volume Title

Publisher

2024 International Conference on Environmnetal Systems

Abstract

The purpose of this project is to demonstrate the feasibility of applying a permanent anti-fog coating on the interior of polycarbonate spacesuit helmets. Two types of coatings are explored in this project: 1) A superhydrophobic Diamond Like Carbon (DLC) coating and 2) a superhydrophilic DLC Coating. Both coatings are extremely durable and are not affected by common laboratory solvents, such as IPA, or cleaning solutions. The coatings consist of an optically transparent diamond like carbon applied using a 2-step plasma processing technique to achieve an anti-fog, self-cleaning, DLC layer. The all-dry deposition process consists of an oxygen plasma pre-treatment to engineer the polycarbonate, creating a well-controlled nanotextured surface, followed by Plasma Enhanced Chemical Vapor Deposition (PECVD) of the DLC layer. The difference between the superhydrophobic and superhydrophilic DLC coatings is determined by adjusting the oxygen plasma pre-treatment and PECVD coating parameters. Water Contact Angle (WCA) measurements are performed and for the superhydrophobic DLC is >150° and for the superhydrophilic is ~ 0°. The coatings are tested using a breathing simulator at 18 cycles/min for 216,000 cycles (200 hours) to test for degradation or changes in the coating properties and are shown to be very durable. The coatings are also subjected to cross-hatch tape-pull adhesion testing, 100 cycle-wipe cleaning tests, IPA exposure testing, abrasion testing, and optical transmission measurements. All of the tests are conducted both before and after the 200 hour simulated breathing exposure to demonstrate the durability of the DLC coatings.

Description

Mike McFarland, Acree Technologies Inc., USA
Kelvin Wong, Acree Technologies Inc., USA
ICES400: Extravehicular Activity: Space Suits
The 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.

Keywords

Spacesuit, Helmet, Anti-fog

Citation