Fluid transport and handling in extraterrestrial conditions, i.e. microgravity, require significantly different system engineering than here on Earth. On Earth, a notable part of fluid processing units inherently relies on buoyancy to transport and handle fluids. In space, however, buoyancy effects are negligible due to the strong diminishment of gravity, resulting in the domination of surface tension forces. Surface tension forces are also dominating micro-scale processes in gravity, making microfluidics a promising technology for fluidic transport and handling in microgravity. Recently, three different microfluidics-suitable fluid behavior phenomena have been studied on the ISS that might further facilitate the manipulation of fluids in space: capillary-driven flow, thermocapillary Marangoni forces, and electrolytic gas evolution-driven flow. Furthermore, attention is drawn for strategies to eliminate unwanted bubbles from liquid bodies in space, as they can damage sensitive equipment: Mesh-screen capillarity and open wedge channels have been identified as promising approaches. Finally, the relevance of fluid handling in space is illustrated with everyday activities during space missions, such as drinking, plant watering, and gathering biometric data.

Nanostructured products are an actively growing area for food research, but there is little information on the sustainability of processes used to make these products. In this Review, we advocate for selection of sustainable process technologies during initial stages of laboratory-scale developments of nanofoods. We show that selection is assisted by predictive sustainability assessment(s) based on conventional technologies, including exploratory ex ante and “anticipatory” life-cycle assessment. We demonstrate that sustainability assessments for conventional food process technologies can be leveraged to design nanofood process concepts and technologies. We critically review emerging nanostructured food products including encapsulated bioactive molecules and processes used to structure these foods at laboratory, pilot, and industrial scales. We apply a rational method via learning lessons from sustainability of unit operations in conventional food processing and critically apportioned lessons between emerging and conventional approaches. We conclude that this method provides a quantitative means to incorporate sustainability during process design for nanostructured foods. Findings will be of interest and benefit to a range of food researchers, engineers, and manufacturers of process equipment.

The use of microfluidics for oil‐in‐water (O/W) nanoemulsification via spontaneous self‐assembly is demonstrated. As this is known to be a longish process, both single‐ and multicontact microfluidic reactors are tested, the latter providing a longsome, constant microfluidic treatment to maintain advanced phase and interfacial mass transfer. Microfluidic devices provide strong advantages above conventional systems for spontaneous emulsification, with droplet sizes of 62 nm at desired surfactant‐to‐oil ratios (SOR) and a decrease of 90% in process time. Multicontact microfluidics have better performance than their single‐contact counterparts, while critical aspects, e.g., process robustness, are also discussed. Ternary phase diagram analysis of the three components (oil, water, surfactant) allow to decide for the right mixing ratio and sequence of mixing steps for the nanoemulsions. Microfluidic spontaneous emulsification meets objective functions of the intended application to provide fortified beverages to astronauts in space exploration. In that viewpoint, an advantage is to achieve stable nanoemulsions at a level of concentrations much higher as compared to application (human intake), allowing a dilution factor to the final product of up to 100. This decreases notably the process time and allows for process flexibility, e.g., to dilute or tailor Earth‐prepared nanoemulsion concentrate payloads in space.