Nanotechnology: A Chemist's Perspective
Nano' has been in fashion for a while now. Apple named their iPod Nano for a reason to imply how small it is. But does the general public know what nano' and nanotechnology is? Some of my non-science friends affiliate nanotechnology with computers. Given the 2007 Nobel Prize in Physics for "relates to iPods," nano' may be synonymous with iPods as well. But what is it, how do we define it and what can we use it for?
Nanotechnology is much more than the technology behind an iPod or computer component. Explaining its complexity and diversity is a daunting task. Nanotechnology is the study of molecular science on the nanometer scale, a billionth of one meter. At this scale, nanotechnology is based on isolated or synthesized components from man-made inorganic' materials, the materials used in computer chips, or live organic' materials, cellular components, DNA and proteins. The term nanotechnology was coined in 1974 by Norio Taniguchi to describe how atoms and molecules are deposited in very thin layers in the semiconductor industry. In particular, he refers to the manipulation of a single atom or one molecule. However, the initial ideals of nanotechnology were described in 1959 by Richard Feynman, a physicist. , His famous talk "There's Plenty of Room at the Bottom" was revolutionary and predictive of what was to come. Another founding father of nanotechnology is K. Eric Drexler. He described self assembly and molecular motors in 1981, protein nanobots that would do the work for us. , In these articles he describes biological analogies of technology functions at the molecular level.
Interdisciplinary Nature and New Technology: Microscopy
Nanotechnology draws on several distinct scientific fields: material science, engineering, physics and chemistry, to name a few. Even a new field of nano ethics has emerged as a result of the explosion of this new field. The interdisciplinary nature has acted as a catalyst for the explosion of new discoveries. Advances in technology have also fueled discoveries. Microscopy is one advance with a huge impact. The first prototype electron microscope was built in 1931. We would never see the nanoworld without it. We all know what a microscope is. Microscopy is similar to using a microscope but electrons, a scanning probe or light are used to create images. New technologies such as the scanning electron microscope (SEM) and work on surfaces in vacuums have revealed the movement of atoms on surfaces. Professor John Polanyi, a 1986 Nobel Laureate in reaction dynamics, is a nanotechnologist' that works on creating self assembly of nanoparticles. With the visual aid of the SEM he can see molecular reactions of halogenated compoundson silicon surfaces. Don Eigler was also another nanophysicist' who used scanning tunneling microscopy (STM) in 1989 to spell out the letters IBM with xenon atoms. The ability to move atoms has important implications for data storage; it is how data is stored.
Nano Ethics, Nanomedicine and Nanobiology
Nanotechnology is based on new materials not much is known about the safety of these materials in the human body. One professor in the field of nano ethics is George Khushf of the University of South Carolina. In a presentation at the International Institute for Nanotechnology (IIN) in 2007 he addressed the idea of anticipating of safety issues vs. dealing with safety at a later point. Given the recent controversy of iPods and iPhones safety should always be considered when human use is involved. One question that arises is, "Do scientists carefully choose the chemicals they work with in anticipation of health concerns?" In particular, Professor Paula Hammond of MIT works on layer by layer nanomaterials that can be used in the joints of hip replacement devices. Given the knowledge that these devices will be used in vivo how does this impact the research she is undertaking? Many researchers in nanomedicine and nanobiology are looking ahead to address the safety of materials such as buckytubes and other nanoscale devices in humans at the Center for Biological and Environmental Nanotechnology.
What can Nanotechnology be used for?
One famous nanomolecule is the buckyball. Buckyballs or buckminsterfullerines were discovered by Richard Smalley of Rice University in 1996. They are created in the gas phase using carbon and are the third form of carbon, after diamond and graphite. They look like a molecular soccer ball and are named after the American architect, Buckminster Fuller. Smalley passed away in 2005, but his work continues on at the Smalley Institute. Many variations on buckyballs are being researched for biomedical and nanotechnology applications and the ethical issues continue to crop up, as toxins might bind to buckeyballs and in some cases carbon nanotubes and punctured the lungs of rats.
But nanotechnology has the capacity of doing good. Nanotechnology is being used to remove arsenic from water. Vicki Colvin of Rice University uses magnetite nanocrystals, Fe2O3 to remove arsenic from water through a magnetic interaction. One aspect of her work is creating an accessible synthesis of magnetite by using materials that are found in the third world. In Nicaragua they will be able to make magnetite by using olive oil or coconut oil, a deep fat fryer, laundry soap and rusty old metal. Nanotechnology is being used at the University of Texas El Paso to look at phytoremediation. Phytoremediation is the cleaning up of heavy metals in soil by plants. Plants such as the mesquite plant have the ability to sequester toxic chromium from soil in the form of nanoparticles. There are other heavy metals that can be "absorbed" by plants as well.
Nanotechnology is being used to create electricity from waste heat. Mercouri Kanatzidis at Northwestern University is using lead telluride nanoparticles to derive electricity from heat. These thermoelectric devices might be used in car engines to scavenge wasted heat. However, the efficiency of these devices must be optimized before a practical application can be realized.
There are many potential areas where nanotechnology can potentially improve the quality of human life. Given its interdisciplinary nature not only within science, but also its ethical implications it is a field that we should be aware of. The large quantity of discoveries that are on the brink of existence should motivate us to educate ourselves about the benefits and risks of a brave new world of nanotechnology. Overall, nanotechnology promotes a healthy debate over the future of science "at the bottom."
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