Description: Significant challenges remain for the designers of life support equipment for spacecraft—primarily for the processing of aqueous fluids: oxygen supply, air revitalization, thermal management systems, water reclamation, medical fluids, and others. The main problem is that failure-prone processes are often employed to overcome unfamiliar microgravity fluidic phenomena using artificial buoyancy-inducing methods. The most obvious example is a mechanical centrifuge for liquid-gas separations aboard orbiting spacecraft. To improve NASA's spacecraft fluid systems design, InnoSense LLC (ISL) proposes to develop Superhydrophilic Coatings for Embedded Capillary Systems (SPHIL-EMCAP) with anti-microbial properties. In Phase I, ISL will design and fabricate a complex capillary solution for spacecraft fluid management. The geometric design will exploit the current state of the art in analytical and computational capillary fluidics. Devices will be coated with SPHIL-EMCAP and evaluated for substrate adhesion, water contact angles, wear, and environment robustness, before testing in the relevant low-g environment to assess the improved capillary control afforded by the superhydrophilic coatings. In Phase II, ISL will downselect materials and applications, and optimize SPHIL-EMCAP's performance by refining the prototyping process and optimizing the superhydrophilic coating formulation. We will perform extensive characterization toward manufacturing a miniaturized SPHIL-EMCAP.

Benefits: Long-duration space flight on ISS and on flights anticipated for the moon, Mars and other planetary missions will require hardware that is less prone to failure and generally more sustainable than the current state of the art. The spacecraft fluid systems that could benefit from control of wetting are manifold and include systems for air revitalization, water recovery, water management, habitation, cryogens, and propellants. Important and historically challenging applications include phase separations common to waste water treatment facilities (i.e., urine), condensing heat exchangers, and many other contaminating systems such as those related to plant and animal habitats, laundering and hygiene, food rehydration and dispensing, and others that are necessary to close the water cycle.

The major commercial market for SPHIL-EMCAP is micro-fluidic based lab-on-a-chip diagnostics, which is part of the larger biochip market. Another potential market is biofilm prevention on medical and dental devices. A number of approaches, including hydrophilic and hydrophobic coatings, are being looked at to help solve this problem. Modification of the SPHIL-EMCAP coating for this type of application falls into the anti-microbial coatings market. The proposed innovations offer the potential for abrasion resistant anti-fog and anti-reflection coatings on both glass and plastic surfaces. The coatings are made by industrially viable coating method suited to forming conformal coatings. Other potential applications include aviation, automotive, sporting equipment, military vehicle and displays and healthcare sectors.