Monday, May 2, 2011
Advice From Nature
Researchers, Students Borrow Ideas from Plants and Animals
You can’t fool Mother Nature, but you can learn from her.
CMU researchers and students have found inspiration from her for a variety of projects. The process, called biomimicry, is an innovative method that seeks sustainable solutions by emulating nature’s patterns and strategies.
From product design to computer science, flora and fauna have served as templates for solving problems in unexpected ways. Here’s a few of them.
Dale Clifford, an assistant professor of architecture, looks to nature for patterns and processes that might be applicable to other areas.
“Nature is the single and most complex system that has been field tested the longest,” Clifford said. “The relationship of process, material deposition and pattern formation is really interesting, and there are forces of nature that we haven’t tapped into at all in the construction industry.
“Nature makes everything largely at room temperature, largely with soft and pliant materials. We usually do the opposite. We heat things up, beat them to submission and exert a lot of energy to get things to function well. But in nature, there is a direct correlation of construction, form and performance,” Clifford said.
While working for a company called Molecular Geodesics, Clifford studied the skeleton of a cholla cactus.
“I studied the patterning, and made a physical model,” he said. “Because of the way the model was constructed, it had different properties than the cactus skeleton, with flexible joints, it could transform to a small bundle, advance to a maximum volume then fold into a plane.”
With his team, he transferred the patterning of the cholla, to the design of improved surgical retractors and more resilient spinal implants.
“It was a very collaborative environment,” Clifford said. “Biologists, physicists, chemical engineers, computer scientists, people with diverse viewpoints that got together to solve problems. That started my interest in biological structures as they related to design and not just architecture.”
At CMU, Clifford teaches a course each fall titled Bio_Logic, a workshop-based course in which students transfer knowledge from the domain of biology
to the field of design.
“Last semester students looked at the operative principles behind flocking in birds and swarming in bees and then studied the simple rules of logic that govern change across entire systems,” Clifford said. “Our goal is to apply the interactivity inherent in nature to design strategies for a more environmentally responsive and regenerative built environment.”
In an experimental forms class, Mark Baskinger works with students who have backgrounds in industrial design and product development. Through the course, students investigate open-ended problems based on principles of movement.
“Much of the inspiration that they use at the onset of the project comes from nature,” Baskinger said. “It’s sort of a bionics model for us; we look at natural phenomenon, structures, movements, mechanisms, growth patterns, both for structure and composition as well as aesthetics.”
One of the course projects is to make chess pieces that have moveable parts.
“The mechanisms are inspired by, say, a grasshopper’s leg or how a beetle’s shell opens, very simple mechanisms,” he said. “The chess set is fun; this is the second time we’ve done it. The students like it because it’s defined already, they are somewhat familiar with it and they
can really experiment with the form.
Now with this new wrinkle of moving components and pieces parts, it actually allows them to use computer modeling in a very advanced way, in ways that they may have not before.”
A serendipitous moment opened Ziv Bar-Joseph’s eyes to the idea of studying fruit flies.
While listening to a student describe how cells in flies make decisions, the mechanisms being used sounded very similar to a computation problem for the associate professor of machine learning and computational biology.
“The flies solution actually worked under more strict conditions than any method previously known in computer science,” Bar-Joseph said. “They were able to solve it under much more extreme conditions and were very accurate.”
Based on the way the flies determine cell fate in their brains, a team of scientists from Israel and Carnegie Mellon created a new method to effectively deploy wireless sensor networks and other distributed computing applications.
“Computational and mathematical models have long been used by scientists to analyze biological systems,” Bar-Joseph said. “Here we’ve reversed the strategy, studying a biological system to solve a long-standing computer science problem.”
The cells in the fly’s developing nervous system manage to organize themselves so that a small number of cells serve as leaders that provide direct connections with every other nerve cell.
The result is the same sort of scheme used to manage the distributed computer networks that perform such everyday tasks as searching the Web or controlling an airplane in flight. But the method used by the fly’s nervous system to organize itself is much simpler and more robust than anything humans have concocted.
“Engineers are very good at solving specific problems and solving it efficiently. Biology is not always just about efficiency, but it is about robustness and handling different environments,” Bar-Joseph said.
Metin Sitti has been using his work with geckos to inspire a new method to print electronics on complex surfaces. He and other researchers developed a reversible adhesion method for printing electronics on a cache of sticky surfaces, such as clothing, plastics and leather.
“This work gives us the opportunity to transfer and print electronics on complex surfaces,” said Sitti, director of the Nanorobotics Lab. “The team designed a square polymer stamp with pyramid micro-tips that allows them to control adhesion strength.”
Like the geckos, which are wizards at sticking to any kind of surface, the new polymer stamp also features a distinct adhesive quality. Key to the square polymer stamp is four pyramid-shaped micro-tips on the stamp’s bottom. They mimic the micro- and nano-hairs on the gecko’s foot, which the animal uses to control adhesion by increasing or decreasing their contact surface area.
“This is a breakthrough in the way we will be able to bundle complex electronics to a variety of industry sectors,” Sitti said.
For more than a decade, Sitti has been designing and fabricating gecko-inspired fibrillar structures as new repeatable adhesives. He founded nanoGriptech LLC in 2009 to commercialize these new materials for sports, medical devices, robotics, defense and space applications.
“There is really no limit to what the gecko-adhesives and nature teach us as we continue to explore new opportunities,” he said.
Industrial design student Linda Dong spun an old idea on its head when she created an award-winning chair.
“I started off with a problem of how do we make chairs that can be easily put together by the user or could easily be flatpacked, such as what IKEA does,” Dong said.
“I looked at lightweight structures and situations where animals create or manufacture their own products, and that’s when I came upon spider webs. They’re really resilient but lightweight filaments that spiders weave themselves to create a structurally sound object.”
Dong, who is minoring in biology, created a product that involved a frame and strong string. Consumers can wrap the string around the frame in any desired pattern. Using only tension from the string, the piece can hold its structure easily without additional glue or fastners.
Her design won the AskNature.org 2010 Earth Award Student Design Sketch Competition.
“Just by looking at the way nature fixes its own problems, we can apply that to problems of our own and figure out that the solution is right there,” Dong said. “That’s basically the fundamental philosophy behind biomimicry, which is what I’m looking to kind of integrate into design. You see a lot of it in engineering: trains based off the beak of a bird, or the wind generators based on the whale fins,” Dong said. “When you mix disciplines, that’s where creativity really lies.
“The best things come out of biomimicry. I never see it come out worse than we come up with before. It’s always better. It never creates a less-optimal
solution. It’s pretty cool.”
By: Heidi Opdyke, firstname.lastname@example.org