Theoretical and Experimental Studies of the Functional Structure Effect on Directional Transport in Biomicrofluidics

Surfaces in nature that are capable of directional transport of liquids by using their own microstructures have become a research focus in recent years. However, research on the directional transport function of biomicrostructures is still ongoing, and there is still a lack of quantitative studies on the functions of such biostructures so far. Based on the microstructural surface of Nepenthes, a systematic research study on the biomimetic microstructure surface is presented. In this study, the mechanism of the directional transport function is analyzed, and the functional structure effect on directional transport is investigated in detail. The realization of the transport function of the Nepenthes peristome is achieved by the unique surface microstructure and super-hydrophilic surface. The structures are modeled with simplified geometries, and the critical geometric parameters affecting the transportation function are identified. To verify the transportation function of the designed microstructure, orthogonal experiments are designed to explore the relationship between the liquid transport and the structural parameters. Experimental studies show that the transport speed of the liquid varies while the transportation function is achieved with the modeled structures. The velocity increases as the distance within the two microcavities increases and decreases as the width of the microcavity increases. The study is helpful for better understanding the mechanism of directional transportation by microstructures and provides optimum guidance for producing functional structures applied in biomicrofluidics.