Dust-Resistant Pressure Seals Utilizing Ferrofluids

Dust mitigation remains a critical challenge in space exploration in general and for systems exposed to abrasive lunar regolith in particular. Spacesuit pressure garment seals are especially vulnerable, with traditional rubber O-ring designs prone to damage and degradation by scratching. A novel sealing technology with strong industrial heritage using ferrofluids – magnetic liquids consisting of nanoscale iron oxide particles suspended in a hydrocarbon carrier liquid – is presented as a solution. Ferrofluids offer unique advantages, including the ability to form dust-repelling, atomically tight seals under the influence of magnetic fields. The ferrofluid in the presence of a magnetic field actively repels non-magnetic particles such as lunar regolith or gases, utilizing the created magnetic pressure to maintain a clean seal. On Earth, ferrofluid seals are widely used in vacuum chamber systems, including physical vapor deposition (PVD) processes, where they ensure contamination-free environments and high-performance sealing. Using a combination of fixed and movable permanent magnets, ferrofluid-filled channels create a durable seal capable of withstanding pressure differentials up to 30 kPa per seal barrier. For applications requiring higher performance, multiple seals can be stacked to accommodate a pressure differential of ambient-to-vacuum conditions or serve as additional operational safety margin. The liquid nature of ferrofluid ensures quasi-frictionless rotational motion, minimizing wear on the sealing surfaces as well as allowing for comfortable operation for a human user. Movable magnets allow the ferrofluid to be redirected into integrated reservoirs during donning and doffing, enabling ease of operation without compromising integrity. Preliminary tests on an unpressurized prototype demonstrate the feasibility of this technology. Future work will focus on refining the design for operational pressures and integrating the seals into functional spacesuit components. By mitigating dust intrusion and enhancing seal durability, this ferrofluid-based approach addresses a critical need in sustaining long-term lunar exploration.