Experiments on transformation microfluidics: cloaking flow and transport without metamaterials

Cloaking effects have now been identified in almost every field of physics. In all cases, substrate-carved metamaterials make the reshaping of the concealed volume impossible. In fluids, recognizing that d'Alembert's paradox describes in itself a hydrodynamic cloaking mechanism, we propose and characterize experimentally a framework to cloak both flow and transport simultaneously within a reshapable fluid volume. The properties of microfluidic cloaks as open-space diffusion filters (O-Filters) are further investigated. They reveal a strong topological analogy with classical H-Filters in microfluidics.