Creative people looking to nature for inspiration is not a new concept: writers Henry David Thoreau and Ralph Waldo Emerson are considered literary classics because they did it. For engineers and scientists, examining and emulating nature is just as seasoned a concept.

Looking back through history, there are plenty of examples of nature-inspired designs, such as those flying machines, or Velcro — the fabric fastener invented by Swiss engineer George De Mestral in 1948 was inspired by clingy cocklebur seeds. Barbed wire was modeled after the thorny Osage orange tree.

However, it wasn't until recently, in the last 30 years, nature-inspired designs garnered notable attention and, it could be argued, instated a truly radical change in engineering and science. In fact, such observations have become the foundation of an increasingly popular scientific field.

Aerospace engineer Theodore Von Karman perhaps said it best: Scientists discover the world that exists; engineers create the world that never was. Science is about discovering the natural. Engineering is applying math and science to create the artificial.

"Anytime a new research field emerges, it takes a while to put the basic building blocks together. It's just a matter of time. We're getting there," said S.K. Gupta, a mechanical engineering professor at the University of Maryland who teaches a bio-inspired robotics course, in recent Associated Press reportage.

Of note, this spring, biologists and engineers at Georgia Institute of Technology pulled off the first conference dedicated to bio-inspired design research in an array of disciplines, Slate (slideshow) reports just this morning.

Claus Mattheck of the Karlsruhe Research Center in Germany, for one, is helping to develop stronger bridges and supports by examining how tree trunks cope with massive loads overhead. He is one of many.

Recently, the world has seen a few popular successes, including cleaning products and paints that capture how some plants prevent water from sticking to leafy surfaces, effectively repelling dirt and contaminants.

IMT recently reported that General Electric (GE) researchers are looking at how the lotus plant self-cleans to produce everything from easy-to-clean building materials and cheap diagnostic devices with plastic microfluidic channels to self-cleaning cars and a ketchup bottle whose contents flow freely.

Meanwhile, Ken Sandhage, an engineer by training who studies materials at the Georgia Institute of Technology, has bred diatoms — single-celled algae with hard, silica-based shells — to apply to engineering problems. He grew a range of different types, each with a distinctive skeletal shape and each one-quarter the width of a human hair.

"Every species is capable of making a silicon cell wall with patterned features that are amazingly intricate — fine pores, ridges and channels," he told AP. "From an engineering perspective, that's spectacular."

Explains AP:

Diatoms are versatile as industrial building blocks because they can transform into a wide range of shapes. Sandhage envisions using barium titanate diatoms because they glow when doped with the element europium. Nesting such diatoms together could result in brighter LCD screens. Production, he said, would be relatively cheap, because the organisms take care of most of the precision work themselves.

Sandhage's initial introduction to diatoms gleaned an immediate reaction: the possibility of modeling nano-devices after the tiny algae.

There's also Anita Roth-Nebelsick, who studies materials at the University of Tübingen in Germany and who is working with the nearly invisible pores on the undersides of leaves. She, in a joint bionics project with ITV Denkendorf (Institute of Textile Technology and Process Engineering), has been developing textiles that automatically adapt wicking ability (i.e., drawing moisture away) to the climate surrounding the wearer.

Roth-Nebelsick has created a material that consists of two porous layers of synthetic fiber that sandwich a layer of chitosan, an organic, sugar-like substance, reports Wired. When the material is relatively dry, the pores in the synthetic fiber layers bind to each other, locking in remaining moisture. If it gets wet, the chitosan swells, pushing the fiber layers further apart and allowing evaporation.

Jay Harman, a naturalist turned inventor, has studied how natural systems minimize resistance or drag. By reducing drag, species like kelp avoid wasting energy.

Reports Slate:

Using recently honed computer models, Harman and his colleagues began to simulate the fluid dynamics of natural, low-resistance systems and to apply their findings to industrial design.

A refrigerator fan developed by Harman's company, PAX Scientific, experiences substantially less air resistance than a typical fan. As a result, it increases energy efficiency by 25 percent while generating an essentially identical airstream, according to Harman. The fan will become commercially available later this year.

As well, Deane Harder and his team at Germany's University of Freiburg are designing textiles inspired by stems of horsetails (vascular plants) that will form the basis of tough, lightweight structures such as airplane wing struts, reports Wired.

"The advantage is that you have these hundreds of thousands of (biological) systems," Harder said, "and you know they work because of evolution."

Indeed, scientists in the field of biologically inspired design argue that engineers can learn much from the world's most rigorous process: evolution.

"It really captures the imagination to show how much better organisms are at doing things," Marc Weissburg, co-director of Georgia Tech's Center for Biologically Inspired Design, told AP. "The natural world doesn't waste energy, accumulate a large amount of toxins or produce more materials than it uses."

German scientist Rolf Muller, who teaches at China's Shandong University, says his investigation of bat ears could improve sonar technology.

And Hang Lu, a Georgia Tech professor in chemical and biomolecular engineering, is looking to common worms to learn how to develop sensors that can one day distinguish smell. Eventually, she told AP, the technology could be used to track plumes of smoke from miles away and determine what is burning.

In fact, as a Christian Science Monitor article noted in December, we should care about insects "because human life depends more and more on engineering systems that must solve similar problems to function efficiently," according to Francis Ratnieks of the University of Sheffield in England.

Pharaoh ant foragers' efficient movement to and from a food supply exemplifies how "natural selection has made insect societies good at solving a problem that is simple to state but hard to solve," Ratnieks said in the journal Nature. The problem frequently confronts designers of traffic flow, electronic messaging, electricity transmission and other network systems, Christian Science Monitor pointed out.

As well, honey bees and bumble bees' flapping flight "carries aerodynamics into a region where conventional theory fails." (Bees actually are flying insects closely related to ants.) These bees have actually evolved a flight system different from that of most small flying insects: while some insects swing their wings in large arcs in order to fly, the bees' wings move in significantly shorter arcs while flapping at a relatively high frequency. This short-arc high-speed wing motion gives the bees a much wider power range than other insects enjoy. This knowledge may be advantageous in advancing the field of aerodynamics.

Designing and engineering a new technology or model from anew is both admirable and unquestionably hard (not to mention time-consuming). Fortunately, there already exists a blueprint for engineers and scientists' use — and it surrounds us all.

Sources

Gimme Nature
by Amanda Schaffer
Slate, July 18, 2006

Engineers Make Like a Tree
by Elizabeth Svoboda
Wired, July 10, 2006

Scientists look to nature for lessons
by Greg Bluestein
The Associated Press, June 25, 2006

Nature teaches engineers new tricks
by Robert C. Cowen
Christian Science Monitor, Dec. 1, 2005

Earlier: Insects, Cabbage Can Teach Engineers
Engineering on a Wing and a Prayer

Wings: Out of the Box
Virginia Tech-DARPA paper

Additional

Engineering nature
by Bruce Lieberman
Copley News Service, July 7, 2006