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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. [ABSTRACT FROM AUTHOR]

Liquid manipulation using tubular actuators finds diverse applications ranging from microfluidics, printing, liquid transfer to micro‐reactors. Achieving flexible and simple regulation of manipulated liquid droplets during transport is crucial for the tubular liquid actuators to perform complex and multiple functions, yet it remains challenging. Here, a facile tubular actuator for directional transport of various liquid droplets under the control of an externally applied magnetic field is presented. The surfaces of the actuator can be engineered with submillimeter‐sized through‐hole pores, which enables the liquid droplet to be easily modulated in the transport process. Furthermore, the liquid actuator with featured through‐hole pores is expanded to function as a switch in an integrated external electric circuit by magnetically controlling the motion of a conductive liquid droplet. This work develops a strategy for regulating liquid droplets in the tubular actuation systems, which may inspire ideas for designing functional liquid actuators with potential applications in microfluidics, microchemical reaction, liquid switch, and liquid robotics. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive structural‐color materials have received widespread attention in information encryption due to the significant color changes under different stimuli. However, the trade‐off between the capacity of information input, security level, cost, and large‐area manufacturing greatly limits the application of structural colors in encryption. Herein, dynamic high‐capacity and high‐resolution encryption are achieved by implementing printed total internal reflection (TIR) structural color and computer‐aided image recognition. The printed TIR microstructures are prepared with relative humidity (RH) responsive polymer, which form a heterogeneous wettability system, and can exhibit vibrant color variation with humidity. As the implemented RH is changed, the printed microstructures will expand or shrink precisely, enabling a full‐color modulation across the visible light range. With the color change, each structural‐color pixel can be specifically encoded, allowing for this to encrypt dynamic information within the same pattern at different RHs. Furthermore, This study can precisely integrates tremendous different pixels and easily prepare various encrypted patterns, which guarantee the high‐capacity information input in a low‐cost way. Moreover, through computer programming and algorithm reading, the structural‐color patterns can be decoded and decrypted in real‐time, thus offering great potential for further encryption, anti‐counterfeiting, multiplexing encoding, and data storage. [ABSTRACT FROM AUTHOR]