By Daniel Schemer, October 2008
It’s difficult to fathom weaving a biological fabric around a mechanical form without steeping into the realm of science fiction. As much as technology has advanced within the last several decades, we’re still far, far away from the visions presented to us in countless books, television shows, and movies. Most of us have come to realize that all those literary and theatrical revelations from our childhoods have evolved into pipe dreams for adulthood.
Regardless of these personal gripes, it’s refreshing to know that we’re closer than we think when it comes to the merging of biological and mechanical operations. Developments in less visible scientific areas are heading for breakthroughs that can and will revolutionize the industrial world. Biomimicry has been gaining considerable momentum over the last few years due to its innovative philosophy: look to nature for the answers. “You just try and figure out what the problem is, and then try to determine where there’s a biological example of something like this being solved. That is a biomimetic approach,” explained Paul Calvert, Associate Dean for Research & Graduate Studies, Professor for the Material & Textiles Department, and Co-Director of the Biomedical Engineering Program.
The best definition of biomimicry is studying nature and reproducing its designs and processes to create sustainable solutions to human problems. According to the Biomimicry Institute, the core idea is that “Nature, imaginative by necessity, has already solved many of the problems we are grappling.” Biomimetics tries to reengineer the human, industrialized world to be more like the natural world. “In materials, we now see the aim as building into machines the same kind of toughness and flexibility we see in animals. There are obvious applications of this philosophy to sustainable engineering in general. We do not necessarily want cars that can eat other cars, but digestible cars might be a good idea,” said Dr. Calvert.
Paul Calvert’s interest in biomimicry began when he started working with synthetic ceramics and looked at the toughness of seashells and teeth as a method for improving durability. Experiments on littleneck clam, conch and nacre (aka mother of pearl) shells have shown there are thin interfaces between layers, which makes them very strong. It then becomes a question of how to apply this layer-building process to designing ceramics.
A more unique concept is research on the possibility of using bone composites to make cars and other vehicles. “If we knew how to make bone into that shape, at a reasonable price, it would be much better then metal,” said Dr. Calvert. Bones are comprised of, among other things, multiple layers of calcium phosphate and collagen matrix; this makes the substance not only lighter then steel, but just as tough and stiff. Since all biological material consists of composites, biomimetic material involves examining the different combinations of components in order to produce synthetics with superior properties. “Everyone can grow the formula in their own bones, but we can’t seem to grow them in a lab.”
A primary study for Dr. Calvert is nano inkjet printing and its biomimetic capabilities. This entails using biomimetic material as “ink” to form solid, layered shapes and objects. This has recently started to include electrical and mechanical components. In addition to producing printed electronics and various types of sensors, inkjet printing can also be utilized for tissue engineering using DNA and protein complexes.
Numerous studies are being done all over the world in the biomimicry field. Blue mussels attach themselves to rocks with their own adhesive; so, how can we mimic this underwater glue? Leaves are being studied to determine how they capture energy in the hopes of developing a molecular-sized solar cell. Starfish legs have tiny lenses that are able to channel light; scientists are looking to see how this photosynthetic material can be applied to optical lens-crafting. The silk from spider webs has been studied in an effort to create better elastic material. The composite layers of beetles’ shells are being studied to see if we can improve airplane flight. The spiral-shapes of shells and horns are often used for designing more efficient fan blades and propellers. Humpback whales have incredible dexterity when they swim due to the design of their flippers, which have bumps for maintaining their control of turns and sharp changes in direction. Studies are being done with this flipper design to determine the aerodynamic advantages, as well better efficiency for wind turbines. Early warning systems for Tsunamis have been developed using dolphins’ multi-frequency approach for emitting sound waves over great distances underwater. These examples are only a few of the many studies and capabilities going on in the field of biomimetics.
Like many scientific concepts, there are problems in the way of bringing biomimicry to the forefront of industrialization. One issue is that while substances like metal, glass, and plastic are easy to recycle, complex composite materials are more difficult and require chemical decomposition. “In a way, a dead animal recycles just fine. It decays and goes through molecular breakdown by other species. So we need to see how to recycle this material through answers in biology,” said Dr. Calvert. Another issue is that applying biomimetic principles would mean less mass production of products. “If we do the biomimetic thing, we would be making things slowly, one by one. Can we imagine moving from mass production to more localized steps?” As further development goes on in this science, setbacks like these will be addressed and solved.
With six patents and articles in over 235 publications, Dr. Paul Calvert has received worldwide recognition for his works in biomimetics, materials science, polymer science, inkjet printing, and soft electronics engineering. He holds a Ph.D in Materials Engineering from the Massachusetts Institute for Technology and a BA in Natural and Materials Science from Cambridge University in the United Kingdom. For more information on biomimetics, go to biomimicryinstitute.org or to Dr. Calverts’s profile.