Description: Brine de-watering is the final unit operation required to close the water cycle for life support aboard spacecraft. Though no such system has been demonstrated in space to date, numerous methods have been proposed and developed to various degrees. In this Phase I effort we propose to develop a versatile microgravity-compatible brine de-watering method that exploits the Brine Residual in Containment (BRIC) approach. The system is essentially passive, employing the combined effects of surface tension, wetting, and system geometry to drive and stably support the fluids involved. Our approach balances performance with simplicity, the latter which leads to a safe, clean, low-cost, fast-to-flight device with high probability of success. The broad solution approach is expected to be tolerant of pretreatments, contaminates, particulates, and widely varying input feed lines. Preliminary data suggests that the compact and lightweight approach requires only ~0.02kg of disposable support material for ~1L (~1.8 kg) of solid brine produced, and that maintenance expectations are as low as 30 minutes per 50 days per crew member. Our Phase I deliverable is a low-g drop tower-demonstrated prototype with a clear plan for rapid construction and flight qualification of a flight version for verification and validation aboard the International Space Station.

Benefits: The capillary BRIC technology for brine dewatering is a critical and urgent item for life support aboard spacecraft. It is envisioned that NASA will be a prime user of the proposed technology and serve as both collaborator and customer of said devices. In addition to qualification, fundamental data concerning capillarity, phase change, and stability may be useful for other space-based applications involving drying or de-watering.

Commercial aerospace companies are currently developing life support capabilities that will also require closing the water cycle. In this light, the proposed work is directly applicable to commercial spaceflight as well. On the ground our research has applications to large scale passive fluidic operations for dewatering algae for H2 production, advanced microfluidics for water management in fuel cells, lab-on-chip devices, and porous structures for scaffolds in tissue engineering.