A PFAS-free coating could help protect aircraft, wind turbines, and power lines from hazardous ice buildup.

Nature has mastered the art of repelling water, and scientists have long mimicked these strategies in manmade materials. But frost and freezing rain can quickly undermine even highly water-repellent surfaces.

To tackle this problem, researchers at Simon Fraser University integrated water and ice repellency into a single coating material by combining two strategies found in nature. Their approach could help shield airplanes, wind turbines, power lines, and other outdoor infrastructure from potentially dangerous ice buildup — a major advantage in colder climates.

“We wanted to explore whether combining the roughness-driven hydrophobicity of lotus leaves with the slippery behavior of pitcher plants could create a surface with enhanced performance,” says Hua-Zhong Yu, a chemistry professor at Simon Fraser University, who led the study.

“Lotus leaves stay dry because of their tiny micro- and nanostructures that trap air and prevent water from spreading, while pitcher plants use a thin, slippery, liquid layer that causes water, and even insects, to slide off easily.”

The slippery problem  

Historically, combining those two strategies into a single material has proven difficult. The tiny bumps and ridges lining the lotus leaf’s surface trap pockets of air beneath water droplets, minimizing contact with the surface and causing droplets to roll away. But those same structures can become a liability in icy conditions.

“Surface roughness can trap air and make a surface superhydrophobic but, once water freezes, that same roughness can actually give ice more places to grip onto the surface,” explains Sanpreet Kaur, a co-author of the study.   

Some icephobic coatings rely on slippery liquid layers known as slippery liquid-infused porous surfaces, or SLIPS, which reduce how strongly ice adheres. But these coatings often suffer from poor durability because the lubricating liquid can gradually wear away or wash off during exposure to the elements, such as wind and rain.

To address this challenge, the researchers developed a new class of SLIPS based on polydimethylsiloxane (PDMS), a flexible silicone polymer commonly used in everything from medical devices to sealants. To create the coating’s microscopic texture, they first treated polycarbonate sheets with acetone, forming rough crystalline patterns that served as molds.

They then infused the PDMS with silicone oil and cast it against the textured template, producing a hierarchically structured surface with both nano- and microscale features.  

Finding the sweet spot

The amount of oil turned out to be critical in balancing water and ice repellency.

“If too little oil is used, the surface does not become slippery enough to effectively reduce ice adhesion,” Yu says. “But if too much oil is added, the oil can ‘pool’ and cover the microstructures that are responsible for trapping air and maintaining superhydrophobicity.” 

The researchers found that roughly 30% oil content was the sweet spot. The resulting surface featured a water contact angle exceeding 171 degrees—meaning water droplets formed nearly perfect spheres—while maintaining extremely low ice adhesion. 

The coating also demonstrated self-cleaning behavior reminiscent of lotus leaves. In laboratory tests, water droplets rolled across the surface of sand-covered SLIPS, carrying the sand away and leaving behind a clean surface. This self-cleaning ability could help preserve the material’s long-term performance.   

Equally important, the lubricant remained relatively stable over time. Unlike many existing SLIPS materials, the textured micro- and nanostructures helped retain the oil within the coating rather than allowing it to separate or leak out. 

The coating formulation also avoids PFAS, fluorinated chemicals that can persist in the environment and pose health concerns. Unlike electrically heated de-icing systems commonly used on aircraft, the coating requires no external energy input.

“Our approach is passive, which means it’s designed to reduce ice adhesion through surface engineering rather than melting ice directly,” says Kaur.

Although the concept is appealing from environmental and economic perspectives, further testing is still needed. “The work is still at an early stage, and more long-term durability and environmental testing would be needed before practical implementation,” Yu notes.

Scaling up the manufacturing process remains a challenge, but Yu says the fabrication method itself is relatively simple and adaptable. “At small scales, these structures are easy to control, but reproducing the same roughness and lubricant distribution uniformly across larger surfaces becomes much more difficult.”

For now, the study highlights how combining multiple strategies found in nature—rather than mimicking a single organism—may help researchers solve longstanding engineering problems.

Reference: Cliff L. W. Ng et al., Combining the Pitcher and Lotus Plant: Supericephobic and Superhydrophobic Silicone Films. Advanced Science (2026), DOI: 10.1002/ advs.202520538.

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