Antony van Leeuwenhoek was bacteria’s first serious spectator. Squinting through a self-made microscope at a smudge of plaque scraped from his teeth, he dropped the curtain on the squirming organisms we know today as the world’s simplest and oldest life forms.

This Dutch blue-collar worker may have had little formal training in science, but his pursuit to magnify nature down to its finest grains was anything but microscopic. In the 17th century, Leeuwenhoek uncovered the minute world of blood cells, bacteria, and protozoa and made some of the most important findings in the history of biology.

Victoria Soghomonian remembers being struck at a very young age by Leeuwenhoek’s discoveries, instinctively painting in her mind microbial scenes from the pages of her science text. What did he think, she wondered, when he first laid eyes on the alive-and-kicking creatures that live beyond the realm of our finite vision?

Now an Ohio University physicist, Soghomonian wonders what it would be like for the microscope enthusiast to look through her eyes and view some of the most fundamental particles in the universe, structures thousands of times smaller than his sea of microbes. Surely he would be astounded to see her and others participating in a new kind of small-scale science, one that could turn out to be as profoundly huge as his own fundamental discoveries.

This science — or revolution in the making, some say — is nanotechnology, a young field that focuses on building new materials and devices on the infinitesimal scale of molecules and atoms. Ohio University physicists, engineers, and chemists are among a growing collection of scientists worldwide investigating these essential building blocks of matter with the goal of forever altering the way we manufacture electronics, treat disease, protect the environment, and secure information.

In a world visible only under powerful microscopes, nearly 20 researchers in the Ohio University Nanoscale and Quantum Phenomena Institute are exploring ways to make cleaner, stronger, and more precise materials from the bottom up, atom by atom, molecule by molecule. They also are deeply engaged in the debate about the futuristic vision of the nanoworld as being a place of infinite possibilities, promising us such incredible inventions as tiny machines that could be injected into our bodies to repair cancer cells and clothes made of mini-motors that would keep us cool when it’s hot and dry when it rains.

Some researchers say nanotechnology will transform our future; others say they can’t predict where this mostly theoretical science will take us. But there’s one point on which they all agree: Somehow, it’s going to be important.

From The Bottom Up

First, a lesson. The prefix nano comes from a Greek word meaning “dwarf.” In measurement terms, a nanometer represents one-billionth of a meter, or the size of 10 hydrogen atoms side by side. Because the nanoworld is so unimaginably teenytiny, it easily throws our normal sense of scale out of whack. For example, the period at the end of this sentence holds an astonishing 50 billion square nanometers. Nanoscale numbers are so large that it’s difficult to find anything remotely comparable in the universe, not grains of sand on a beach, not stars in a galaxy.

But don’t let size deceive. The molecules and atoms that live in the nanoworld are the bread and butter of all matter, something scientists have known for a long time. Way before modern atomic theory was formed in the early 1800s, the ancient Greeks speculated that matter was made up of particles in perpetual motion. Through the years, scientists went on to validate the existence of the atom and its proton, neutron, and electron components, as well as uncover the mysteries of radioactivity, quantum mechanics, nuclear physics, astrophysics, and many other aspects of our physical world.

Nanotechnology, however, is a novel science that completely changes the way we approach matter. It works by building structures from the bottom up, snapping together atoms and molecules to create entirely new materials and devices on the nanoscale. It’s not much different from what nature does at its most basic level. In the biological world, most of life’s processes — digestion, immunity, even thought — are carried out by molecular machines constructed of proteins. What nanotechnologists want to do is mimic nature’s system of self-assembly to improve on things we already have and make things that never have existed before.

“Nature builds it best. Essentially, we’re trying to imitate it on a very small scale,” says Soghomonian, who, with Jean Heremans — both assistant professors of physics and astronomy — is involved in nanoscience research at Ohio University.

Although atoms and molecules can be arranged one by one with the aid of elaborate equipment such as scanning tunneling and atomic force microscopes, self-assembly is a much faster, more efficient way to build structures on the atomic level, they say.

“One of the advantages of self-assembly is that you don’t actually have to pick up things one by one and put them where you want them, which is a very elaborate process,” Heremans says. “The technique of manually manipulating atoms is, however, useful for research.”

Soghomonian and Heremans are employing this spontaneous building technique to investigate ways of creating a quantum computer. It’s one the first nanotechnology projects funded on campus with the support of a four-year, $1.2 million grant from the National Science Foundation. The project is among many in the works in the university’s Nanoscale and Quantum Phenomena Institute, which was created in 2001.

A quantum computer, in theory, would look like a grain of salt from the outside, but on the inside would be capable of storing much more data than the average desktop computer. Such a computer, unlike those of today, would work not according to the digital logic we’re used to, but would rely on a completely different set of physics principles — those of quantum mechanics — to carry out a huge number of operations simultaneously. While Ohio University researchers won’t build an actual quantum computer by the end of their fouryear study, they’ll have a better understanding as to whether the idea could become a reality.

Soghomonian and Heremans believe that constructing a quantum computer’s architecture may involve using some of nature’s most basic materials. When you cook up ingredients such as salts, metals, and acids, nanoscale crystals with grid-like patterns take shape. These crystals, called zeolitic materials, contain millions of holes that researchers say could house singleelectron transistors that act something like transistors in today’s computer chips. Connected to these tiny transistors would be strands of DNA, “molecular wires” selected for their flexibility and ability to self-assemble.

Before any of this can be done, however, the researchers need to figure out how to make DNA an effective electronic conductor. They’ve been working with Ohio University forensic chemist Bruce McCord to discern how DNA sequence and the addition of enzymes, dyes, and metals to DNA molecules affect electronic conductivity.

“It turns out that DNA is not a good conductor at all, so we are trying to modify it to make it have some electronic properties,” says Heremans, whose DNA conductivity research recently was published in the journal Applied Physics Letters. “At this point, we’re taking voltage measurements with some promising results.”

As for how a quantum computer would actually function, two Ohio University physicists believe magnetism at the atomic level might be an answer. Transistors that run today’s electronic devices are based on the moving electric charges of electrons. Assistant Professor of Physics and Astronomy Arthur Smith and Research Associate Haiqiang Yang are examining how the magnetic “spin” of an electron could be exploited to power such devices as a quantum computer.

Although nanotechnology researchers take different approaches on how a quantum computer will move from idea to actuality, most believe it eventually will. When that time comes — whether it be decades or a half-century from now — its impact is expected to be profound. Besides storing massive amounts of data, scientists say, such a computer could be the ultimate code maker and breaker, a concept in which defense officials worldwide already are keenly interested.

“Nobody is anywhere close to having a quantum computer, but just a few years ago, I thought it was a pipe dream,” Heremans says. “It’s still very hard to predict when it may become reality, but the mere idea that it is possible is enough to spur research.”

In the meantime, their DNA conductivity research could have implications in other areas, including medicine. Scientists know, for example, that damaged DNA and cancer are linked, but they’ve yet to find a way to determine if, when, and where DNA damage has occurred. Researchers theorize that by measuring how a charge is transported through a DNA molecule, they may be able to determine whether it’s impaired or healthy.

What’s more, McCord is finding insight into his work that may impact the field of forensic science. When Soghomonian and Heremans add metal ions to DNA to improve its conductivity, they’re finding this altered DNA to be quite stable, retaining the metal indefinitely if left untreated. This prompted McCord to think about what makes DNA forensic samples so hard to purify once retrieved from a crime scene.

“We’re postulating that some of the problems we’re having in isolating DNA from older forensic samples might be the result of contamination from metals,” says McCord, an associate professor of chemistry and biochemistry. “If you think about it, metal ions are everywhere. For example, iron is found in our blood.”

Quantum computers may seem as far apart from cancer research and forensic science as humans are to the tiny nanoworld, but their fundamental connections embody the potential of nanotechnology to permeate many facets of our lives.

Quirky Quantum Mechanics

It’s hard to talk about nanotechnology without introducing quantum mechanics. It’s a layer of the nanoworld that pushes the envelope of physics and, like the atomic size scale, seems surreal compared to the world in which we live. Take gravity, a law of physics we encounter every moment of every day. Drop a glass, and we all know what will happen. Quantum mechanics, however, assumes a completely new set of rules in which classical physics don’t apply and gravity hardly matters. It is the physics of the small.

“When you get to the atomic scale, things start to behave completely differently. Everything is turned upside down,” says Savas Kaya, an Ohio University assistant professor of electrical engineering and computer science.

Kaya is familiar with the quirks of quantum mechanics because he is studying ways to progressively shrink transistors and other integrated circuit technology used in computers, TVs, radios, phones, cars, and other devices. He’s driving the transistor’s transition from micro to nano, the realm in which particles begin misbehaving.

Employing simulation tools to help him predict the effects of quantum mechanics, Kaya constructs computer models of transistors based on various factors, including type of material, atom distribution, geometric patterns, and strength of electric fields. His goal is to use his simulations as templates to guide the construction of nanoscale transistors that are immune to the physics of scaling down. He hopes to begin a new experimental project soon using the fine electron beam of a scanning electron microscope to study roughness patterns in nanoscale transistors and circuits.

Kaya isn’t alone in his pursuit to miniaturize devices that run everyday electronics. Researchers around the globe are fervently working in academic and private industry settings to make transistors as tiny as a few atoms across.

“There are a number of advantages to making circuits smaller,” says Kaya, whose work is supported through an Ohio University Baker Fund award and has been published in various journals. “You increase performance and speed because you reduce the distance that signals have to be sent. Also, manufacturing costs are lowered because for the same amount of effort, you can produce more and better devices.”

While Kaya is attempting to mitigate the effects of quantum mechanics on small-scale circuits, Ohio University chemist Greg Van Patten is exploiting the phenomena in a way that could improve the performance of lasers, computer monitors, and lights in our homes.

Individual nanoscale metal particles, particularly silver and gold, reflect and absorb light differently than when they are part of a bulk material, say in a coin or bar of gold. They also have focused electric fields that Van Patten believes can be enhanced by controlling the particles’ relationships to one another. Based on this theory, Van Patten is constructing molecule-thin, multilayered polymer films in which he plans to place metal particles in a distinct pattern that may enhance their light absorption efficiency.

“If we can control these spatial relationships, we could enhance the efficiency of lasers, computer monitors, and lights anywhere from 100- to 1,000-fold,” says Van Patten, an assistant professor of chemistry and biochemistry whose research has been funded through the U.S. Department of Defense. “Anything that emits light is potentially fair game.”

A Road To Better Medicine

Our body’s system of blood vessels is analogous to an interstate, complete with exits that channel into zip codes mapped from head to toe. Only certain cells, however, have access to certain off-ramps. Delving into the nanoscale world of proteins, Ohio University chemical engineer Doug Goetz and physicist David Tees are examining how these biological exits work and ways to set up roadblocks in specific locations to help relieve inflammatory diseases such as arthritis, lupus, diabetes, and asthma.

Under normal circumstances, white blood cells circulate the bloodstream waiting to be called by damaged tissue to sites of injury or infection. Our blood vessels contain a layer of cells with protein receptors that, when tissue damage has occurred, become sticky and snatch passing white blood cells. This Velcrolike mechanism provokes inflammation, the body’s normal response to tissue damage.

There are cases, however, when this healing process backfires. Most inflammatory diseases progressively worsen when white blood cells enter the picture because they cause an overactive inflammation response. Goetz and Tees want to block white blood cell activity in these cases by creating a drug with two components: chemistry that gives the drug the “sticking” capabilities of white blood cells and an anti-inflammatory treatment to slow down disease progression.

“In this way, we can make the drug go where we want it to go and shut down the ability of the vessel walls to make these sticky receptors so the white blood cells won’t interfere,” says Goetz, an associate professor of chemical engineering.

Based on their studies of the biochemical interaction between white blood cells and vessel walls, the researchers have developed particles that accumulate, like white blood cells, at areas of tissue damage. The next, and most difficult, step is to merge these particles with existing drugs that can block white blood cell adhesion. “We’ve shown that they work individually, but we’ll probably spend the next few years putting the pieces together,” Goetz says.

The researchers have received multiple external grants for their work, which has been published in several journals, including Blood, Biotechnology and Bioengineering, and Biophysical Journal. Nanotechnology is at the heart of their research because they’re mimicking the body’s natural process of drug delivery, which runs on complex protein interactions on the nanoscale, says Tees, an assistant professor of physics and astronomy.

“Nature has a soup of molecules swimming around, and they somehow manage to find each other and form incredibly complex structures,” he says. “Ultimately, we’re trying to figure out how these processes work so that we can imitate them to perform tasks that we want to accomplish.”

Slant Toward Science Fiction

Nanotechnology elicits the same “gee-whiz” factor that microbiology surely did when Antony van Leeuwenhoek first brought bacteria into focus.

“I clearly remember as a kid reading about this Dutch gentleman who hundreds of years ago found a whole zoo of stuff under his microscope lens,” Soghomonian recalls. “Can you imagine the impact it had on the world? We cannot predict the impact of what we are doing, but it’s sort of the same thing.”

Leeuwenhoek knew he’d stumbled onto something important, but he couldn’t fathom that his curious sightings would lead to such medical breakthroughs as the development of lifesaving vaccines and antibiotics and the emergence of new fields of study in genetics, physiology, and immunology.

Similarly, today’s scientists don’t know where nanotechnology research will lead them. On one hand, this fledgling science is portrayed by some visionaries as the panacea for the world’s problems. Molecular manufacturing will be so inexpensive, efficient, and pollutant-free, they say, that it will provide for everybody’s basic needs. Futurists see nanosubmarines traveling through our circulatory system cleaning arteries and destroying cancer cells, small filtration systems scrubbing toxins from the air and removing hazardous organisms from drinking water, and endless repositories of food cultivated not on farms but from atoms.

Ohio University researchers are optimistic about nanotech’s potential to improve the quality of our lives, but they say some predictions probably are exaggerated. Other nanotechnologists agree, including Princeton University Professor of Physics Robert Austin, who studies biological molecules and systems from a physics perspective.

“A lot of this stuff is science fiction,” Austin says. “There seems to be a lot of hype about the future. People need to realize that it’s harder to make these things than you would think. It’s a difficult technology. Right now, we’re at the point of learning how to make a few things, and they’re very primitive.”

It doesn’t help, either, when futurists, novelists, and mainstream media present a dark view of nanotechnology. Michael Crichton’s 2002 novel Prey, for example, tells the story of self-reproducing nanorobots that escape from a Silicon Valley laboratory and begin evolving into predators. Although some nanotechnologists do envision a day when molecular machines will be able to build perfect replicas of themselves, the science — if, in fact, it is possible at all — is light-years away.

“Of course, it is a work of fiction, but it still is misleading because the field is not sufficiently advanced to do this and may never be,” Heremans says of Crichton’s book.

Scientists don’t dismiss the danger, however, that nanotechnology could pose. Most agree it’s time to begin tackling the potential ethical issues of code-breaking quantum computers and even the notion of self-replicating nanobots. Ohio University nanoscience researchers and others across campus are becoming part of this discussion by initiating a project to survey members of the scientific community and general public about their perceptions of nanotechnology. The survey, which has generated strong interest at the National Science Foundation, is being conducted through the university’s Institute for Applied and Professional Ethics.

“We hope to find out what misconceptions are out there and what we need to do to educate people,” Soghomonian says. “Anytime you have technological progress, you always have some people who say that it’s the end of humanity. It’s like the public’s perception of nuclear energy when scientists started the Manhattan Project. Of course, nuclear energy is a part of our everyday lives now, for good and for bad, and people needed to be educated about the good parts and the bad parts.”

Much like the Manhattan Project, the quest to advance nanotechnology clearly has become a race among nations, including the United States, Japan, Australia, European countries, and others. As a result, scientists are pushing to apply what they know of this nascent technology to products we use today. Nanomaterials already exist in stain-resistant fabrics, cosmetics, sunscreens, and hair dyes. Manufacturers say tennis balls with a nanocomposite coating bounce twice as long, and similar nanomaterials are making bumpers and other automobile parts lighter, stronger, and dent-resistant.

This is just the tip, many researchers say, of a science that may become the distinctive technology of the 21st century.

“In historical times, people were discovering new continents, new places. People went to the moon in the 1960s,” Soghomonian reflects. “This is inner space. It’s a new frontier, and that’s what drives us to do research. We know the results will be very exciting.”

To learn more about Nanoscale and the Quantum Phenomena Institute, visit
http://nqpi.phy.ohiou.edu/