In 1959, the physicist Richard Feynman (known for safecracking at Los Alamos, bongo playing, and his insights into quantum electrodynamics) gave a talk at Caltech entitled, “There’s Plenty of Room at the Bottom.” That prophetic lecture is often cited as the beginning of nanoscience, the study of matter at the scale of one billionth of a meter. At Nanowerk, I found a video, Kavli Foundation: An Introduction to Nanoscience, in which narrator Alan Alda explains how Feynman’s seminal thoughts were sparked by his interest in cellular biology. Feynman figured nature had been in the nanotechnology business for billions of years, and eventually we would be too. Through the trial and error of evolution, life has engineered some remarkable devices, such as the bacterium’s spinning motor that it uses for propulsion, and the ultra-fine, spatula-shaped hairs that allow a gecko’s foot to stick to glass.
Before getting to other general sites on the nanoworld, let’s start with the gecko, which has become, in the nano-age, the poster child for “bioinspiration.” Humans have always looked to nature to get ideas for building tomorrow’s machines, but the process, also called “biomimetics,” is particularly useful in the world of the very small. Three TED lectures by biologist
Robert Full at the University of California at Berkeley offer a wonderful look into how biologists and engineers have worked together to reproduce the gecko’s remarkable climbing abilities. The first lecture is on animal movement. In the next, Full discusses evolution and engineering. The third, and most recent, is unexpectedly titled “Learning from the Gecko’s Tail”—that fifth appendage turns out to be equally important to the gecko’s motion in a number of surprising ways. But the animal’s feet remain its most impressive feature. Depending on the species, they come in many sizes shapes and colors: check out the images at Kellar Autumn’s Lab at Lewis and Clark College in Portland, Oregon. For an article on a carbon-nanotube-based glue inspired by the gecko’s foot, see Nanotechnology Mimics Nature’s Adhesive.
The butterfly’s wing is another major source of inspiration for nanotechnologists. The colors on the insects’ wings are produced by nano-scale structures instead of pigments, so researchers are interested in copying them, replacing today’s pigments that may be toxic or costly. See Butterflies Provide Clues for Replacing Color Pigments with Photonic Nanocrystals. For another article on the special optical properties of butterfly wings (and peacock feathers) go to Peacock Feathers and Butterfly Wings Inspire Bio-templated Nanotechnology Materials. The blueprint for minute sensors may also be hidden in the scales of the butterfly wing. Go to GE Scientists Discover that Nanostructures on the Surface of Butterfly Wings Exhibit Acute Chemical Sensing Capabilities to read about researchers who discovered that the nanostructures on scales have just the right high-performance optical properties to make extremely sensitive vapor detectors. The butterfly’s wing is also evolved to be extraordinarily dirt and water repellant. Go to Butterfly Wing Trick Could Make Self-Cleaning Windows a Reality to read about French research that may lead to crystal-clear windows. And finally there is the light emitting Diode (LED). Although engineers recently developed this miracle of modern lighting, researchers at the University of Exeter in England have found that LEDs Work Like Butterflies’ Wings. Apparently, the fluorescent patches on the wings of African swallowtails function just like LEDs, and they evolved the ability some 30 million years ago.
Spiders are another goldmine of inspiration for the nanotechnologists, from the minute hairs on their feet (see this news article) to the stronger-than-steel silk used in their webs. And the applications are often unexpected. See Spider Silk Delivers Finest Optical Fibres. Arachnids may help bring about the tiny, fast connections that make computers with optical circuits practical.
Not surprisingly, single cells, bacteria, and viruses may teach us the most about the nanoworld. To take a tour of this alien landscape—a surreal place where molecules dominate—visit the TED lectures and watch David Bolinsky Animates a Cell. The speaker, who created the movie for Harvard University’s BioVisions, describes the cell “as a hugely complicated city occupied by micromachines.” The full eight-minute version of the animation can be found here. Paul W.K. Rothemund, a “synthetic biologist” at Caltech, gives two more TED lectures describing how he fashions DNA molecules into nanostructures, what he calls DNA origami. Be sure to watch the second one (“Paul Rothemund Details DNA Folding”), which shows how he created hundreds of tiny “smiley faces” from DNA. It’s all a matter of computation. Within one of Rothemund’s lectures, I spotted a remarkable illustration showing the basic parts cells use, all undoubtedly useful components for future nanodevices. To peruse the off-the-shelf molecular parts that nature developed hundreds of millions of years ago, see molecular biologist and artist David S. Goodsell’s home page at the Scripps Research Institute in La Jolla, California. Scroll down to his poster “Molecular Machinery: A Tour of the Protein Data Bank,” which may be downloaded. Be sure to check his other scientific illustrations, wonderfully stylized glimpses into the nanoworld.
To see how the machines move on a larger scale see Cell Locomotion at the University of Edinburgh, in Scotland. And go to this article at ScienceMatters@Berkeley Nanoscience Imitating Nature, to read about the work nanoscientist Matthew Francis is doing using organic chemistry to assemble tiny devices inspired by viruses. He, like many others in the field, hopes the work will lead to such breakthroughs as new cancer treatments or highly efficient solar cells.
Educational sites with general information on nanoscience are not hard to find. The Exploratorium in San Francisco has Small Talk podcasts, which cover a number of topics in nanoscience. University of California Television, produced in San Diego, has a show for younger students called When Things Get Small, and other programs.
Exploring the Nanoworld, a site from the University of Wisconsin-Madison Materials Research Science and Engineering Center, explores the science and engineering concepts at a college level. The site for IN-VSEE, which stands for Interactive Nano-Visualization in Science and Engineering Education, is maintained at Arizona State University. Click on the menu bar to see their educational offerings, which range from learning modules to a gallery with animations. See, for instance Does Size Matter? to learn how the importance of different physical forces change from one scale to another. At the smallest scales of the nanoworld, quantum effects must be taken into account. (See Quantum Biology: The Spooky NanoWorld of Molecules.) Building small requires a different way of thinking. Take a peek at the technical aspects in this Nature magazine article: Making Molecular Machines Work.
But the nano-revolution that seems inevitable (there are already more than a thousand consumer products with nano particles of one sort or another) also carries risks. Take carbon nanotubes, for instance. They figure in many designs for future materials and devices, yet the fine tubes, may mimic asbestos in their danger to our health. An article in the Proceedings of the National Academy of Sciences, The Sackler Colloquium on Promises and Perils in Nanotechnology for Medicine gives a good technical account of how asbestos fibers damage cells and were really the first nano-hazard to be recognized. At the Web site of OnEarth, an independent publication of the Natural Resources Defense Council Defense, there is podcast, The Promise (and Perils) of Nanotechnology, on the state of government oversight of the emerging technology. Mentioned in the podcast is The Project on Emerging Nanotechologies, which was established in 2005, as a partnership between the Woodrow Wilson International Center for Scholars and the Pew Charitable Trusts, to track the powerful new nanotechnologies as they evolve—for good and bad.