Using the Sun and Biology, a Solar Car Becomes More Efficient

Around 3.5 billion years ago, life emerged on Earth. While life during those early days would likely be barely recognizable when compared to the multitude of complex life forms that populate the planet today, life had begun.

While we typically see humans as the pinnacle of evolutionary development, other life forms have achieved remarkable evolutionary feats that have optimized their bodies, and by extension, their abilities to find a niche on our planet and thrive in what can often be a hostile environment.

Recently, at least in an evolutionary sense, researchers and engineers have taken notice of the success that different species on our planet have displayed, and they’ve started to develop algorithms that replicate this success by borrowing some of the planet's most successful morphological strategies. This process is called biomimetic engineering, or biomimicry.

According to Merriam-Webster, biomimicry is "the imitation of natural biological designs or processes in engineering or invention. "The dictionary also describes one of the first modern uses of biomimetic design: the invention of Velcro, which occurred when, in 1948, Georges de Mestral, a Swiss engineer, noticed how burs would stick to his dog's coat while walking outdoors. After examining the structure of the burs, Mestral created a synthetic bur that mimicked the form and function of the flora.

Like all cars on the road today, a solar car needs wheels. But unlike cars that are propelled by the awesome force of chemical potential energy, a solar car is fueled solely by the sun. Unfortunately, modern solar cells aren't as efficient as plants in transforming the sun's rays into energy, so engineers must make solar-powered cars as lightweight and efficient as possible if these vehicles are to gain speed and drive for a reasonable distance.

As you can imagine, optimized aerodynamics play a big role in making a solar car more efficient, but that's just one part of a multifaceted effort that’s needed to make a solar car go. Another critical aspect of a solar car’s design is lightweighting.

From the driver to the batteries that store the vehicle’s energy, everything about a solar car must be as lightweight as possible. And so, the students working on a solar car team are tasked with optimizing every component of their solar car in an effort to achieve greater speed and endurance. The job of redesigning the solar car's wheel was, Tian Hu Hao,—not an easy assignment when you think about it.

The wheel has been a staple technology for well over 5,000 years, and has been the method by which we drive vehicles (think chariots) for three millennia. Over the centuries, the wheel has been improved to the point that, today, we take for granted the sophisticated design of the rims and rubbers that keep our cars, buses, planes and other conveyances rolling down the road. Whether you need a disc for scooting across the moon, revving up rough terrain, or just coasting down the highway, there are wheel options to suit your needs. But because of their ubiquitous use, wheels can also be customized—and that's exactly what Hao set out to accomplish.

When you think of a modern wheel, you likely imagine a cylinder that's been milled to produce spokes that join at a central hub. These spokes come in all shapes and sizes and oftentimes emphasize styling over function. For Hao, inverting that notion was the key to his design process.

If function were to follow form, Hao wondered how far the spokes of a wheel could be trimmed down while still providing enough support for the wheel while it was stationary and used for driving. While traditional simulation regimes would have allowed Hao to simulate how a wheel’s design would work, he would have needed to iterate his design several times, trimming back and adding material based on the simulation results. That process would have taken far too much time. Instead, Hao turned to Altair Inspire, and used the software’s generative design tools to optimize his wheel design so that it could be a strong and lightweight as possible.

For Bob Little, president of Altair Canada, biomimicry "is seeing something in nature that evolved over time and asking yourself, why did it evolve into that form?" When his company introduced the world's first biologically inspired topology optimization software, Little had that very notion in mind. "When I see something in nature, evolution guided it for good reason, and I should take advantage of that in my design." Engineering student Tianhao Hu Hao seemed to agree.

Using the biomimetic simulation algorithms and parametric design tools built into Altair Inspire, Hu ran structural simulations on a basic, spokeless wheel design and constrained it to represent the forces that would be applied to the wheel used by the solar car. With his constraints in place, Inspire's topology optimization algorithms were set to work on designing the model.

The model that Hao was presented with after running his simulation was something remarkable. Not only was his solar wheel extremely light, it was also extremely strong. Add to that the fact that the wheel was as objectively beautiful as any mass market rim, and Hao knew he had a winning design.

Hao's reinvention of the wheel is an important example of what engineers can achieve today when their work is informed by biomimicry; however, it is only a part of the story that engineering has to tell about the wonders that can be found in evolutionary design.

Today, more than ever before, biomimetic design is informing a fledgling branch of design technology. While biomimetic algorithms for lightweighting and optimizing designs are available in many CAD packages, other examples of biologically inspired innovation are still being being developed.

In the future, algorithmic biomimetics could potentially enhance everything from robotic locomotion to phase-shifting materials and beyond. By harnessing the vast morphological material and locomotive resources stored away in our planet's evolutionary past, engineering innovation may reach new heights in efficiency and performance. What's more, by harnessing computing power and proven evolutionary strategies together, a new era of design might be upon us. With that in mind, it's worth pondering the statement once waxed by Carl Sagan, "What new wonders, undreamt of in our time, will we have wrought in an another generation and another."

For now, the answer remains open, but the possibilities are as vast as the depth of evolutionary time.

For more information on Altair's nature-inspired topology optimization software, visit the software website here.

Altair has sponsored this post. They have no editorial input to this post. Unless otherwise stated, all opinions are mine. —Kyle Maxey