Self-Cleaning Coatings for Space or Earth

The following methods can be used individually or in combination to generate superhydrophobic surfaces: Synthesis of novel copolyimide oxetanes with unique surface properties The technology is the synthesis of a polyimide coating or film with a modified surface chemistry shown in Figure 1. A minor amount of an oxetane reactant containing fluorine is added to the polyimide, and the oxetane preferentially migrates to the surface, enabling relatively high concentrations of fluorine at the surface, without compromising the functional performance of the bulk of the polymide coating/film. The copolymers exhibit mitigation of particle adhesion and fouling from exposure to various particulate and biological contaminants and exhibit reduced surface energy and increased surface fluorine content at extremely low oxetane loadings relative to the imide matrix (see Figure 2). Additionally, the short fluorinated carbon chains do not bioaccumulate, reducing the environmental impact of these materials. Modifying surface energy via laser ablative surface patterning This method uses a laser to create nanoscale patterns in the surface of a material to increase the hydrophobicity of the surface (see Figure 2). The benefits of hydrophobic surfaces include decreases in friction and increases in self-cleaning properties. This is an advantageous method of surface modification because it is fast and single-step, promises to be scalable, requires no chemicals, could be applied to a variety of materials, and does not require a planar surface for patterning.

This durable, transparent, nano-textured coating can be applied via a wet chemistry process to variety of rigid and flexible surfaces by spin coating, brush application, or spray application, making it applicable for many purposes beyond space flight and aeronautical applications. The coatings unique nano-textured surface and overcoat reduces surface energy and contact surface area, giving the coating anti-contamination and self cleaning properties that minimize dust, liquid, and ice accumulation on its surface, similar to a leaf on the Lotus plant. The coating is low outgassing, stable in vacuum, and can survive harsh spaceflight environments. Depending on requirements, the Lotus Coating can be tailored to fit the specific needs of a project or customer. This customization makes the Lotus system far more adaptive, allowing for a more diverse range of applications.

In addition to previous LOTUS coating formulations, an additional optical formulation may be applied via vacuum deposition. This coating forms a top layer and may be applied in different thicknesses that serve to enhance its hydrophobic properties. The vacuum deposited material may comprise fluorinated ethylene propylene or a similar material. This coating is transparent and can be used on optical components or any other applications requiring a clear coating.

NASA’s LESSH BCM is a compact, high-performance, ruggedized system designed to support extended science operations in harsh lunar environments. With a mass of 9.4 kg and dimensions of 50 x 25 x 10 cm, the BCM is engineered for seamless integration with the interface bank on the HLS. A 1.5-meter flexible harness with an EVA-compatible connector and removable dust cover enables reliable operation in austere environments. Astronaut-operated controls, such as a guarded power switch and LED indicators, simplify usability and reduce the potential for errors during high-stakes lunar operations. The BCM is optimized for safety and efficiency, incorporating state-of-the-art power and charging capabilities. It supports charging of 28V astronaut-rated batteries with a power output rated at 215W and integrates a battery pre-heater to maintain optimal performance in extreme temperatures. The BCM features a 4-hour charge time with software adjustability for charging parameters such as current, voltage, overvoltage, and undervoltage setpoints. Battery longevity is ensured through passive rebalancing of cell voltages and advanced safety features. Its 2-fault tolerant hardware and adjustable safety setpoints safeguard against potential hazards. Additionally, the BCM supports 1000BASE-T Ethernet pass-through for high-speed data transfer. Originally designed to extend the length of lunar surface science experiments by enabling astronauts to recharge instrumentation, NASA’s LESSH BCM may be desired by companies seeking to operate sensors on the lunar or Martian lunar surface. The design may also be suitable for terrestrial applications involving harsh environments where interchangeable sealed sensors must operate on their own or with rovers, robotics, and drones. The BCM is at technology readiness level (TRL) 4 (component and/or breadboard validation in lab) and is available for patent licensing.

While HEPA filter elements can last for years without intervention, pre-filtering systems that remove larger particles before they reach the HEPA filter need to be treated (most often by cleaning or replacement) as often as once a week. These treatments can be resource-intensive and expensive, especially in extreme environments. Glenn's innovative system combines a pre-filtration impactor and a scroll filter that reduces the need to replace the more sensitive or expensive filters, extending the system's working life. The system uses an endless belt system to provide the impaction surface. A thin layer of low-toxicity grease is applied to the impaction surface to increase particle adhesion. A high flow turning angle near the impaction surface causes relatively large particles to impact and stick to the surface while smaller particles stay within the air flow. When the surface is covered with particles - or if a layer of particles has grown to a thickness that impairs adhesion - the surface is regenerated. The band is rotated so that the loaded surface passes by a scrapper, removing the layer of particles and a clean segment of the band revolves to become the new impaction surface. A further innovation is the scroll filter which allows the filtration media to be rotated out of the airflow when fully loaded, providing multiple changes of the filter through a motorized scrolling or indexing mechanism. When nearly fully loaded with dust particles, the exposed media is mechanically rolled up on one side of the filter to both contain and compactly store the dust. The spools that hold the clean and spent filter media are mounted on roller bearings to facilitate the scrolling operation and reduce motor power requirements. Nearly any grade of filter media can be used to meet the desired filtration specification. Additional media rolls can be added after the original roll is spent to further increase filter life.