Crystallization for Manufacturing in Microgravity; Are We There Yet?

Abstract

Crystallization in microgravity has been extensively investigated because of its potential to enhance crystal quality compared to terrestrial conditions. While early efforts were primarily directed toward single-crystal growth for structural studies, increasing attention is now being given to its relevance for manufacturing in low-Earth orbit (LEO) and future in-space manufacturing (ISM). This review provides a structured and systematic analysis of the literature on microgravity crystallization by examining the materials studied, distinguishing between single-crystal and bulk crystal regimes, and evaluating the experimental methodologies used to investigate crystallization kinetics. Emphasis is placed on the current platforms. By adopting a manufacturing perspective, this work identifies key challenges and outlines directions for advancing microgravity crystallization toward scalable and controlled processes for manufacturing under microgravity. To date, the current body of literature remains fragmented and insufficiently aligned with process engineering and manufacturing considerations, including restricted in situ monitoring, a lack of standardization, and limited comparability across studies.