Nanotechnology

Recent Advances in Nanotechnology

Discovery of nano-graphite stimulates a new direction for research to find a better way to store hydrogen fuel.

More on page 2.

Nanoscale fiber optics has recently been fabricated from phospholipids.

More on page 2-3.

Thoughts on wiring the brain on a nanoscale are now much more possible because of tiny nanowires.

More on page 3.

The invention of the first nanovalve may allow for molecules to be controlled on a nanoscale.

More on page 3.

Nanopores, which have a varied amount of uses, have been on the market and their sale has been projected to increase in the years to come.

More on pages 3-4.

Background of Nanotechnology

The size of a mite compared to the size of nanotechnological gears.

Nanotechnology consists of technological developments that can be measured on the nanometer scale, usually 0.1 to 100 nm. Nanotechnology is referred to as a convergent science because it involves many scientific fields including physics, chemistry, and medicine. The tiny size of nanotechnology makes it susceptible to quantum-based phenomena that can include molecular forces called Van der Waals forces and quantum size effects.

Richard Feynman was the first person to ever conceive of nanotechnology in his book, entitled There’s Plenty of Room at the Bottom, in 1959. He suggested that tools already in use could be developed to be one-tenth the size. In turn, these now smaller tools could be used to create an even smaller set of tools. The size of the tools would continue to get smaller and as they did, some tools would be redesigned to deal with the different forces that it would encounter such as stronger Van der Waals attractions and surface tensions.

The term nanotechnology was created by Norio Taniguchi in 1974 to describe the precision manufacture of materials with nanometer tolerances. In 1986, with the publication of Engines of Creation, Eric Drexler explored the subject in much greater technical depth.

He included computational methods, which are used today to design and simulate molecular systems.

MBE STM system Today, nanotechnology is a very popular area of research. Nanoscaled devices will resemble nature’s nanodevices such as proteins, membranes, and DNA. Atomic force

Scanning tunneling microscope at the Institute of Physics.

microscopes and scanning tunneling microscopes are used to move atoms around to form structures and supramolecular chemistry is now used to design molecules to self-assemble into larger structures. Today, many discoveries are occurring on the nanoscale level and most of these nanotechnological inventions will be able to help miniaturize our world and hopefully will advance our capabilities in many fields and aspects.

Nano-Graphite

BMW’s hydrogen car.

The fuel that we use in our daily lives to run our transportation devices is running low. It is also injurious to our environment because of the emission of greenhouse gases. Using hydrogen to replace fuel is the perfect solution for these problems and it only needs to combine with oxygen to produce energy. Hydrogen cars have already been built but there is still a problem. Storing hydrogen is expensive because it needs heavy, bulky, and expensive to store the hydrogen in extreme cold, heat, or pressure conditions. Government agencies around the world have been funding several research projects in hopes of finding a way to use hydrogen as an alternate source of fuel more efficiently. In 2003, the U.S. announced a five-year $1.2 billion dollar fund devoted to hydrogen fuel research and Shell Oil is spending $1 billion dollars over five years, starting in 2001.

Scientists have currently turned to nanotechnology to solve this problem. Currently, the Steacie Institute for Molecular Sciences in Ottawa and the Technical University of Dresden in Germany has been looking at the chemical interactions between graphite and hydrogen. Their observations show that graphite that is spaced a little less than a nanometer can store hydrogen well at room temperature. More research on this “nano-graphite” still needs to be done but it does look promising.

Nano-Scale Fiber Optics

A recent discovery has been made pertaining to one-dimensional nanoscopic nanowires, which are important for future miniature opto-electronic components. Phospholipids found in membranes of cells which have preferences for cadmium ions are first treated with hydrochloric acid fumes. Cadmium ions from the phospholipids are then forced out of place by the hydrogen from the hydrochloric acid and they travel into the water layer between the membrane layers. The cadmium reacts with the chloride ions from the acid and forms tiny cadmium chloride crystals which grow into one dimensional wires that can get up to 170 µm long and only 100 nm in diameter. These wires can conduct light just like optical fibers.

Wiring the Brain at the Nanoscale

One of these days, doctors may be able to use nanowires that are 100 times thinner than human hair to monitor individual brain cells and provide new treatments for neurological diseases like Parkinson’s. Researchers believe that nanowires can be constructed to be tinier than the smallest capillary vessels in our body which would mean that those nanowires could be spread through the body via the circulatory system without interfering with the body’s mechanisms.

How nanowires can spread to the different parts of the body via the circulatory system.

Today, doctors use arterial paths to guide larger catheter tubes to targets in the body to study blood flow around the heart. If an entire array of nanowires could be guided to the brain through the circulatory system, they could branch out until they reached their locations and could be used to record the electrical activity of single nerve cells or groups of nerve cells.

Scientists speculate that if this is made possible, current technologies like positron emission tomography scans and functional magnetic resonance imaging could reveal much clearer pictures of neural circuits and their processes. Also, doctors would be able to pinpoint damage from strokes and injuries, localize the cause of seizures, and detect tumors and brain abnormalities.

Nano Valves

How the nano valve works.

National Science Foundation has funded a research that has led UCLA chemists to create the first nano valve that can be opened and closed at will to release and trap molecules. This means that molecules can now be controlled on the nanoscale. The nano valve is smaller than living cells and consists of a switchable rotaxane molecule attached to a tiny piece of glass. The glass has tiny pores to let molecules in and out and the switchable rotaxane molecule can move to block the pores using an electron as the energy source to move it.

This new technology has opened the way for scientists to do more research and maybe devise a way to use the nano valve to release drugs inside of cells.

Nanopores

Nanopores are sponges that are so tiny that they are measured in nanometers. They are able to stick to various chemicals and can soak up odors, draw out toxins, and soak up air. The more surface area there is on the nanosponge, the more molecules can stick to it. On nanopores, several thousand meters square can fit on one gram of the sponge.

Nanopores have proven to be a very versatile and useful technological development. By being able to soak up air, it acts as an effective thermal insulation, which can be seen in space shuttles. It may also be the answer to how to store hydrogen as fuel for cars in the future. Nanopores can also enable technology to separate complex fluids and to carry out catalytic reactions.

Another use of the nanopore is that it can act as a cooler by sucking out heat by evaporating water from the sponge. A company called NanoCool™ has already been in business selling temperature-controlled solutions for shipping purposes. Their revolutionary patented technology allows for shipping between 2-8 degrees Celsius and claims that it is great for shipping biotechnology, pharmaceutical, medical, and specialty food shipping. The cooling power is seven times greater than ice and there is a lower weight and cost when compared with ice. It also responds to varying ambient temperatures.

The current market for nanopores is $1.77 billion and the technical market research firm Business Communications Company has expected the price to rise to $2.12 billion by 2012.