Alginate-based sustainable process to augment the aspect ratio of low-melting-point alloy microparticles

초록

The morphology of microparticles has emerged as a critical parameter in enhancing their functionality. Geometric characteristics enable microparticles to overcome limitations inherent in spherical counterparts. However, conventional strategies for transforming spherical particles into ellipsoidal ones face substantial impediments due to surface tension. While top-down approaches that solidify liquid precursors into discrete particles are scalable, the surface tension of these precursors impedes the formation of non-spherical droplets at the microscale. In this study, we introduce an eco-friendly and scalable process that overcomes dominant surface tension to fabricate high–aspect ratio microparticles. This process leverages the reversible cross-linking of alginate polymers, whose mechanical modulus can be tuned on demand: exhibiting solid-like behavior during particle fabrication and liquid-like behavior during particle retrieval. Using this method, a low–melting point alloy (Field's Metal), noted for its high surface tension, is successfully converted into ellipsoidal microparticles with an aspect ratio of >4. The mechanics underlying this process and the potential applications of the ellipsoidal particles are also discussed to provide deeper insight into the fabrication method. © 2026 Elsevier B.V.

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