Nav: Home

Fish, seaweed inspire slippery surfaces for ships

September 15, 2020

WASHINGTON, September 15, 2020 -- Long-distance cargo ships lose a significant amount of energy due to fluid friction. Looking to the drag reduction mechanisms employed by aquatic life can provide inspiration on how to improve efficiency.

Fish and seaweed secrete a layer of mucus to create a slippery surface, reducing their friction as they travel through water. A potential way to mimic this is by creating lubricant-infused surfaces covered with cavities. As the cavities are continuously filled with the lubricant, a layer is formed over the surface.

Though this method has previously been shown to work, reducing drag by up to 18%, the underlying physics is not fully understood. In the journal Physics of Fluids, from AIP Publishing, researchers from the Korea Advanced Institute of Science and Technology and Pohang University of Science and Technology conducted simulations of this process to help explain the effects.

The group looked at the average speed of a cargo ship with realistic material properties and simulated how it behaves under various lubrication setups. Specifically, they monitored the effects of the open area of the lubricant-filled cavities, as well as the thickness of the cavity lids.

They found that for larger open areas, the lubricant spreads more than it does with smaller open areas, leading to a slipperier surface. On the other hand, the lid thickness does not have much of an effect on the slip, though a thicker lid does create a thicker lubricant buildup layer.

"Our investigation of the hydrodynamics of a lubricant layer and how it results in drag reduction with a slippery surface in a basic configuration has provided significant insight into the benefits of a lubricant-infused surface," said Hyung Jin Sung, an author on the paper.

Now that they have worked on optimizing the lubricant secretion design, the authors hope it can be implemented in real-life marine vehicles.

"If the present design parameters are adopted, the drag reduction rate will increase significantly," Sung said.
The article, "A lubricant-infused slip surface for drag reduction," is authored by Seung Joong Kim, Hae Nyeok Kim, Sang Joon Lee, and Hyung Jin Sung. The article will appear in Physics of Fluids on September 15, 2020 (DOI: 10.1063/5.0018460). After that date, it can be accessed at


Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex or multiphase fluids. See

American Institute of Physics

Related Cavities Articles:

The presence of resonating cavities above sunspots has been confirmed
An international team of researchers, led by the Instituto de Astrofísica de Canarias (IAC), has confirmed the existence of resonant cavities above sunspots.
HIV alone not a risk factor for cavities in children
Recent studies indicate HIV infection heightens the risk of dental cavities - but a Rutgers researcher has found evidence that the risk of cavities comes not from HIV itself but from a weakened immune system, which could be caused by other diseases.
How the giant sequoia protects itself
A three-dimensional network of fibers makes the bark resistant to fire and rock fall.
Bacteria in Chinese pickles can prevent cavities -- Ben-Gurion University study
Prof. Ariel Kushmaro of the BGU Avram and Stella Goldstein-Goren Department of Biotechnology Engineering and the Chinese research team evaluated 14 different types of Sichuan pickles from southwest China.
Diabolical points in coupled active cavities with quantum emitters
Diabolical points (DPs) introduce ways to study topological phase and peculiar energy dispersion.
Tree cavities for wild honeybees
The forests in Europe provide habitat for around 80,000 colonies of wild honeybees.
Vapor drives a liquid-solid transition in a molecular system
The reversible switching of macrocyclic molecules between a liquid and a solid phase upon exposure to vapor has been reported in the Journal of the American Chemical Society by researchers at Kanazawa University.
Machine-learning research at OSU unlocking molecular cages' energy-saving potential
Nanosized cages may play a big role in reducing energy consumption in science and industry, and machine-learning research aims to accelerate the deployment of these remarkable molecules.
Understanding surface science to manufacture quality cosmetics
A team of researchers, affiliated with South Korea's Ulsan National Institute of Science and Technology (UNIST) has identified variables that control the cavity-filling rates, required for liquids to penetrate into the cavities.
Bio-inspired materials decrease drag for liquids
Tiny nature-inspired cavities that trap air can stop liquids from sticking to surfaces without the need for coatings.
More Cavities News and Cavities Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: IRL Online
Original broadcast date: March 20, 2020. Our online lives are now entirely interwoven with our real lives. But the laws that govern real life don't apply online. This hour, TED speakers explore rules to navigate this vast virtual space.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

There are so many ways to fall–in love, asleep, even flat on your face. This hour, Radiolab dives into stories of great falls.  We jump into a black hole, take a trip over Niagara Falls, upend some myths about falling cats, and plunge into our favorite songs about falling. Support Radiolab by becoming a member today at