Effective extreme viscosity anisotropy enables environment-adaptive and geometry-arbitrary hydrodynamic metamaterials
Phys. Rev. Fluids 11, 064101 – Published 22 June, 2026
DOI: https://doi.org/10.1103/7r2w-vzyj
Abstract
Hydrodynamic metamaterials offer novel strategies for liquid control, enabling local regulation of flow without disturbing the background field. However, existing passive designs are typically constrained by fixed working environments and regular geometries, which severely limit their applicability in complex scenarios. Here, we demonstrate a hydrodynamic metadevice that features both environment-adaptive and geometry-arbitrary properties. These unique capabilities arise from exploiting extreme viscosity anisotropy in Hele-Shaw flows, which can be effectively achieved through the structural design of microchannels. Numerical simulations and experiments verify that our metadevice with arbitrary geometry robustly preserves the background flow while increasing the central velocity, even under varying environmental conditions. This design framework extends the flexibility and robustness of hydrodynamic metamaterials for complex and dynamic environments, laying the groundwork for advanced microfluidic control.
