Small Wonder

Nanotechnology is on the verge of changing everything -- from cancer treatment to water desalination.

by / March 23, 2007
It's Sunday around 8 a.m. A regular guy in a typical neighborhood wakes up gently as the bedroom walls -- or more specifically, the wall paint -- change from a deep blue to a pleasant lemon yellow.

The previous night's festivities have taken their toll, so as he goes to pour himself a cup of coffee, he grabs a small device that resembles a blood-glucose meter. He feeds the machine a blood sample and connects it to the USB port on his computer, which immediately presents a report on his current health.

As the man's pounding head foretold, his blood-alcohol level hovers around 0.05 percent. He also finds his body is creating antibodies to fight off a cold virus. And, as always, he checks to see if his cancer is still in remission -- which it is.

If nanotechnology research blossoms the way its advocates promise, such a scenario may be only a few years away, and 2017 might make 2007 look like a technological stone age. Researchers teeter on the edge of breakthroughs that could change virtually every aspect of our existence. Nanotechnology -- complicated, fascinating and essentially invisible -- is poised to make the frontiers of imagination become everyday realities.

Weird Science
So what exactly is nanotechnology? The term refers to the engineering of materials at remarkably small sizes. One nanometer is one-billionth of a meter, and things that fit on the "nanoscale" include anything smaller than 100 nanometers. For comparison, a human hair is about 75,000 nanometers wide.

John Miller, vice president of business development at Pasadena, Calif.-based Arrowhead Research, is an authority on nanotechnology and co-author of The Handbook of Nanotechnology: Business, Policy, and Intellectual Property Law.

On the nanoscale, regular elements behave in highly irregular ways, Miller said, which leads to intriguing and useful possibilities.

Take gold, for example. Everyone is familiar with its properties at the macro scale. But nanoparticles of gold look and act completely different. Vanga Reddy, who finished his Ph.D. thesis in 2006 at the University of Bern in Switzerland, noted in his paper Gold Nanoparticles: Synthesis and Applications that gold nanoparticles show colors like ruby red, blue, green and orange, depending on the size and shape. The gold nanoparticles, he wrote, also show remarkable catalytic activity, whereas bulk gold is known to be catalytically inert.

Things at the macro or micro scale have certain properties, and you can do specific, known things with them, Miller said. "When you work with them at the nanoscale, they have whole new properties because there are quantum effects. You get whole new materials and you make completely new devices."

By far the most celebrated example of such unusual behavior was found in the element carbon, one of the most abundant elements in the universe. Diamonds, graphite -- even people -- wouldn't exist without carbon. But deep inside its structure, at the atomic scale, the material held a secret first discovered in the 1950s -- the carbon nanotube.

A carbon nanotube is a cylinder one nanometer in diameter made of either individual carbon atom sheets or multiple sheet layers "rolled" into seamless tubes. Two Russian scientists found larger 50-nanometer nanotubes in 1952. Although their work was published, it was largely ignored and eventually forgotten. In 1985, these carbon structures were again observed, only this time as spheres. Then in 1991, the cylinders -- or tubes -- were rediscovered. Since then, research into nanotechnology has grown exponentially.

When carbon atoms are arranged in this cylindrical structure, they become the strongest materials that will ever be made, Miller said. "These materials are stronger than anything anyone thought possible."

Indeed, carbon nanotubes can be hundreds of times stronger than steel at one-tenth the weight. The manufacturing implications alone are difficult to comprehend. But not only are they incredibly strong and lightweight, carbon nanotubes also are perhaps the most conductive material ever discovered. Some estimates suggest properly configured carbon nanotubes might be 1,000 times more conductive than copper.

If that weren't enough, numerous researchers are convinced that carbon nanotubes one day will be used to target the delivery of drugs used to treat various illnesses -- including the extraordinary process of seeking and destroying cancer cells.

Only the Beginning
Although Miller is excited about the possibilities of nanotechnology, he urged a tempering of expectations. "You can do this amazing stuff, but it's really complicated and we're just at the beginning," he said. "We are now where electronics probably was 50, 60 years ago. Scaling up to mass production at the right cost is no easy task. So far, no one has really been able to come to market with nanotubes that are cheap and work well."

Currently there are two established processes for manufacturing carbon nanotubes, but neither can cost-effectively produce large amounts of the material.

One method involves growing nanotubes through chemical reaction. Called "arc discharge," this method requires the heating of certain gases to a point where two carbon electrodes discharge an electrical arc. This arc reacts with the gas vapors, causing nanotubes to self-assemble.

The second process for creating nanotubes, known as "laser ablation," is akin to ultra high-tech whittling, and involves using high-powered laser lithography tools to reduce large chunks of carbon down to nanotubes. These lithography tools currently are used to etch integrated circuits on semiconductors.

Private venture capital is pouring into firms, which continue working on these and other methods that may result in the mass production of carbon nanotubes at an agreeable market price. Lux Research, a technology-consulting firm, produced a widely circulated report called The Lux Report that analyzed just how much is being invested in nanotechnology.

According to the report, from 1995 to 2006, approximately $3.08 billion was invested in 171 nanotechnology companies worldwide. Electronics and IT garnered the most investment in 2006, followed closely by health care, life sciences and manufacturing.

The federal government already has awakened to the possibilities. In 2001, the National Nanotechnology Initiative was launched to start coordinating government funding and research of nanotechnology. Indeed, nanotechnology has at least as much appeal to the government -- be it NASA, the National Science Foundation, the U.S. Department of Defense or any number of other agencies -- as it does to the private sector.

"The government has been investing in nanotechnology research formally since around 2000," said Celia Merzbacher, assistant director of technology research and development at the U.S. Office of Science and Technology Policy. "Our approach has been to sort of, as they say, let a thousand flowers bloom, to be very broad in the range and types of research that are funded."

Like Miller, Merzbacher said medicine and electronics generate a lot of excitement, but she too is cautiously optimistic about nanotechnology's future. The nanotechnology buzz is spreading and tends to generate exaggerated expectations.

"When people say there should be a grand challenge, nanotechnology is not really ready for that," Merzbacher said. "Those kinds of grand challenges are usually more of an engineering challenge once the science is known. We're not there yet. We're still learning a lot about nanotechnology and what happens at the nanoscale."

But given what is known -- and what is being developed -- it is easy to get caught up in the tide of nanotech anticipation. What follows is a look at four extraordinary ways nanotechnology is being applied, from practical applications to downright science fiction.

Stuff of Life
Water is one of our most basic and fundamentally important elements. Like carbon, none of us would exist without it. Yet most of the water on Earth is very nearly poisonous if ingested. For decades, scientists and engineers have struggled to create an efficient process to strip water of impurities -- making dirty water clean and seawater fresh.

The most common way to desalinize water today is by reverse osmosis, which is, very simply, forcing a solution through a filter to remove undesirable particles. In reverse osmosis desalinization, seawater or wastewater is forced through a membrane filter, which collects pure water on one side while trapping impurities -- like salt and bacteria -- on the other side.

The trouble with desalinizing water is it requires a lot of energy, usually more energy than the resulting water is worth. The solution has been to try to build an ever more efficient system, and specifically, a more efficient membrane.

That's where nanotechnology and Erik Hoek come in.

Hoek, assistant professor at the University of California, Los Angeles, Henry Samueli School of Engineering and Applied Science, developed a nano-engineered membrane that could potentially slash the cost of desalination.

"As the water moves from the feed side of the membrane, right up to the membrane and passes through it, it brings with it everything else that's in the water -- salt, bacteria, organics," Hoek explained. "And all that stuff, because it doesn't pass through the membrane, a lot of sticks to the membrane. It's like any kind of filter. It eventually gets clogged. You've got to clean it out somehow. So the two [aspects] you can really try to target are the resistance by the membrane and the fouling layer build-up -- how quickly the membrane gets clogged."

Hoek said the key to building a better membrane was studying the relationship between the membrane material properties and the speed at which bacteria, organics and other particles built up on the surface. Hoek and fellow researchers engineered a membrane made of plastic polymers and specially designed nanoparticles, whose material properties are a closely guarded secret, and actually repel the impurities in water.

"They change the surface properties such that organics and bacteria have a harder time sticking to the surface," Hoek said. "So when the membrane is operating, filtering forward, instead of all these things being slammed up against the membrane and having them stick, they simply get washed away with the water that's also flowing across the surface of the membrane."

Furthermore, each nanoparticle is created with tunnels or pores in its structure. When placed in water, these tunnels, combined with the nanoparticle's secret material properties, actually attract water. This attraction makes water "want" to pass through the tunnels while repelling impurities. The result is a membrane that is many times more efficient, but can be manufactured and operated at virtually the same cost as current membranes.

Hoek estimates the membrane may reduce the cost of seawater desalination by 10 percent to 20 percent. In a wastewater application, Hoek said energy consumption might be reduced by 20 percent to 50 percent. But, he cautioned, these are just estimates and the membrane still needs testing.

"It's very exciting, very promising -- particularly because we have the ability to integrate into existing manufacturing infrastructure very quickly -- but still it needs to be field tested," he said. "The goal is to do this kind of field testing in the next year or two."

Cancer Bomb
Current chemotherapy is an imprecise way to destroy cancer cells -- it kills at least as many, and often more, healthy cells as it does cancerous ones. And patients typically suffer from various harsh side effects. However, Balaji Panchapakesan, assistant professor in the Department of Electrical and Computer Engineering at the University of Delaware, is trying to raise an army that will wage a new kind of war on cancer, where collateral damage is nonexistent and cancer cells meet a violent, explosive end.

Panchapakesan's strategy involves a battalion of carbon nanotubes armed with cancer-detecting radar and a propensity to detonate. According to Panchapakesan, by identifying proteins and the over-expression of certain molecules in a blood sample, cancer cells can be identified and isolated as they intermingle with healthy cells. Once identified, the cancer cells can be hunted down by Panchapakesan's specially trained carbon nanotubes.

"We coat the nanotube with a specific antibody," Panchapakesan said. "These antibodies actually attach to the receptors in the cancer cells. Then the carbon nanotubes are also attached to the cancer cells. Then we shine light onto the nanotubes and the nanotubes start heating up, and they can explode, killing the cancer cells."

The obvious advantage of carbon nanotubes attaching themselves to, and then detonating, cancer cells is that healthy cells are unaffected. If the cancer cells are near the skin, Panchapakesan said fuse-like light can be shone from outside the body, making a minimally invasive procedure. Even cancer cells hidden deep in the body could be eliminated relatively easily. Using an angioscope -- a fiber-optic device that can be inserted into blood vessels -- a surgeon could follow the carbon nanotubes to the cancer cells. Once they're found, the angioscope could provide the needed light to cause the cancer bombs to explode.

"If you look at chemotherapy, you have to undergo different stages, it's toxic, brings the immune system down, and you're prone to a lot of infection and other problems like nausea and hair loss," Panchapakesan said. "You can do this procedure again and again because it's noninvasive. Even if 30 percent of [cancer] cells are left behind, you can still have a better quality of life than using chemotherapy, because chemotherapy kills 80 percent or 90 percent of the [healthy] cells and only kills around 10 percent of the cancer cells. I think in about five years, the pace of cancer therapy will change completely."

Soldier of Fortune
Being a soldier today means access to incredible technology, advanced medicine and devastating weaponry. But today's soldiers must still carry heavy loads and an array of equipment, and they are vulnerable to all manner of bullets and bombs.

At the Massachusetts Institute of Technology's Institute for Soldier Nanotechnologies (ISN), the goal is to design and build a battlesuit for 21st-century combat -- a single piece of equipment that not only protects its wearer but enhances his strength, monitors his health, helps him recover from injury, allows seamless communication, and is no heavier or bulkier than a regular uniform. Although it sounds like science fiction, the U.S. Army already has invested $50 million to make the battlesuit a reality.

"Current technology as it relates to soldier equipment requires that desired capabilities be provided by various, distinct pieces of gear," said Franklin Hadley, ISN director of outreach. "Ballistic protection, for instance, is provided by the SAPI [small arms protective insert] plate enclosed in body armor, while radio communications are provided by a separate radio unit. As such, the soldier of today is encumbered by a great deal of equipment and weight. The concept of the battlesuit is the antithesis of this. Rather than a multitude of disparate parts providing a variety of functionalities, we envision integrating their functions into a single, sleek uniform."

The ISN research is divided among seven teams, and each contributes to a particular battlesuit element. These teams are attempting to develop materials that possess a number of fantastic properties. For example, such a battlesuit will consist of energy-absorbing nanomaterials that will defend against ballistics. These nanomaterials will form mechanically active devices embedded in the battlesuit itself. The fabric would switch between rigidity and flexibility, enabling the battlesuit to act as impenetrable armor when the nanomaterials detect an impact. The battlesuit may also be able to perform CPR on its wearer, as well as stiffen to act as casting material for broken bones.

"In addition to incorporating materials that will help protect a soldier from ballistic threats, we expect that the battlesuit of the future will include mechanisms to protect from chemical and biological weapons, as well as to minimize the risk of injury due to blast waves," Hadley said. "While the goal is certainly to keep a soldier healthy in all circumstances, there is always the risk of illness or injury given, if nothing else, the potentially dangerous environments in which he or she may be asked to operate. As such, we expect that the battlesuit will include technologies to not only monitor health, but also devices to provide emergency medical treatment should an injury occur."

Sensing and counteraction abilities are also in development. As Hadley mentioned, researchers are engineering nanoparticles that will provide soldiers with advanced biological and chemical threat detection without having to rely on separate equipment. In addition, the ISN is trying to develop biodevices and nanomaterials that will act as automatic first aid for wounded soldiers, doing everything from stopping blood loss to cauterizing wounds.

Such a battlesuit may sound like fantasy, but researchers and the military are serious about it. Hadley said one of the project's primary goals is to engineer nanomaterials to create a suit that does more to keep soldiers alive while reducing bulk and weight.

"A number of benefits to nanotechnology make it ideal for developing the battlesuit," he said. "Among them is the potential for dramatically reducing soldier load. A soldier's ... load can average between 60 and 140 pounds. While soldiers are extraordinarily fit, it is logical to expect that such weight could make operations much more difficult. By reducing weight, we make soldiers both more effective and safer."

Out of this World
Medicine and materials are probably the most practical applications for nanotechnology. But many consider the holy grail of nanotech to be an elevator.

An elevator and nanotechnology might seem like an odd pairing, and at the very least, not all that interesting. But imagine an elevator whose ground floor is in the middle of the ocean and the penthouse is on the 31,680,000th floor. This is the basic idea of the space elevator, a concept as old as the space age itself. Only now, thanks to carbon nanotubes, the material exists to actually build it.

"The elevator has been around in research and papers for more than 100 years," said Michael Laine, president and founder of Bremerton, Wash.-based Liftport Inc., a company actively trying to build a space elevator. "The father of the Russian space program, Konstantin Tsiolkovsky, envisioned the elevator right at the beginning of the space age."

Laine is serious about building an elevator to space. The idea was popularized in science fiction, but never approached anything close to reality because no material existed that could be used to build such a thing.

The basic concept for the elevator goes something like this: A paper-thin ribbon of carbon nanotubes -- maybe 3 feet wide -- would be created at a length of more than 60,000 miles. The ribbon, attached to a counterweight, would be taken into a geosynchronous orbit directly above an equatorial platform somewhere in the ocean.

With everything in position, the ribbon would be lowered from the counterweight down to the platform. Once connected to the platform, the ribbon would be kept taut by the orbiting geosynchronous counterweight. To visualize how this would work, imagine spinning a fully extended yo-yo in a circle. The person spinning the yo-yo is the earth, the end of the yo-yo the counterweight.

With the ribbon in place, robots called "climbers" would be brought to the platform where they would scale the ribbon. These climbers, powered by a platform-based laser targeting a climber's solar panels, would carry payloads with them, and once at the top, would simply let go and the payload would be in space. The space elevator would, once built, make space access far more inexpensive and safer than rocket launches.

Even though the proper materials exist, building a space elevator is an enormous challenge. Liftport has made progress already, however, and has run successful tests of scaled-down versions of the elevator.

"We've built a robot that climbs up and down a string," said Laine. "We've actually built a bunch of them. We've built platforms that have hung as high as a mile in the sky off balloon-based systems. We've had a robot that has climbed 1,500 feet."

Their next test is far more ambitious.

"We're working on a system that will be 30,000 feet," Laine said. "We're probably going to fail."

But like most nanotech projects, the dream of a space elevator suffers from the critical limitation Miller mentioned -- no one has been able to mass-produce nanotubes. Laine himself readily admits that Liftport's objective is utter fantasy until mass-production is possible. That's why Liftport operates a laboratory in New Jersey. It is working feverishly to develop an affordable process to manufacture sufficiently large quantities of carbon nanotubes.

"Until you can start getting these things traded on the Chicago Board of Exchange as a commodity, all these wonderful visions of the future are not going to happen," Laine warned. "[Globally people are] only making 100 pounds of this stuff a day. Until you can mass-produce this stuff, it's just science fiction. So our space in New Jersey is not about being a research lab, what we're trying to do is commercialize somebody else's stuff. So we're working with a couple of different labs that look like they have processes that lend themselves to being mass-producible."

Despite the incredible challenges, Laine is optimistic he will build a space elevator. In fact, the company Web site has a counter that shows just how long it will be until the space elevator is open for business. At press time, there were only 24 years, 260 days, 22 hours, 21 minutes and 28 seconds to go.
Chad Vander Veen

Chad Vander Veen is the former editor of FutureStructure.