Hierarchical branched structures exist in nature in diverse forms, functions and scales stretching from micro to very large sizes. Typically effective as heat and mass transfer networks, ordered hierarchal/ multiscale branched/ tree-like networks could be fabricated by controlling a fluid reshaping process in a device called 'Multiport Hele-Shaw cell'. Control over the instability by employing micro-modified cell plates, containing 'source-holes' as ports, rearranges the fluid into ordered tree-like networks. Reshaping is an outcome of 'Saffman-Taylor interface instability' induced by the displacement of a high-viscous fluid by a relatively low-viscous one in the cell. A new configuration of 'source-holes', is proposed here to control the instability towards shaping of high-viscous fluid into ordered multiscale treelike layouts. The process is lithography-less method of shaping the fluid spontaneously into 3D layouts in a very short interval of time. Fabricated structures are UV-cured and cast into channel-networks in an elastomer PDMS.
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