Energy-Smart 3D Fluid Manipulation: Pathways to Low-Carbon Open Microfluidics

We present an energy-smart, transformative approach: a programmable polyhedral frame system governed by capillary forces, which shifts the convention from uncontrollable to precisely designed fluidic interfaces without the need for external pumping. The magnetically actuated capillary container, incorporating steel beads and a 3D polyhedral frame, enables the construction of predefined fluid interfaces in air, water, and oil, allowing for sophisticated manipulations including translation, rotation, and flipping—all achieved without continuous external pumping. Through interfacial gelation, we fabricate freestanding 3D membranes capable of pH-responsive release, as demonstrated with vitamin B₂. By interconnecting these frames via single or double rods, we achieve controlled liquid continuity, forming a reconfigurable “programmable bamboo basket array” that can reversibly capture and release liquids. This system supports 3D multi-fluid patterning, spatiotemporally controlled drug release, and bacterial encapsulation. Furthermore, the open fluid network uses polyhedral frames as chambers and connecting rods as valves, driving continuous flow without external pumping, transforming open architecture into an advantage for low-carbon interfacial engineering: free interfaces support fluid inflow, outflow, and reaction regulation, while increased interfacial areas enhance mass and heat transfer, reducing energy consumption in microfluidic operations. Uniting structural design with capillary programming, this energy-smart system enables precise 3D fluid manipulation and opens new pathways toward low-carbon open microfluidics, with applications spanning micro-nanofabrication, sustainable chemical processes, and biomedicine.