Superhydrophobic surfaces: Fundamentals, manufacture, and applications

Inspired by the “lotus effect,” superhydrophobic surfaces have been engineered to repel water with unparalleled efficiency.1 More specifically, low adhesion superhydrophobic surfaces, defined by a large water contact angle and low contact angle hysteresis, ease self-removal of liquids and particles from the surface through droplet rolling, jumping, or bouncing, thereby holding great prospects for diverse applications such as anti-icing, anti-fogging, self-cleaning, heat transfer enhancement, liquid manipulation, and energy harvesting2,3 In addition, the better understanding of superhydrophobicity has led to the development of new liquid repellency concepts such as superoleophobic surfaces,4 liquid marbles,5 or lubricant infused surfaces.6–8 In recent decades, the demand for liquid repellent properties has seen a marked increase, involving materials science, physics, device design, applications, etc.9,10 For example, multifunctional superhydrophobic surfaces integrating synergies of photothermal materials, phase change materials, structural, and chemical patterned wettability, etc., possess great potential in the fields of anti-icing and deicing. Additionally, droplet manipulation techniques are evolving for biochemical analysis and materials synthesis, among others. The development of superhydrophobic surfaces, alongside novel insight into droplet behavior mechanisms, and manipulation strategies of droplets on these surfaces are poised to widen their future applicability.