A 2D Shaping 3D Strategy to Construct Hierarchical Microstructures Based on Heterogeneous Wettability

Abstract Through rational design and elaborate preparation, simple materials can be evolved into microstructures with 3D morphology. Benefiting from their unique morphology and composition, these 3D microstructures exhibit exceptional optic/electric properties that surpass those of their building blocks. Self‐assembly relies on control of liquid behavior and morphology, and can efficiently aggregate building blocks into ordered microstructures. However, under the principle of surface energy minimization, the self‐assembled microstructures are constrained by limited morphology and monotonous component. Herein, the assembly of microstructures with controllable morphology and composite components is achieved, through effectively controlling 3D liquid behaviors and morphologies using 2D heterogeneous wettability. It is revealed that the heterogeneous wettability surface can induce stepwise liquid behaviors, which rapidly split suspension into isolated liquid bridges, then gradually shrink for 3D assembly. Through surface wettability control, this strategy not only extends into a printing‐like approach to deposit microstructures on target surface, but also facilitates the fabrication of composite microstructures with multi‐components. Taking advantage of the 3D morphology, the heterogeneous wettability, and the multi‐components, the resulting composite microstructures exhibits ultra‐sensitive detection capability. It is anticipated that this 2D‐shaping‐3D strategy opens a facile avenue to fabricate hierarchical microstructures for optic/electronic and sensing applications.