Airplanes might soon fly a little greener thanks to an idea borrowed from sharks. An Australian startup has created a thin plastic film with tiny grooves that mimic shark skin, which helps the animals move efficiently through water. When applied to aircraft, this film can reduce drag, cut fuel use, and lower carbon emissions—all without redesigning the planes themselves.

Developed by MicroTau, the material mimics the dermal denticles that let sharks glide effortlessly through water. When applied to aircraft, these patterns reduce aerodynamic drag.

“We can get 4 percent or even slightly more at cruise conditions,” a MicroTau spokesperson told New Scientist, referring to fuel savings. It’s a modest-sounding number but multiply it by the roughly 100,000 daily flights happening across the world and the impact is truly massive. In aviation, where every percentage point counts, a 4 percent efficiency boost could mean saving billions in fuel and thousands of tons of carbon. Taylor Swift liked this post.

A High-Stakes Bet on Nature’s Design

Henry Bilinsky, a physics-trained lawyer turned entrepreneur, founded MicroTau after winning a U.S. Air Force innovation challenge in 2015. The military wanted to reduce its massive $10 billion annual fuel bill. Bilinsky offered his solution: use UV light to etch shark skin patterns onto aircraft film.

“I proposed modifying a computer chip manufacturing method… and frankly, didn’t expect to hear anything back,” he told Bloomberg Green. But the pitch worked. Soon, Bilinsky was demonstrating prototypes at Wright-Patterson Air Force Base, and by 2016, MicroTau was born.

Since then, the film—essentially high-tech shrink wrap—has been applied to everything from Lockheed Martin’s hulking C-130J transport planes to Boom Supersonic’s sleek XB-1 prototype. The patches even held fast at Mach 1.18, over 1,400 km/h. “The patches survived these conditions comfortably with no observable degradation,” said a Boom Supersonic spokesperson.

The technology, called riblet film, reduces what’s known as skin friction drag. In turbulent flow, air forms microscopic whirlpools—“hairpin vortices”—that scrub an aircraft’s surface. But riblets, shaped just narrower than these vortices, keep them from forming near the plane. The result is less resistance and more efficient flight.

“We reliably get an 8% friction drag saving,” Bilinsky explained. “But on a typical aircraft, you’ve got half of your drag being friction drag, so that 8% becomes a 4% net efficiency gain. So 4% less fuel burned, 4% less carbon emissions.”

The Plane Add-On

What makes the technology especially appealing is its simplicity. Instead of overhauling engines or designing new aircraft, riblet films can be applied like stickers, similar to decals already used for airline logos.

“This makes it an extremely practical ‘add-on’ approach,” said Mahmoud Hussein, an aerospace engineer at the University of Colorado Boulder. No need for structural redesigns. No lengthy plane grounding.

And that practicality matters, because the world isn’t replacing its aircraft fleet anytime soon. “There’s $1 trillion of planes flying today which aren’t going to be thrown away,” Bilinsky noted. “Burning about $200 billion worth of fuel and producing a billion tons of carbon.”

In that context, riblet film isn’t just clever—it’s strategic and in more ways than one.

Delta Air Lines agrees. Through its Sustainable Skies Lab, the airline is testing the film on widebody Boeing 767s and narrowbody 737s. “This product is an example of an innovation that can be applied in the short-term,” Sangita Sharma, the Lab’s director, told FlightGlobal. She noted that even partial coverage of an aircraft could bring real benefits, depending on airflow and operating conditions.

Australian low-cost carrier Jetstar and the U.S. Air Force are also onboard, along with other commercial and military customers. The U.S. military has already completed four of six test flights, aiming to optimize aging aircraft with modern efficiency tweaks. “This ability to optimise our legacy airframes is allowing us to potentially save millions of dollars in fuel costs,” said Roberto Guerrero of the Air Force.

Scaling Up, Peering Ahead

At its lab near Sydney, MicroTau uses ultraviolet light to grow the film’s riblets layer by layer. “You run your finger across and you’ll hear that buzzing,” Bilinsky said, demonstrating the grooves that to the eye seem like nothing at all.

Backed by the Australian government and the Clean Energy Finance Corporation, MicroTau has raised over $8 million to expand production. A kilometer of film has already been made for upcoming flight trials. The company plans to scale up in Australia, then move into North America and Europe.

Yet Bilinsky isn’t stopping at planes. “We’ll also be having them in the water, in marine applications,” he said. Cargo ships are next in line for drag reduction. Anywhere things move through fluid, riblets could be applied.

But for now, aviation remains the front line. With electric and hydrogen-powered aircraft still on the distant horizon, existing technologies must shoulder the burden. Riblet films could help bridge the gap—cutting emissions today while we wait for the aircraft of tomorrow.