Microfluidics is a powerful technique for fabricating hydrogel microspheres with controllable morphology, however microsphere topologies are strictly defined by the hard device structure. Herein, we present a simple microfluidic electrospraying technique to synthesize magnetic hydrogel microspheres with diverse structures without changing devices. This method used microfluidic laminar flow controlled by interfacial tension as a soft template. Guided by theoretical analysis and simulation, we could adjust the two-phase laminar flow template to control the microstructure of microspheres from Janus to core–shell topologies. Importantly, this soft-template method is applicable to a broad range of materials and involves only aqueous solutions. Furthermore, the potential use of this technique is explored for generation of complex topological microspheres from three phase fluids. Finally, we validated the unique advantages of these microspheres in controlled drug sequential release. This microfluidic method demonstrated that microscale laminar flow can be used as a soft template for fabrication of microspheres.

中文翻译：

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微流控器件中磁性微球拓扑结构的软模板调控


微流体是一种强大的技术，用于制造具有可控形态的水凝胶微球，但微球拓扑结构严格由硬器件结构定义。在此，我们提出了一种简单的微流体电喷雾技术，可以在不改变设备的情况下合成具有不同结构的磁性水凝胶微球。该方法使用由界面张力控制的微流体层流作为软模板。在理论分析和仿真的指导下，我们可以调整两相层流模板来控制从 Janus 到核壳拓扑结构的微球微观结构。重要的是，这种软模板方法适用于广泛的材料，并且只涉及水溶液。此外，还探索了该技术在从三相流体生成复杂拓扑微球方面的潜在用途。最后，我们验证了这些微球在控药序贯释放中的独特优势。这种微流体方法表明，微尺度层流可以用作制造微球的软模板。