Metafluidic shaping: Simultaneous flow uniformity and drag reduction

Disordered flow patterns and elevated resistance at abrupt geometric transitions are critical issues in systems from blood vessels to microfluidics, where they are linked to disease and inefficiency. Conventional flow control strategies face a fundamental dilemma: efforts to reduce drag often disrupt flow uniformity, while attempts to rapidly stabilize the flow typically increase resistance. Here, we introduce a metafluidic shaping strategy that overcomes this limitation, enabling simultaneous drag reduction and rapid flow stabilization. Inspired by metamaterial concepts, we treat the geometric transition as a dipole scatterer and deploy auxiliary structures to generate a counteracting flow field, effectively canceling adverse hydraulic effects. Experimental visualizations confirm the complete suppression of local recirculation, leading to highly uniform flows with substantially reduced drag. Furthermore, applying this technique to liquid cooling plates significantly enhances thermal performance, yielding lower and more homogeneous temperatures. Our work demonstrates that a metamaterial approach can overcome fundamental limitations of traditional fluid dynamics.