Different from tuning wettability, our group has recently developed a fluid diode fabric solely made from hydrophilic materials ( 12). In both cases, liquid tends to transport from lyophobic (e.g., hydrophobic or oleophobic) side to the lyophilic (e.g., hydrophilic or oleophilic) side of the material before the lyophilic side is saturated but is blocked in the reverse direction. Such materials were achieved by differential treatment of wettability or lyophilicity across the fabric thickness or combining multilayers of materials with different wettability or lyophilicity as an asymmetric construct ( 10, 11). Recently, porous materials (e.g., fabrics) allowing transient directional liquid transport have been reported. In addition to functional clothing, this concept can be extended for developing materials for oil-water separation, wound dressing, geotechnical engineering, flexible microfluidics, and fuel cell membranes.ĭirectional liquid flow phenomena are widely found in nature on insects and plants including beetle’s back ( 6, 7), spider silk ( 8), and cactus branch ( 9), where one-way water collection is driven by the heterogeneous geometry and gradient wettability.

The permeability, mechanical property, and abrasion resistance (up to 10,000 cycles) of the fabric were not affected by the treatment. The flow directionality is explained by the Gibbs pinning criterion. This exceptional property is achieved by creating gradient wettability channels across a predominantly superhydrophobic substrate. The water transmission rate can be 15 times greater than that of best commercial breathable fabrics. Here, we demonstrate a “skin-like” directional liquid transport fabric, which enables continuous one-way liquid flow through spatially distributed channels acting like “sweating glands” yet repels external liquid contaminants. Personal moisture management fabrics that facilitate sweat transport away from the skin are highly desirable for wearer’s comfort and performance.

Test breathability liquid