The Lily Impeller: Nature-Based Design Inspires Game-Changing Efficiencies

This story is part of Treehugger's news archive. Learn more about our news archiving process or read our latest news.
The Lily Impeller (right) next to a nautilus shell. (Photo: Pax Water).

“I grew up on the beach in Australia,” says inventor Jay Harman. “I spent most of my time underwater trying to spear fish. I noticed that if I grabbed on to seaweeds to stabilize myself while swimming, they’d just break off in my hand. And yet they stay attached by themselves just fine – even in the wildest of storms. Even though the movement looks chaotic, they all change their shape to a particular pattern – a spiral formation. Those same spirals are literally everywhere in nature.”

This initial insight eventually led Harman to develop radical, energy-saving technologies which, he claims, may one day fundamentally change how humans do almost everything — from generating energy through purifying our water to cooling our homes.

The Ubiquitous Spiral

Jay Harman

Seashells, tornadoes, even the dirty water swirling out of your bathtub — the origins of the spiral’s dominance lie in a decidedly utilitarian fact:

“There is no such thing as a straight line in nature. All gases and liquids move in a spiral formation because that’s the path of least resistance. There’s virtually no drag. Because all living things go through a fluid phase in their development, we take on those shapes too. And yet human beings still insist on making things in a straight line.”

Harman (right), who was already building crude canoes for his fishing expeditions, began experimenting with curves and spiral shapes. He sketched his vision for a boat “as nature would have designed it,” and took it to a boat-building expert who told him that it couldn’t be done. Soon, Harman was proving him wrong, building these energy-efficient boats — dubbed the WildThing and the Goggleboat — and winning the Australian Design Award in the process.

But it was only when he turned his attention to the boats’ propellers that things got really interesting. Harman was convinced that the secret to more efficient propulsion was in the spiral patterns he had been seeing since he was a kid.

“What if we could reverse engineer a whirlpool, I thought, what if we could get the correct geometries? But no one could do that at the time. Because a vortex like that is constantly moving around, it becomes incredibly complicated to pin down. It took me twenty years to figure out how to freeze a whirlpool/ But when I did, it allowed us to see that all movement of fluids can be described with one algorithm with four variables.”

Harman’s discovery led him to develop the Lily Impeller, a spiral- or vortex-shaped propeller that moves water by mimicking the patterns it would naturally move in anyway.

Energy-Efficient Water Mixing

While it was originally conceived as a propeller for boats, Harman’s own company — Pax Water Technologies — brought the Impeller to market as a means for utilities to mix the water in their storage tanks.

“That impeller – which we barely changed from the frozen whirlpool shape we started with – now sits in over 500 water storage tanks around the world. This tiny little device – not more than 6 inches high – can circulate hundreds of millions of gallons of water for the same amount of energy it takes to light up a light bulb. Because the water isn’t stagnating, utilities are using 85 percent less disinfecting chemicals, and they’re mixing the water with 80 percent less energy than they would otherwise need.”

Improved Wind Turbines and Propellers

But mixing water is, says Harman, just one application for this spiral-shaped technology. As he explained in this video for FLYP Media back in 2009, the Lily Impeller is potentially the starting point for reinventing almost everything.

The potential list of applications for this technology is mind-boggling. One of Harman’s subsidiaries has a wind turbine operating in California that measures 150 feet in diameter and that is delivering extremely promising improvements in efficiencies. Harman is also in talks with companies to develop products ranging from hair dryers to refrigeration units and industrial mixers to a water purification system that could help tackle some of the major water quality issues associated with fracking for natural gas.

Nanotechnology Innovations  

As with any such innovation, it might be tempting to ask why it has not been developed before. The truth is, says Harman, we simply haven’t had the capabilities to deal with such complexities:

“If you look at the industrial revolution, people were only able to make flat, square or straight things. They weren’t worried about energy efficiency — if you wanted to go faster or harder, you simply added more fuel. With the advent of advanced computing, 3-D printing and other advanced manufacturing technologies, we finally have the power to build things as nature would.”

The advent of nanotechnology, which mimics the cell-by-cell, virtually waste-free production processes of nature, promises to take these capabilities to the next level.

A Fundamental Rethink of Everything 

Lily Impeller

Harman argues that the world is finally on the cusp of a new sustainable design revolution based on biomimicry and the patterns and processes of the natural world. He has compiled stories of such nature-based design from around the world, publishing them in his forthcoming book, "The Shark's Paintbrush: Biomimicry and How Nature is Inspiring Innovation." The Lily Impeller is, says Harman, just one part of a fundamental paradigm shift that we urgently need if we’re going to thrive as a species.

“Most of the energy we use is used to overcome friction. It’s perfectly possible for us to almost eliminate that friction using the same strategies that have evolved over millennia. And that’s just one example of how we can use the design power of nature to overcome the challenges we face.”