Micropatterned Surfaces with Unidirectional Wetting Properties for Liquid Transport

Interest in micropatterned surfaces with unidirectional wetting properties has grown significantly due to their unique ability to enable controlled liquid manipulation. This property is essential for diverse applications, including microfluidics, water harvesting, and self‐cleaning systems, where directional droplet motion promotes efficient removal of contaminants and reduces surface fouling. Despite extensive research on anisotropic wetting, a comprehensive framework encompassing design considerations, fabrication methods, and practical challenges for unidirectional liquid transport remains underdeveloped. This review paper addresses this gap by presenting a holistic overview of micropatterned anisotropic surfaces and their wetting behaviors in unidirectional fluid handling. Key mechanisms of liquid transport, ranging from passive modes such as gravity and wettability gradient to active modes involving external stimuli, are discussed. This review critically evaluates surface fabrication techniques, highlighting their advantages and limitations. By critically analyzing recent advances and identifying key structure–function relationships, this review offers design principles and emerging fabrication strategies that can accelerate the development of next‐generation micropatterned surfaces for directional liquid transport in microfluidics, diagnostics, and surface engineering.