Futuristic container ship with air-trapping hull gliding effortlessly across the sea.

Water Walking Wonders: How Advanced Surfaces are Redefining Buoyancy and Drag Reduction

Mira Elwood in Tech & Innovation August 2025 • 4 min read.

"Dive into the innovative world of hybrid superhydrophobic surfaces and their revolutionary impact on marine technology, inspired by nature's own water striders."

For centuries, humans have been fascinated by the ability of certain creatures to effortlessly glide across water. Water striders, diving beetles, and lotus leaves each possess unique adaptations that allow them to interact with water in remarkable ways. Scientists have long sought to replicate these natural phenomena, and recent breakthroughs in surface technology are bringing us closer than ever to achieving similar feats.

A promising area of research involves creating superhydrophobic (SH) surfaces, which repel water. These surfaces have shown great potential for reducing hydrodynamic friction, a concept similar to microbubble drag reduction, where a layer of air is created between a solid surface and the water. The idea is that combining these two approaches could lead to significant advancements in marine vessel efficiency.

Imagine a ship that uses a carefully engineered surface to trap air, creating a lubricating layer that allows it to glide through the water with minimal resistance. This isn't just a theoretical concept; researchers are actively developing and testing materials that could make this a reality. This article explores the fascinating science behind these innovations, delving into the potential applications and the impact they could have on the future of maritime transport and underwater exploration.

The Science of Superhydrophobic Surfaces

Futuristic container ship with air-trapping hull gliding effortlessly across the sea.

Superhydrophobic surfaces achieve their water-repelling properties through a combination of surface texture and chemical composition. The goal is to minimize the contact area between the water and the solid surface, creating a layer of air that reduces friction. One method involves creating a hybrid SH/superhydrophilic (SHL) surface, where specific areas are designed to either repel or attract water. When submerged, the SHL areas encourage water contact, while the SH areas trap air, leading to a unique interaction between the solid, liquid, and air.

The key is to manipulate the behavior of air bubbles at the solid surface. Underwater, a SH/SHL surface evolves into a superaerophobic/superaerophilic (SAH/SAHL) surface. This means that the SHL areas repel air bubbles, while the SH areas attract and hold them. By carefully designing the patterns of SH and SHL regions, scientists can control the way air bubbles accumulate on the surface, leading to increased buoyancy and reduced drag. Several techniques exist for creating these patterned surfaces, including electrochemical etching, chemical methods, and laser texturing. Laser texturing, in particular, offers a precise, maskless, and chemical-free approach for creating highly controlled SH/SHL patterns.

Increased Buoyancy: SH surfaces trap air, increasing the overall buoyancy of the object.
Drag Reduction: The trapped air layer reduces friction between the object and the water.
Tunable Properties: SH/SHL patterns allow for precise control over air bubble distribution.
Versatile Applications: This technology can be applied to various marine vehicles and underwater devices.

The article highlights a study where aluminum alloy plates were treated with picosecond laser texturing and stearic acid to create SH surfaces. These surfaces were then selectively re-treated with a second laser pass to create SHL patterns. The researchers found that they could control the load-bearing capacity of the plates by altering the position and area of the SH surfaces. In one experiment, a 20 cm² plate was able to support a weight of 7.5g, which is 1.34 times its own weight. This outstanding weight loading capacity demonstrates the potential of this technology for creating buoyant and efficient marine vehicles.

Future Implications and Applications

The research discussed in this article represents a significant step forward in the development of advanced surface technologies for maritime applications. By mimicking nature's own solutions for water interaction, scientists are paving the way for more efficient and sustainable marine transport. The ability to tune the buoyancy and drag reduction properties of these surfaces opens up a wide range of possibilities, from reducing fuel consumption in cargo ships to enabling new types of underwater vehicles for exploration and research. As the technology continues to develop, we can expect to see even more innovative applications emerge, transforming the way we interact with the marine environment.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1021/acs.langmuir.8b02879, Alternate LINK

Title: Tunable Bubble Assembling On A Hybrid Superhydrophobic–Superhydrophilic Surface Fabricated By Selective Laser Texturing

Subject: Electrochemistry

Journal: Langmuir

Publisher: American Chemical Society (ACS)

Authors: Ke Sun, Huan Yang, Wei Xue, Menghui Cao, Kenneth Adeyemi, Yu Cao

Published: 2018-10-12

Everything You Need To Know

How do superhydrophobic surfaces achieve their water-repelling properties, and how does this compare to microbubble drag reduction?

Superhydrophobic (SH) surfaces repel water through a combination of surface texture and chemical composition, minimizing the contact area between the water and the solid surface. This creates a layer of air that reduces friction. A hybrid SH/superhydrophilic (SHL) surface is created, where SHL areas encourage water contact and SH areas trap air, leading to a unique interaction between the solid, liquid, and air. The effectiveness of superhydrophobic surfaces is measured by how well they reduce hydrodynamic friction. This reduction is similar to microbubble drag reduction, where a layer of air is created between a solid surface and the water. However, a key difference lies in the method: superhydrophobic surfaces use surface texture and chemistry to trap air, while microbubble drag reduction introduces air bubbles externally.

What are superaerophobic and superaerophilic surfaces, and how are they created from superhydrophobic and superhydrophilic surfaces for underwater applications?

Superaerophobic/superaerophilic (SAH/SAHL) surfaces are underwater evolutions of superhydrophobic/superhydrophilic (SH/SHL) surfaces. When a SH/SHL surface is submerged, the SHL areas repel air bubbles (becoming SAH), while the SH areas attract and hold them (becoming SAHL). By carefully designing the patterns of SH and SHL regions, scientists can control the way air bubbles accumulate on the surface. This control over air bubble accumulation leads to increased buoyancy and reduced drag for underwater objects. The strategic manipulation of SAH/SAHL properties enables the development of advanced underwater vehicles and devices with enhanced performance characteristics.

How is picosecond laser texturing used in the creation of superhydrophobic and superhydrophilic patterns, and why is it considered a precise method?

Picosecond laser texturing is used to create both superhydrophobic (SH) and superhydrophilic (SHL) patterns on surfaces. First, a surface, such as an aluminum alloy plate, is treated with picosecond laser texturing and stearic acid to create SH properties. Then, specific areas are selectively re-treated with a second laser pass to create SHL patterns. The precision of laser texturing allows for creating highly controlled SH/SHL patterns, enabling researchers to fine-tune the buoyancy and drag reduction properties of the surface. This maskless and chemical-free approach offers a versatile method for manufacturing advanced surface technologies.

In what ways can superhydrophobic surfaces enhance buoyancy and reduce drag, and what makes the use of SH/SHL patterns so advantageous?

By trapping air, superhydrophobic (SH) surfaces increase the overall buoyancy of an object, while the trapped air layer reduces friction between the object and the water, leading to significant drag reduction. SH/superhydrophilic (SHL) patterns allow for precise control over air bubble distribution, enabling tunable buoyancy and drag reduction properties. The ability to manipulate these properties makes SH and SHL surfaces attractive for various applications, including improving the efficiency of marine vehicles and enabling new underwater devices. For instance, controlling the load-bearing capacity by altering the position and area of the SH surfaces can significantly improve the performance of marine vehicles.

What are the potential future implications of superhydrophobic and superhydrophilic surface technologies for maritime transport and underwater exploration?

The development of superhydrophobic (SH) and superhydrophilic (SHL) surfaces, inspired by nature's water striders, is a significant advancement. By mimicking nature's solutions for water interaction, scientists are paving the way for more efficient and sustainable maritime transport. The ability to tune the buoyancy and drag reduction properties of these surfaces opens up possibilities such as reducing fuel consumption in cargo ships and enabling new types of underwater vehicles for exploration and research. The progress in this area will likely lead to even more innovative applications, transforming how we interact with the marine environment.