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nano-nano
From Golf Balls to Fuel Cells, the Promise of Nanotechnology Isn't From Out of This World, But Some Place Better -- Pittsburgh!

Like a modern day Renaissance naturalist revealing a newfound secret of nature, PPG’s Head Scientist, Dr. David Diehl, held a tightly sealed jar between his outstretched thumb and forefinger. The vessel was filled halfway with five-nanometer magnesium carbonate particles, the active ingredient in some popular antacids. It looked like a jar of confectioner’s sugar until he tipped it back and forth gently, whereupon the mass sloshed up and down the sides of the container like a glass of milk. When he shook the vessel, smoky bubbles percolated through the top of the settling particles, forming a white cloud that hung above the surface. When asked why the white particles were visible, he responded, “We don’t know for sure. You shouldn’t be able to see them individually because each particle is much smaller than any wavelength of visible light. And you can see that they’re not agglomerated, because they wouldn’t flow the way they do if they were stuck to each other. My best explanation is that weak molecular interactions, called van der Waals forces, pull the particles close enough together to scatter light.”


Van der Waals forces are just one of numerous physical phenomena that become more evident as particles become smaller and behave more like atoms and molecules than bulk materials. As he put the still-smoky container back into his desk drawer, Dr. Diehl continued, “The difference with nano is in the approach to doing things. Nano is more like what nature does in building things from the ground up, rather than from the top down, as we have done in the past. Traditionally, we have taken a piece of bulk material and milled it down into a product. With nano, we build things atom by atom, molecule by molecule. So there’s a basic difference in the approach. We’ve seen some surprises. And we expect to see more as this technology develops.” If surprising phenomena can be taken as a measure of scientific opportunity, nanotechnology’s cup is overflowing. And as a world-renowned, center of science, scholarship and industry, so may Pittsburgh’s.


The question is how to get nano-enabled products out of the laboratory and into the world. In response to that question, the recently formed Pennsylvania NanoMaterials Commercialization Center promises to provide a lynchpin between pure nanoscience and the marketplace. Championed by United States Congressman, Mike Doyle, founded under the auspices of the Pittsburgh Technology Council, the “consortium,” as it is commonly known, is designed to leverage the intellectual horsepower of western Pennsylvania’s renowned universities, Carnegie Mellon, Penn State and the University of Pittsburgh, with the market savvy of the Steel City’s manufacturing giants, Alcoa, Bayer, PPG and U.S. Steel.


As Congressman Doyle put it, “The real challenge is to get nanotechnology into a form that can benefit us today. Sometimes these research projects that we spend hundreds of millions of dollars on never get to market because the economics don’t allow companies to make that final step. The nanotechnology center is designed to bridge that gap and bring products to market.”


Earlier this year, in his opening address at the Pennsylvania Business of Nanotechnology Conference, Dr. Doros Platika, CEO of the Pittsburgh Life Sciences Greenhouse, said, “Nanotechnology is both nothing new and a new frontier.” He went on to explain that our recent ability to measure and see nano events has opened a world of cross-disciplinary science in which things work differently than in the “bulk” world. Because nanotechnology concerns itself with phenomena at the bottom of matter, distinctions between scientific disciplines tend to blur at nanoscale. In the field of physics, protons, neutrons and electrons interact to form atoms; in chemistry atoms interact to form molecules; in biology molecules interact to form living cells. This unavoidable convergence of scientific disciplines gives rise to a need for scientists who, while expert in one field, are sufficiently fluent in their sister sciences to communicate across disciplinary boundaries. It is perhaps a stroke of irony that today, while interdisciplinary teams have supplanted the lonesome geniuses of Renaissance lore, cross-disciplinary fluency has re-emerged as the customary way of life for nanoscientists everywhere. Although nanotechnology is projected to have a life cycle measured in decades, its evolutionary effects are being felt now, in the form of such products as high- performance tennis rackets, flame-retardant computer disks, self-cleaning windows, soil-resistant khakis and solid-oxide fuel cells. In the future, nanotechnology holds revolutionary promise for virtually every field of human endeavor, from slice-resistant golf balls and chameleon-color surface finishes to highly sensitive, non-invasive medical diagnostics, precisely targeted drug delivery and, ultimately, health care customized to each of our DNA profiles. By definition, nanoscale objects are mind-bogglingly small: A nanometer is one billionth of a meter. One-ten-thousandth the diameter of a human hair. The National Science Foundation puts nano at between one nanometer and one hundred nanometers in one dimension: bigger than an atom; smaller than a cell. To put nanoscale into perspective, starting at the bottom and rounding the numbers to keep the arithmetic from morphing into mathematics: It takes about 10 atoms lined up side-by-side to add up to one nanometer in length. As such, the average diameter of a molecule can be thought of as one nanometer. In his doctoral thesis, Albert Einstein calculated the size of a sugar molecule to be one nanometer. A single DNA molecule is about two nanometers wide. Nuclear pores, the holes in nuclei walls that permit communication with the rest of the cell, are about 10 nanometers wide. The nucleus itself is about 250 nanometers across. A red blood cell, about 2,500. One drop of blood contains about 5 million red blood cells or, put another way, just under 4 quadrillion molecules. That’s more than all the stars in the Milky Way; less than all the stars in the universe. Admittedly, such explanations bring new meaning to such previously insignificant phrases as “really, really small.” Despite the recent vogue surrounding nanotechnology, nanoscale objects have been around forever. They occur in both natural and synthetic states. Naturally occurring nanotubes made of halloysite clay are mined by the ton in Utah. Nano-sized structures called bucky balls are found in the carbon black that gives newspaper ink its color. The red in medieval stained glass windows comes from the use of gold nano particles in the glass.


In the more recent past, according to Todd Osman, Ph.D., Technical Manager for United States Steel, the company has been looking at and manipulating nanostructures in its products since the 1950s. Today, as important as nanostructure may be to product properties such as strength and ductility, Osman says that nano-enabled process sensing and control devices are equally important, because they enable heretofore- unachievable levels of precision control during manufacture.


When asked to elaborate upon nanotechnology’s value to Bayer, Dr. Robert Kumpf, Vice President of Future Business at Bayer MaterialScience replied, “A lot of physical properties come about from the surface of a material rather than the bulk of the material. One of the incredible leveraging aspects of nanotechnology is that, when you go down in size, the surface area increases geometrically in proportion to weight, so you can have the same weight of material with a tremendous gain in surface area.”


The difference between yesterday’s natural and coincidental occurrences of nano materials and today’s burgeoning new field of nanoscience, is that today, we can detect, see and manipulate nanoscale objects and events. That capability is the result of progressive improvements in the field of microscopy over the past several decades. “Without tunneling microscopes, nanotechnology would not be possible,” Dr. Platika said. “Because, if you can’t see what you have when you manipulate a nano object, you can never know how to reproduce it again and again.”


Tunneling microscopes are one of a variety of instruments, collectively called scanning probe microscopes, which measure numerous phenomena between the instrument’s exquisitely small tip or probe and the surface of the object it is measuring. In order to maintain the integrity of objects under investigation, in most cases, the probe never actually touches the surface. Just as you can feel the heat of a fire without putting your hand in it, these high-resolution instruments detect forces without touching the surface. Because conventional optics cannot resolve nanoparticles, other properties such as topographic, thermal, electrical, magnetic, photometric and chemical characteristics are measured and rendered into visual representations of things otherwise invisible, at magnifying powers of more than one billion times.


Keith Blakely, CEO of Nano Dynamics, a Buffalo, New York nano-enabled materials company that recently opened a bio-nano materials laboratory in Pittsburgh, attributes nanotechnology’s rapid surge in development to the influx of high-power computer capability over the past decade or so. “High-resolution microscopes require computers that can process massive amounts of data and transform it into images,” Blakely said. “Today we can model, manufacture, measure and confirm with greater speed and reliability than ever before.”


Ironically, the profusion of computer capability to which Blakely refers has led to a profusion of information, which has created a need for smaller and more powerful logic and storage devices. Professor Ed Schlesinger, Head of Carnegie Mellon’s Electrical and Computer Engineering department, sees nanotechnology as an essential part of any solution to that problem. Dr. Schlesinger and his colleagues have recently put together a team to create a vision for moving beyond the scaling paradigm of CMOS (complementary metal oxide semiconductor). CMOS is the most basic physical/electrical principal upon which virtually all computers work today. While CMOS has served as the personal computer processing standard for several decades, it is limited by Moore’s Law, which says that computing power doubles every 18 months. So far Moore’s Law has proved true. However, scientists predict that limitations in the materials used to make integrated circuits will bring the age of Moore’s Law and CMOS to a close in the not very distant future.


“There is no question that Moore’s Law will come to an end,” Professor Schlesinger said. “Our vision for addressing that problem essentially involves the merging of Micro Electrical Mechanical Systems (MEMS) with integrated circuit technology in a kind of chip that we call a Memory Intensive, Self-Configuring Integrated Circuit. This chip will actually be able, with its own mechanical elements, to change itself physically to perform different functions. This vision is enabled by the ability to manipulate materials on the chip at the nanoscale.”


At Penn State’s Materials Science Institute, Dr. Paul Weiss and his colleagues are hard at work on the fundamental materials and processes necessary to achieve such capabilities. The Weiss Group has developed a chemical process for putting down lines as narrow as 10 nanometers wide, by means of a technology called “molecular rulers.” In principle, molecular rulers employ the extreme dimensional precision inherent in specific molecules to create templates for applying high precision lines of numerous materials, both conductive and non-conductive, to a variety of substrates. In other projects the group has explored the viability of single molecule switches for nano-electronics and tethering molecules to nanoscale substrates for possible use in nanosensors and other applications.


Presupposing future success in the development of devices and systems, such as those described above, CMU Professors Seth Goldstein and Todd Mowry are working on the development of software algorithms for a future nano-enabled communication medium called “Claytronics.” Claytronics will use ensembles of millions or perhaps billions of micro-scale devices called catoms to self-assemble into replicas of distant objects, such as you or me, or the chairs in which we might be sitting, through a media transmission protocol called telepario. Claytronics would make it possible for your doctor to examine you in your home, while working from his office. In theory, your replicated self, called an avatar, would self- assemble out of a pile of catoms in your doctor’s office while his avatar would do the same in your home. Sensors on each avatar would transmit configuration and response data to the other end of a line, much the way telephone calls, faxes, e-mails and cable signals do in present times. While Professor Goldstein says that the details of how this system will actually function are obscured by a great deal of future investigation, he says that the development of such hardware capabilities is inevitable. As Professor Goldstein sees it, nanotechnology is essential to the development of Claytronics technology due to its requisite inexpensive, high-density electronics, as well as for purposes of achieving realistic appearance and motion in self-assembled objects. “We will have to borrow ideas from nature to get this to work,” Goldstein says. “The adhesion mechanism that we are thinking about right now is a biomimetic material based on the feet of a gecko.” Gecko lizards are able to climb vertical and horizontal surfaces as a result of billions of nano-hairs on the bottom of their feet. Each hair is roughly 200 nanometers in diameter. Between the aggregate surface area of all those hairs, their ability to conform at nanoscale to surfaces of virtually any texture and (here we go again), van der Waals forces, the animal is able to cling without expending any internal energy. The energy used to cling to a surface comes from the weak molecular forces at play between the gecko’s nano hairs and the surface’s nano structure.


Although scientists have demonstrated the ability to “pick and place” objects as small as atoms since 1989, today many nanotech thought leaders defer to Mother Nature as nanotechnology’s repository of methods, formulary of recipes and designer of systems. “Natural biological systems figured out nanotechnology millions of years ago,” said Dr. Alan J. Russell, Director of the University of Pittsburgh’s McGowan Institute for Regenerative Medicine. “Everything bio is nano, because nanoscale entities influence cells and tissue,” he said.


As part of the McGowan Institute’s work, which ranges broadly across the biological sciences, one of Dr. Russell’s projects centers on the chemical synthesis of nanotubes that are able to sense biological agents, change color in their presence, and kill them by disrupting their cell membranes. Dr. Russell’s nanotubes have an impressive set of materials characteristics, including: a uniform inside diameter of 35 nanometers with 27 nanometer-thick walls. Tube length varies by a mean of about 1 micron, or one millionth of a meter. As though asking nanoscale precision to tip its hat to the bulk world, the tubes have been dubbed “nanomacaroni.” To date, Dr. Russell’s group has developed a straightforward, inexpensive, chemical method of molecular self-assembly for the nanotubes, with process yields approaching 100 percent. In addition, they have developed a process to make the tubes stand on end and self-assemble into clusters of three or four to create upright pillars measuring about 100 nanometers in diameter that affix themselves to a 120-nanometer-thick substrate to form “nanocarpet” for use in the biosecurity industry.


While much of nano-space appears to be occupied by large organizations, Pittsburgh Technology Council President and CEO, Steve Zylstra is quick to point out that a number of entrepreneurial companies are playing important roles in nanotechnology in the Pittsburgh region. Plextronics has developed a conductive polymer, using nanotechnology that promises to create a paradigm shift in lighting. Crystalplex develops and commercializes nanotechnology reagents for biomedical testing. Thar Technologies develops nano-enabled supercritical fluid technology. Nano Dynamics has taken nanotechnology to the device level, selling products as varied as high- forgiveness golf balls and solid-state fuel cells.


Returning to the question of how to turn nanoscience into nanocommerce, Dr. Luis Fanor Vega, Manager of Alcoa’s Engineered Finishes Division, explained, “The Pennsylvania Nano Materials Commercialization Center is different from other nanotechnology centers where they are trying to develop science and technology. We are trying to drive science and technology efforts from across the country and around the world and guide them toward application, manufacturing and commercialization.” Assessing the likelihood of Pittsburgh’s succeeding as a world leader in nano-space, Dr. Doros Platika said in a recent interview, “All the pieces are here. Pittsburgh is a very can-do community with a very strong base that cuts across biologics, engineering, computer science and materials science.” It sounds like a perfect place for a Nano Renaissance.


This article first appeared as a TEQ cover story.

© Copyright 2009, Thomas P. Imerito / dba Science Communications


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©2009 Science Communications
thomas@science-communications.com