Imagine the ability to build anything you need, atom by atom. Imagine the capacity to heal the body by reassembling the atoms of ailing cells, and by replacing sick or dead tissues with entirely new, healthy tissues built from the atom up. Imagine the ability to release tiny, molecular warriors into polluted water—warriors with only one function: to isolate pathogens and pollutants and eliminate them, leaving clean, potable water behind. Sounds like science fiction? Not anymore. Now it's just the point where scientists from various disciplines meet to create the world of nanotechnology.
Nanoscale: The Numbers
Nanotechnology typically concerns things that measure between 1 and 100 nanometers. Things which are even smaller are on an atomic scale, and things which are larger are considered to be on the microscale.
To really understand the amazing field of nanotechnology, we must comprehend the tiny scale of the units of measurement involved. A nanometer (nm) is one-billionth of a meter. That is a hundred-thousandth the width of a human hair. Of course that's still bigger than an atom; an atom has a diameter of about 0.1 nm, and its nucleus is only 0.00001 nm in diameter. These are sizes that are essentially impossible for us to comprehend without lots of context; check out this animation to understand the scale of the universe including the nanoverse.
Atoms are the most basic units in the universe; everything around us is made up of atoms. These tiny building blocks assemble to form everything from the basic elements to the most complex machines. In fact, the reason that the nanoscale is so special is that it is the point of construction and engineering at which atoms are assembled into working structures.
What kind of scientists work on the nanoscale? Biologists, chemists, engineers, physicists, and others all work in nanotechnology. In fact, effective work in nanotechnology demands mastery of multiple scientific disciplines.
Quantum mechanics in particular is crucial to an understanding of nanotechnology. The ways that materials behave on the nanoscale are very different than how we have come to understand classical physics in our day-to-day lives. Without the study of quantum physics, the behavior of substances at the nanoscale can seem unpredictable, or even contrary to reality. In short, we are relearning everything we “know” about the properties of substances at the nanoscale so we can understand how we will be able to use them practically moving forward.
Beginning to Use What We Know
What are some practical applications for nanotechnological advances right now? Two of the most commonly used nanoscale structures now are nanowires and carbon nanotubes. Nanowires are wires with tiny diameters, less than 100 nm, and as small as 1 nm across. Scientists and engineers are experimenting with nanowires with the goal of creating smaller, more powerful transistors for computer chips and microprocessors.
Even more commonly used now are carbon nanotubes, which are cylinders constructed from carbon atoms on the nanoscale. A sheet of carbon atoms would appear to be a sheet of hexagonal units linked together; to make tubes, the sheet is then rolled. There are different ways to “roll” the sheet (or linked hexagons) into tubes, so different carbon nanotubes have different characteristics and properties. Some configurations can be semiconductors, for example. Why does all of this matter?
The right structure can create a carbon nanotube that is hundreds of times stronger than steel and six times lighter. These would be used in construction of all kinds, but especially in the building of vehicles; the added strength would improve safety and the lighter weight would improve fuel efficiency.
In fact, there are many products on the market which already use nanotechnological advances. Antibacterial bandages, sunscreen, and toothpastes already improve our health. Various types of next generation glass and scratch-resistant coatings improve our safety and convenience. Clothing that resists staining, odors, and water is another convenience that we enjoy thanks to nanotechnological advances.
What's to Come
On the subject of nanotechnology and the future, the idea of the “Star Trek” machine called the “replicator” frequently comes up. On the old show, the replicator could simply produce any object out of thin air. Now, scientists see this kind of technology as a possibility with the use of nanotechnology.
The first step in building a replicator would be to create a machine called an “assembler.” Because these nanoscale machines would be so small, you would need trillions of them working in concert, each assembling atoms towards a common goal, and in the end producing matter according to a pattern. This kind of molecular manufacturing is no longer so far afield as it once might have seemed; between nanoscale machines that can work to put atoms together in any pattern we tell them to and, for example, 3D printer technology, these are ideas that are within reach.
Another major area for the future of nanotechnology will be medical nanorobots. These nanorobots will be consumed by patients and will attack pathogens, cancer cells, viruses, and other problems inside the human body as programmed. It is also possible that they will be able to prolong life by rebuilding damaged cells or by replacing unhealthy tissue with rebuilt, healthy tissue. Taken further, experts speculate that nanorobots may someday be able to operate on patients from within them, eliminating most of the risk that comes from surgery.
Nanotechnology also has powerful promise for environmental applications. Nanoparticles and nanorobots could be used to target pollutants, clean oil spills, remediate water, and otherwise improve the environment.
Immediate challenges that face the scientific community right now include the need to understand how quantum mechanics impact all materials at the nanoscale. We just don't know how all substances behave at the nanoscale. This means that there are valid concerns about the toxicity of nanoparticles, especially since they can easily penetrate various biological barriers and enter human bloodstreams, tissues, and brains.
Other ethical concerns about the possible weaponization of nanotechnology and the use of nanotechnological advances to enhance human capabilities are also notable. Alongside these issues is the overall issue of access to the technology. How can we resolve these concerns in a satisfactory way?
There is little doubt that nanotechnology is a fascinating area that will continue to present our society with breakthrough solutions to problems, as well as puzzling ethical questions. Open dialogue about nanotechnology is one of the best ways to ensure that we are fully prepared to handle what comes next from our forays into the miniscule.