Maqbool, FaisalFaisalMaqboolLu, Guan-YuGuan-YuLuYA-YU CHIANG2026-01-152026-01-152026-01-251226086Xhttps://www.scopus.com/record/display.uri?eid=2-s2.0-105024342607&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/735348Parallel flow typically exhibits inefficient mixing due to viscous-dominated laminar regimes, limiting biphasic mass transfer to interfacial molecular diffusion. To overcome this fundamental constraint, we engineered a novel core-annular microextractor featuring a rectangular helical wire core. This unique passive geometry inherently induces controlled vortices directly at the liquid–liquid interface without external energy input. Multiphysics simulations revealed that specific gap widths combined with the helical topology trigger vortex formation as the aqueous phase interacts with the wire pillars, significantly disrupting the diffusion boundary layer. Fluorescent particle tracking experimentally confirmed these interface-proximal vortices, validating the simulation. Crucially, this passive vortex-driven mass transfer mechanism directly enhances interfacial renewal and mixing efficiency. In proof-of-concept extraction of acetophenone/n-heptane systems, the structurally induced vortices within the optimized gap achieved 68.18% acetophenone extraction efficiency, demonstrating how tailored microfluidic architectures can passively amplify mass transfer via localized hydrodynamic manipulation.falseCFDExtractionFlow ChemistryMass transferPassive mixingVortexjournal article10.1016/j.jiec.2025.10.0182-s2.0-105024342607