The U.S. National Science Foundation (NSF), a strong supporter of nanotechnology, calls it the next industrial revolution. Most scientists and engineers view it as a vastly more powerful technology than any they've ever seen. Billions of dollars are being made available worldwide to fund it.
We're talking about nanotechnology, the ability to manipulate and organize matter and structures at atomic and molecular scales, working with feature sizes on the order of 1 nm and smaller (1 nm equals the span of seven to 10 hydrogen atoms). The U.S. government has already allocated $3.7 billion for nanotechnology, under the National Nanotechnology Initiative (NNI) of the NSF, through fiscal year 2008, as spelled out in 2003's Nanotech-nology Research and Development Act.
Although few if any commercially available nanotechnology products have been realized so far, there's near-unanimous consensus within the engineering and scientific communities that the technology is for real. Much of what has come on the market consists of tools, equipment, and materials for use by researchers in their dogged investigations of the technology. But nearly everyone envisions it as "the lab to the fab" and that nanotechnology will be an enabler of exciting things to come. But the larger question is... when?
No one sees many commercial nanotechnology products within the next two to three years, excluding the aforementioned laboratory tools and certain coating materials. Given the large levels of nanotechnology funding from governmental, academic, and private industry entities worldwide, it's obvious the scientific community believes in its viability. And expectations are running high, given the amount of hype. So it's no surprise that coming out of the woodwork are the naysayers and doubters who believe nanotechnology may lead to "nanoprofits," and therefore the technology will not be viable.
The best estimates are that it will take at least 10 to 15 years for nanotechnology to mature into full-blown commercially available products. Some researchers believe that this estimate is too conservative and that four to five years is more likely. But such viewpoints are in the minority.
One problem is nanotechnology's disruptive force on the top-down approach used by the semiconductor IC industry, which tends to squeeze more and more functionality into smaller and smaller pieces of silicon. As a result, semiconductor researchers are discovering that you can only make feature sizes so small before being forced to deal with more fundamental issues, like the chemical, biological, and quantum properties of all types of materials, not just silicon. It's this bottom approach that pure nanotechnology researchers are following, trying to get a better understanding of atomic and molecular structures of materials and how they can be manipulated to perform specific functions.
Proponents of the bottom-up approach foresee the eventual creation of the smallest self-assembling molecular machines, opening up a new era in our understanding of biology and technology. Like viruses or bacteria, these machines will have the power to duplicate themselves so they can multiply like living entities and reshape the environment around them.
One of the most obvious manifestations of nanotechnology research is the carbon nanotube (CNT), both in single-walled and multi-walled versions. CNTs are fullerene-related structures that consist of graphene cylinders closed at either end with caps containing pentagonal rings (Fig. 1).
CNTs form the basis of a vast number of structural elements whose properties can be customized to perform specific functions by changing their molecular structures (Fig. 2). These properties can be electrical, mechanical, and chemical, allowing CNTs to be used in a vast number of applications, including computers, health care, energy, materials, environmental, aerospace, and manufacturing applications.
Structural formations with different mechanical, electrical, and thermal properties can be achieved. As a result, it's easy to obtain durable motors and gears, actuators, sensors, and cubes. A host of electronic functions, such as quantum-wire interconnects, logic elements, memories, and single-electron transistors are possible (Fig. 3). The end result will be more powerful tiny computers, large-screen low-power flat-panel displays, strong composite materials, tools for in-vivo health diagnostics, prognosis and therapeutic treatments, ultra-strong fabric fibers, artificial muscles, robots, and bionic human organs. Nanotechnology can even improve futuristic structures like spacecraft (Fig. 4).
Interest in nanotechnology remains strong in the academic and government sectors, and it's beginning to seep into the laboratories of major electronics companies like Intel, Texas Instruments, and IBM. Despite the funding these companies have in nanotechnology R&D, many in industry are arguing for even greater involvement, looking for industry to lead the way instead of academic and governmental laboratories.
As already mentioned, don't expect any overnight successes. Within 15 years, though, watch for nanotechnology to reach the level of intra-cellular molecular machines. This will eventually lead to the "nanofactory," where environmental pollution caused by present-day factories will be vastly reduced if not altogether eliminated, restoring the health of our natural environment.
In retrospect, it's important to step back and realize that technology can be a double-edged sword. While the extraordinary properties of nanoparticles could enable everything from extremely sensitive diagnostic tools to super-strong materials, these same particles can be so small that they could also negatively impact the human body (by passing into the skin and lungs) and the environment (by lingering around as undetectable pollutants). In fact, there's a collective effort under way among corporate, academic, and government researchers to gather more information about these potential dangers. Thanks to a $4 million solicitation for research proposals issued last year, the U.S. Environmental Protection Agency is funding about a dozen studies that will investigate the health and environmental effects of nanomaterials.
Technical data on the dangers is lacking at the moment. But the long-term hope is a better understanding of nanotechnology to satisfy the objections of skeptics and critics, ultimately opening up vast commercial opportunities.