By David L. Brown
Nanotechnology is the fast-growing science of the extremely small. The prefix “nano,” from a Greek word for “dwarf,” means one-billionth. So, anything that can be measured in nanometers, which is one billionth of a meter (a meter is about 40 inches), is very small indeed. It takes about 80,000 nanometers to measure the width of a human hair. To put it in another perspective, a nanometer is to a meter as one inch is to 15,783 miles, more than three times the distance between New York City and Honolulu.
Thanks to the development of equipment such as scanning electron microscopes, scientists have been learning to work at this sub-microscopic scale to create new materials with useful potential in such areas as energy production, water purity, computing and medicine.
But there’s a fear factor surrounding the subject. It’s mainly concerned with hypothetical “nano-machines,” molecule-sized mechanisms imagined to be able to perform physical tasks and perhaps even to reproduce. That idea when carried to an extreme is described with fictional horror by writers such as Michael Crichton. One of his recent books, “Prey,” describes nano-machines that have the ability to swarm, creating semi-intelligent artificial beings that run amok and threaten human existence.
In reality, nanotech has little or no chance of becoming a threat such as he envisions, any more than his reconstituted dinosaurs likely will ever roam the Earth.
In fact, there’s much to suggest that nanotechnology is as promising — and as safe — as proponents claim. The nanotech field is an active and exciting one, with almost daily progress being reported in a wide range of fields. According to the National Nanotechnology Initiative (NNI), a government agency, nano-scale materials already are being used in “electronic, magnetic- and opto-electronic, biomedical, pharmaceutical, cosmetic, energy, catalytic and materials applications.”
Much of today’s clean water research “is focused on nanotechnology, which many believe will be a major contributor to new industrial and public water purification systems,” according to the NNI website. It mentions as an example a recent report in Science magazine on a method of using nano-sized particles of an iron compound to increase the ability of purification plants to remove arsenic from water. The process could improve arsenic removal by a factor of ten, according to the researchers.
Arsenic pollution is a concern in parts of the U.S. and in some Third World regions it poses a major health problem. For example, another article in a recent issue of Science magazine describes the high incidence of arsenic toxicity in India and in nearby Bangladesh where “more than 82 million people live in contaminated areas.” The article quotes Allan Smith, an epidemiologist at the University of California-Berkeley, who says the scourge in the Subcontinent is the “largest poisoning of a population in history.” Plainly, the new nanotech process could be a boon to those nations.
Another exciting area of nanotech research and development is the application of carbon nano-materials such as fibers and tubes. These have many potential uses. For example researchers at the Lawrence Livermore National Laboratory say they have developed a method of using membranes containing carbon nano-tubes to cut the cost of purifying water from the ocean by up to 75 percent. That desalinization technology could go a long way toward providing a solution to declining supplies of fresh water in many parts of the world.
Here is a sampling of other news about nanotech developments, just from the last few days:
• Researchers at the Georgia Institute of Technology have developed a “new class of electronic components that could lead the way to bendable and battery-less electronic devices inside the human body — which could monitor blood flow, organ activity and other vital signs,” according to the Nanotechnology.com website. The process uses zinc oxide nanowires.
• A team at Notre Dame University has demonstrated a way to “significantly improve” the efficiency of solar cells using low-cost materials. The technique uses carbon nano-tubes and a film of titanium-dioxide nano-particles. The low-cost cells could be used to make hydrogen for fuel cells directly from water. The story was reported on the Technology Review.com website from the Massachusetts Institute of Technology.
• In a paper published in the March issue of the Journal of Nuclear Medicine, researchers at the University of California-Davis describe how they attached heated “nano-probes” made of magnetized iron-oxide particles to slow the growth of aggressive breast cancer cells in mice. This resulted in “a tool that could confine the treatment to [a] tumor while sparing the surrounding tissue,” according to a Reuters report.
There is no doubt that we are entering a promising new world, a nano-world that offers many challenges and opportunities for the future. There are some who warn of dangers, but the objections appear lame to my jaundiced eye. We hear talk of the world being engulfed in “gray goo,” an imagined substance made up of trillions of self-replicating nano-machines. That has the ring of scare tactics to me, having more in common with fairy tales than science.
A web site from the Center for Responsible Nanotechnology (CRN) provides a list of supposed nano-tech “dangers.” First on the list is “economic disruption from an abundance of cheap products.” Gee, that shouldn’t be worrisome except to Chinese manufacturers. And what is the second concern? “Economic oppression from artificially inflated prices.” Well, CRN, which is it? Those are flimsy arguments indeed.