Core–shell particles are micro- or nanoparticles with solid, liquid, or gas cores encapsulated by protective solid shells. The unique composition of core and shell materials imparts smart properties on the particles. Core–shell particles are gaining increasing attention as tuneable and versatile carriers for pharmaceutical and biomedical applications including targeted drug delivery, controlled drug release, and biosensing. This review provides an overview of fabrication methods for core–shell particles followed by a brief discussion of their application and a detailed analysis of their manipulation including assembly, sorting, and triggered release. We compile current methodologies employed for manipulation of core–shell particles and demonstrate how existing methods of assembly and sorting micro/nanospheres can be adopted or modified for core–shell particles. Various triggered release approaches for diagnostics and drug delivery are also discussed in detail.

Micro elastofluidics is an emerging research field that encompasses characteristics of conventional microfluidics and fluid‐structure interactions. Micro elastofluidics is expected to enable practical applications, for instance, where direct contact between biological samples and fluid handling systems is required. Besides design optimization, choosing a proper material is critical to the practical use of micro elastofluidics upon interaction with biological interface and after its functional lifetime. Biodegradable polymers are one of the most studied materials for this purpose. Micro elastofluidic devices made of biodegradable polymers possess exceptional mechanical elasticity, excellent bio compatibility, and structural degradability into non‐toxic products. This article provides an insightful and systematic review of the utilization of biodegradable polymers in digital and continuous‐flow micro elastofluidics.

Liquid beads are core–shell particles with a liquid core and a solid shell. Calcium alginate liquid beads have been emerging as a promising platform for cell encapsulation. These beads have demonstrated their capability of encapsulating and culturing a wide range of human cells for tissue engineering. However, a significant research gap remains in the application of alginate liquid beads for encapsulating photosynthetic microorganisms. Herein, fast‐growing microalgae strain Chlorella vulgaris is encapsulated into calcium alginate liquid beads to facilitate the removal of nutrients from wastewater, minimizing the risk of eutrophication. Liquid bead‐microalgae systems are prepared, using different calcium ion concentrations as crosslinking ions. It has been thoroughly characterized for their morphologies, cell growth patterns, nutrient removal capabilities, and overall stability throughout the wastewater treatment process, with upflow anaerobic sludge blanket effluent as the wastewater model. The results indicate that the liquid bead‐microalgae system with the highest calcium ion concentration (5%) performs more efficiently, exhibiting a well‐formed crosslinking structure, leading to rapid cell growth with the highest cell density and the most effective removal of nutrients. The findings from this study provide valuable insights for future optimization and upscaling efforts in wastewater treatment systems based on calcium alginate liquid beads.

Calcium alginate hydrogel beads are spherical polymeric particles with highly crosslinked network structures, known for their excellent monodispersity and retention capabilities. These beads, produced by high‐throughput droplet‐based microfluidic techniques, are widely used for encapsulating and cultivating various microscopic particles such as cells. While internal gelation has been commonly utilized for crosslinking of calcium alginate hydrogel beads in microalgae encapsulation, the use of external gelation remains underexplored. This study utilized droplet‐based microfluidic technology combined with external gelation to produce calcium alginate hydrogel beads for encapsulating the microalgal strain Chlorella vulgaris. Emulsions containing emulsified calcium ions served as the crosslinking phase. Initial geometrical analysis indicated that beads crosslinked with a high concentration of calcium ions (1 g/mL) achieve superior size uniformity and shape consistency. Microalgae cultivation experiments using these beads demonstrated steady growth of Chlorella vulgaris over a 5‐day period, with the beads maintaining their geometric stability until the final day when minor cell leakage was observed. These results provide a foundation for future molecular‐level studies on microalgae cultivation in hydrogel beads and suggest potential applications in fields requiring precisely controlled microalgae growth.

Combined emulsion‐hydrogel systems offer versatile platforms for controlled release and enhanced emulsion stability across various applications. This study introduces alginate‐based core‐shell structures encapsulating oil‐in‐water emulsions. Mineral oil is emulsified using an aqueous solution containing carboxymethyl cellulose (CMC), calcium lactate, and non‐ionic surfactants (Tween 20 and Span 80) at varying concentrations. The influence of oil volume fraction and surfactant concentration on emulsion stability is assessed through bottle tests, droplet size distribution, and zeta potential analysis. Emulsions with 30 v% oil and 2 wt.% Tween 20 demonstrate the highest stability, remaining stable for up to seven days. The optimized emulsion exhibits a small droplet size of 0.55 µm and a polydispersity index of 15%, indicating a uniform and stable dispersion. This formulation is successfully encapsulated into alginate beads, yielding uniform and spherical structures. SEM imaging shows smooth shell surfaces due to the incorporation of oil, further supported by FTIR analysis. Oil content analysis reveals that larger thin‐shelled beads retain the most oil (25.5%), demonstrating bead morphology influence. Mechanical and swelling tests also show that large, thin‐shelled beads provide superior pressure resistance and swelling capacity. These findings highlight the potential of emulsion‐filled core‐shell alginate beads for applications requiring structural integrity and controlled release.