It’s not a question of ‘if’ nanotechnology will shake the world, but ‘by how much’.
Held aloft by an electric field, an infinitesimally-sized piece of gold begins to vibrate. The gold particle is so tiny that it is swaying in the sound given off by nearby bacteria. Researchers at Munich’s Ludwig Maximilians University unveiled their invention earlier this year of a microphone so sensitive that it can distinguish between nearly identical strains of bacteria by the vibrations they make. This “nano-ear” is capable of picking up sounds over a million times fainter than the human ear can.
Nanotechnology is innovating almost every field of science and technology. From the detection and prevention of infectious diseases to the collection of solar energy, the implications of working with particles on the nanoscale are wide reaching. The applications of nano developments will revolutionize many areas of society with new technologies as well as with cost-effective replacements of old ones, and both types of advances will have implications around the globe. There is reason to be both hopeful and cautious of what this new level of innovation can accomplish for both the wealthiest and most impoverished nations on the globe.
The all-encompassing field of nanotechnology will soon play an invisible role in every aspect of society. Nanotechnology is a catch-all term for any form of innovation that comes out of the specific manipulation of particles on the nanoscale. A nanometer is one-billionth of a meter, and it is the scale on which atoms and molecules are measured. Comparatively, if human beings were only a nanometer tall, planet Earth would be merely 7.5 millimeters wide.
A ‘nanoparticle’ is any particle that is best measured in nanometers. Nanoparticles are of a size that is roughly the length a fingernail grows in the time it takes to read this sentence. Every atom and molecule is a nanoparticle, and thus the nanoscale exists naturally in the world. Nanotechnology is any technology that is developed as a result of meticulously working with specific atoms and molecules.
To start with, this manipulation allows for smaller technology. The public imagination immediately leaps to such proposed inventions as ‘nanobots’ — miniature machines that could, for instance, autonomously conduct medical procedures within the human body. Nanotechnology, however, is not only the development of microscopic computers that function much as their larger counterparts. There is something unique in the properties of particles that exist on the nanoscale. The Journal of Nanotechnology Online describes how “when dealing with matter below approximately 50 nanometers, the laws of quantum physics supersede those of traditional physics”. Nanoparticles may have a different “conductivity, elasticity, reactivity, strength, color, and tolerance to temperature and pressure” than the same material on a larger scale. Taking advantage of these differences allows for brand new innovations which have no precedence in technology of a traditional scale.
Nanotechnology got fully underway after the 1981 invention of the scanning tunneling microscope, which is an instrument that images surfaces at the atomic level. Beyond simply depicting nanoparticles up close, however, scientists discovered that they could use the microscope to actually touch individual atoms and carefully move them around. Nanotechnology sprung out of such intentional arrangements of atoms and molecules. Those responsible, Gerd Binnig and Heinrich Rohrer, were awarded the Nobel Prize in Physics in 1986 for their achievement. Scientists became much better able to observe and manipulate interactions between atoms, and so they began to develop new technologies as a result of both better understanding certain reactions and intentionally manipulating such small particles.
The Computer of a Lifetime
Stepping away from the concept of microscopic machines, one invention in particular illustrates how diverse the use of nanotechnology can be. Central Japan International Airport has nearly 15,000 panes of glass on one face of the building. They are kept clean using a nano invention. Titanium Dioxide clusters less than 10 nanometers in diameter coat the windows. They are invisible to the human eye, but when excited by the sun’s UV rays, this photocatalytic coating breaks down dirt clinging to the window, allowing it to float away on a gentle breeze.
One of the earliest and greatest discoveries of nanotechnology is the carbon nanotube. Carbon nanotubes are single molecules of carbon atoms bonded together in the shape of a tube. The walls of the tube are made up of a hexagonal lattice of carbon atoms. The lattice wraps in on itself to form the hollow tubes that can be many million times longer than they are wide. Collected in multitude, carbon nanotubes could look like nothing more than a fine, black powder to the human eye. Their uses, however, are many.
Foremost, carbon nanotubes are the strongest material ever discovered in terms of tensile strength and elasticity, far surpassing the capabilities of steel for some uses. But their unique, hollow nature makes them not nearly as strong under compression or bending stress. For the right uses, however, carbon nanotubes can maintain the same strength as other materials at a drastically reduced weight. Already nanotubing is being used in high-performance sports equipment such as tennis rackets and bicycle frames. The number of applications is growing, including possible uses in light-weight structures. Hypothetical uses proposed by some scientists include cables that attach space stations to our planet’s surface to guide independently-propelled elevators directly to the satellites.
Carbon nanotubes also have very unique conductive properties. According to the Journal of Nanoparticle Research, carbon nanotubes are only about as conductive of thermal energy across their width as soil. Along their length, however, they are nearly ten times as conductive of thermal energy as copper. When it comes to electrical current running along its length, carbon nanotubes can theoretically reach an electric current density up to 1,000 [times] greater than that of copper.
This has significant implications for both decreasing the size and increasing the processing power of computers of the future. A carbon lattice called graphene that is similar to that in nanotubes is currently being tested by researchers at IBM’s T.J. Watson Research Center in the United States as a potential replacement for conventional silicon in computer microchips. While silicon conductors have a significantly larger limit of how close they can be placed next to each other before interference occurs, graphene is the next step in shrinking computer processors as its conductors can be packed much more densely together. Nanotechnology is creating a very plausible method to fit the processing power of today’s computers into dramatically smaller apparatuses. Such computers could be worn as glasses, an ear piece, or even internally attached directly to a user’s brain using other nano developments that allow prosthesis to better connect with nerve fibers.
Computers developed with nanotechnology can even go a step further, however. Professor Jim Gimzewski of UCLA is currently collaborating with Japanese physicist Dr. Masakazu Aono to create a “neuromorphic computer”. On the nanoscale, the atoms in silver molecules protrude slightly when a current is passed through them. This discovery was initially investigated as a form of computer “on-off”, or binary, switch as the protrusion can create a conductive bridge between nearby silver molecule chains. The benefit was first thought to be only how small the technology allowed such binary switches to be manufactured.
Gimzewski, however, saw another use. The silver atoms remained in their configuration for a short time after the current had finished flowing. This reminded Gimzewski of how the human brain creates memories by establishing connections through which electrons can flow. By using a configuration of silver atoms that is reminiscent of the tangled web of brain synapses, Gimzewski seeks to model a computer off the human brain. The research is in its infancy now, but rather than being hard-coded with processes, such a computer could learn through repetition much the way a developing human brain does. Through nanotechnology, the possibility exists for an artificial intelligence that could be taught — rather than programmed — to think.
Nanotechnology’s implications for the health sciences are just as profound and run the range from the convenient to the lifesaving. Chad Mirkin, director of the International Institute for Nanotechnology at North Western University, explained to the CBC’s David Suzuki in interview how new developments have changed diagnostics:
Nanotechnology is bringing a revolution to medicine in many different areas. On the diagnostic front, it’s going to create very accurate, very sensitive tools that enable point-of-care diagnostics. The point-of-care being hospitals, the emergency room, and one day, the doctor’s office and at home.
Operating on a smaller scale allows for both greater accuracy and greater efficiency. The first signs of a disease appear within the human body on the nanoscale, and being able to detect them right away could save lives. In addition, using newly-developed screening methods as replacements for old ones, a multitude of tests for diseases, viruses, and even genetic predispositions can all be completed on a single sample of blood. This is both cheaper and quicker than the formerly required multiple vials that were often sent away to different laboratories.
Combining these two innovations, there is a potential for medical diagnostics of the future to be carried out continuously by implanted devices that are monitored by the patient themselves. The previously mentioned computer attached directly to the brain could report on viruses that have newly entered the bloodstream as easily as it could access the internet to check the weather for its user.
Returning to the present, new developments are already helping with medicine delivery. A concept as straightforward as pH-sensitive gels that breakdown at a specific pH level was made possible through nanotechnology nearly a decade ago. Such a gel can be used to treat patients with multiple sclerosis more efficiently by allowing coated drugs to release at varying rates depending on the pH of the surrounding environment.
The concept of targeted-delivery is now revolutionizing the treatment of cancer. Earlier forms of chemotherapy targeted the cancerous cells, but they also targeted nearby healthy cells. This led to the many difficult and painful side effects associated with chemotherapy. In an orally administered treatment, for instance, less than two percent of the drug makes it to the tumor, and the rest creates unwanted toxicity in the body. Better-targeted applications of chemotherapy developed through nanotechnology not only reduce side effects, but allow the concentrations of the drug to be greatly increased at the target area, increasing its effectiveness.
Dr. Omid Farokhzad at Harvard Medical School has developed such a method. His targeted delivery protocols are the first in the world of its kind to enter human clinical trials. He explains its benefits in an interview with Suzuki:
In the context of a nanoparticle, you can increase the amount of drug at the tumor site by 20-fold. In order to achieve that level of tumor concentration of a chemotherapy drug, you would have to deliver a very high dose of chemotherapy, which would actually be lethal to the patient, but in the context of a nanoparticle, you can actually have complete tumor eradication.
By working on the nanoscale, his methods deliver medicine in particles less than ten nanometers wide, which are so small that they can roam the body freely. Using Farokhzad’s incredible techniques, the drug to be administered is first coated in a dissolving plastic to allow for its safe delivery; it is then disguised by water molecules to evade eradication by the body’s immune system; and finally it is coated in ligands that bind to specific receptors that grow only on tumor cells.
His research may soon have uses in many other forms of treatment. Farokhzad says that “what we are seeing today is just really the tip of the iceberg. The medicine that we’re going to be practicing thirty, forty, or fifty years from now will look nothing like today.”
The Potential for Green
In addition to computers and medicine, nanotechnology is also leading to innovations in sustainable living. Ted Sargent of the University of Toronto is working at the nanoscale to dramatically increase the efficiency of solar energy collection. Though complete reliance on solar energy is only a pipe-dream, he points out in an interview with the CBC that the amount of energy that strikes the earth’s surface every hour is enough to meet the energy demands of every country on the planet for an entire year. Low-cost, high-efficiency solar cells are one way to help meet the world’s energy needs and decrease dependency on crude oil.
Nanotechnology is leading to such solar cells. Current solar panels are only able to harvest energy from the sun’s visible spectrum of radiation. Using carefully prepared nanoparticles, Sargent hopes to be able to easily double the efficiency of solar panels:
Fully half of the sun’s energy lies in the infrared frequencies. My research acknowledges that we need to capture all of that energy if we’re going to make an efficient solar cell … When we make three different batches of nanoparticles, we can program them each to be responsive to do different slices of the sun’s spectrum.
In addition, he hopes to be able to move beyond the conventional panel model for solar cells. His nanoparticle solar cells are lighter and flexible, theoretically able to be deployed on sails or even clothing, and they are cheaper as well. Rather than using isolated panels, Sargent says of his new solar cells that “by virtue of their lower cost, you won’t hesitate to deploy them across the entire surface of a building”. Through such low-cost, high-efficiency solar cells, gathering even 1/10,000 of the sun’s energy to meet the world’s needs seems slightly more plausible.
While Sargent’s solar cells are only in development, nanotechnology is already creating cheaper methods to meet the world’s environmental needs. Even though arsenic concentrations in drinking water have been linked to cancer, more than 55 million people around the world still drink water that is contaminated with the toxin. Guanajuato, Mexico, is a city of some hundred thousand people with heavy arsenic concentrations in its ground water. One relatively cheap solution is already being tested there is a filtration system of incredible efficiency thanks to nanoparticles.
The Journal of Nanotechnology Online points out that one of the strengths of nanoparticles is their incredible surface-to-volume ratio. The smaller the particles of a substance are, the more surface area the substance possesses. Such a simple concept of geometry has profound advantages in reactions that are based surface-to-surface contact. Ferrous oxide, or rust, naturally bonds with arsenic. A filter made out of billions of tiny ferrous oxide nanoparticles can very cheaply and efficiently clean arsenic from ground water that passes through it.
This strength of the surface area of nanoparticle solutions is also being used to clean emissions and increase the efficiency of diesel engines. A diesel additive of cerium oxide nanoparticles eliminates pre-existing nanoparticles in diesel engine exhaust that have been linked to heart attacks in those breathing in the fumes. In addition, as the cerium oxide additive is used up in the diesel, the oxygen it releases greatly increases the efficiency of the combustion engine.
Another such nanoparticle chemical reaction helping to clean the environment is being developed by Professor Dennis O’Carrol of the University of Western Ontario. Costly chemical spills that normally require excavation to clean up are being dealt with by nanoparticles that can be pumped into the ground water. The nanoparticle solution reacts with appropriate contaminates, breaking them down into their harmless components, and allowing them to be flushed out. At peak efficiency, the resultant runoff water then contains only naturally occurring molecules that are otherwise drinkable.
Nano on a Global Scale
With the vast diversity of innovations coming out of the growing field of nanotechnology, it is not surprising that it has a crucial role to play in the progress being made in the developing world. The U.N. Conference on Trade and Development and the Commission on Science and Technology for Development both suggested early on that nanotechnology can help “reduce the cost and increase the likelihood of attaining the Millennium Development Goals”. The Journal for Nanotechnology Online reports that “individuals with the National Science Foundation of Sri Lanka believe that, whilst nanotechnology research and development is ‘high-tech’, the products it enables can be appropriate for use throughout the world”. Likewise, the U.N. Under-Secretary for Economic Affairs pushed to include nanotechnology in discussions concerning emerging technology and sustainable development.
Many of the applications of nanotechnology have obvious roles to play in developing nations. In 2005, the Public Library of Science published a report ranking the top ten applications of nanotechnology for their potential to help reach the U.N.’s Millennium Goals. Research of the greatest applicability was deemed to be in the area of energy storage, production, and conversion, which could help ensure environmental sustainability. The long-term benefit of such technology is significant, but other areas of nanotechnology are able to contribute more immediately.
Agricultural productivity enhancement ranked second where innovations in areas of plant fertilizers and nutrients and drugs for livestock are already having immediate returns for combating hunger, something that is at the root of many of the obstacles of the Millennium goals. Water treatment, disease diagnosis/screening, and drug delivery systems, such as those discussed earlier, ranked third, fourth, and fifth respectively.
Many see the medical applications of nanotechnology as some of the most critical for improving quality of life in developing nations. Safer and cheaper diagnosis and treatment of diseases are at the core of alleviating suffering in rural areas, but simpler to use methods developed through nanotechnology are also able to help by freeing up the limited medical staff in such situations. In rural areas, energy innovations are also able to aid the quality of medical treatment. Groups in the U.S., India, and Mexico have been working jointly on inexpensive and maintenance-free solar panels aimed at providing rural clinics with the necessary electricity to stay in operation and importantly keep medications refrigerated in areas where electricity is unreliable.
There are still hurdles to overcome, however. Foremost, technologies for developing countries must take into account their realities. Many proposed innovations for impoverished areas have turned out to be overly expensive or inappropriate to their circumstances. Solutions for such areas need to be tailored to their situations. Thankfully, the efficiency of many nanotechnologies already makes them a better choice for impoverished areas than the solutions that already exist.
Worries still exist, however, that nanotechnologies will become another import upon which developing nations are dependent, only increasing the economic divide. Though their implementation is often relatively inexpensive, research and development into nanotechnologies is costly, an expense affordable mostly by developed countries. China and India, however, have established national activities in nanotechnology research and continue to make great strides. Thailand, the Philippines, South Africa, Brazil, and Chile all have some form of government support or national funding for nanotechnology programs, and many other countries now have private enterprises following suit. So long as investment into nanotechnology research does not heavily detract resources from critical issues in developing nations, the chance even exists for such countries to leap to the forefront of this relatively new industry and become powerful exporters of the technologies in their own rights.
The diverse and pervasive industry of nanotechnology is hardly predictable on a technological front let alone an economic one. The only certainty is that it will have profound implications for the societies of tomorrow in both developing and developed nations.