The SOFC consists of a cathode, electrolyte and an anode. Oxygen air is led into the cathode where the oxygen is reduced. The fuel (H 2 or CH 4 ) is fed through the anode. Because of the difference in oxygen activity between the cathode and anode, oxygen ions will diffuse through the electrolyte towards the anode. The oxygen ions free two electrons at the anode. The free electrons are then sent back to the cathode through the outer circuit creating a current. The electrons then travel to the cathode, where they reduce oxygen from air, thus continuing the electricity-generating cycle. Cells are combined in series to get a higher voltage or in parallel to get a higher current.
Structure of a (7,1) (single-wall) carbon nanotube looking along the tube axis. The golden spheres represent carbon atoms and the bonds between them are marked by connecting lines. http://www.physnet.uni-hamburg.de/iap/group_s/Fig2.html
carbon nanotube tips AFM tips (CNTs) consist of a single multi-walled carbon nanotube that is welded onto a commercial AFM probe. The CNT is then sharpened, resulting in a tip radius of better than 5 nm. http://www.xintek.com/products/afm/index.htm
Nanotube Field Effect Transistor Nanotubes have been used by IBM and Delft to build a FET, the basic building block of IC design. http://www.rpi.edu/dept/materials/COURSES/NANO/ward/page5.html
Nano Applications NANO 52 Foothill College
The Next Big Thing (only smaller) http://mrsec.wisc.edu/Edetc/cineplex/nanotech.html Live at 5 http://mrsec.wisc.edu/Edetc/cineplex/live5.html Nanotechnology Applications Professor George Lisensky http:// mrsec.wisc.edu/Edetc/cineplex/nanoquest/applications.html
Stained-Glass as Ancient Nanotechnology Stained-glass windows have been around for centuries, but they rely on the same scattering properties of light that modern nano-based colorimetric indicators do.
Nanotechnology Today Current nanotechnology pursuits include the nano-porous filtering compounds known as zeolites, DNA with artificial enhancements, nanoparticle colorimetric agents and nickel nanowire thermal conduction enhancements
Research in Nanotechnology Examples of research are nanotube transistors (upper left), novel quantum structures (lower left) and nanoelectromechanical devices such as the nano-vane on the right.
Medicine Atom Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug-delivery vehicles. 100 µ m 10 µ m 1 µ m 0.1 µ m 0.01 µ m 0.001 µ m (1 nm) Eukaryotic cells Proteins Viruses Bacteria Ribosome Nucleus Gate of Leading Edge Transistor Visible Light Surface Micromachining Features (MEMS) Molecules (10 nm)
Lab on a Chip: Monolithically Integrated µ ChemLab ™ Courtesy of Sandia National Laboratories Biological tests measuring the presence or activity of selected substances become quicker, more sensitive and more flexible when certain nanoscale particles are put to work as tags or labels.
Nanoparticles of cadmium selenide (quantum dots) glow when exposed to ultraviolet light. When injected, they seep into cancer tumors. The surgeon can see the glowing tumor, and use it as a guide for more accurate tumor removal.
Cancer Treatment via Laser Activated Drug Release from Nano Shells. A nanocomposite particle can be constructed so that it has a mix of properties that would not otherwise happen in nature. By combining an organic matrix with metallic clusters that can absorb light, it is possible to incorporate such particles into cells and then destroy those targeted cells with a laser.
Cancer Treatment "nanoparticles" that target specific tumor cells or, as illustrated in this example, the blood vessels that feed them. About the size of a red blood cell, these micron-sized nanoporous mother ships would move through the body, target specific tumor cells or the blood vessels that feed them. After arriving at their destinations, mother ships would release their payload nanoparticles, which could be designed to help image tumors, enter cells and perform measurements, and deliver therapies.
Tissue Engineering Electrospinning and self-assembly are two promising techniques under investigation to fabricate nanodimensional fibres for tissue engineering.
Nano Catalytic Converters The unit is powered by the vehicle's existing 12V battery through the ignition switch. The device consists of nano structure co-axial wave-guide within a microwave dielectric cavity resonator. When the fuels pass through the electronic catalytic converter, the fuel molecules are excited by the microwaves and cold plasma waves from the nano wire arrays. With the waves adiabatically compressed, the fuel molecules undergo conformational changes, viscosity and density changes on account of dipole and ionic conduction phenomenon of the molecules interacting with the electric field component of the microwave. The density, viscosity, activation energy, enthalpy changes of the fuel molecules in real time during flow within the nano structure wave guide improves the fuel quality onboard in real time and changes the chemical rate constant and kinetics of combustion. This results in improved engine performance such as smoother engine as experienced with higher octane fuels or high cetane diesel facilitating reduced emissions and improved fuel economy.
Photocatalytic Air Purifier Pre-filter provides the first cleaning process to remove larger particles, dust mites, hairs or fibers. The TiO2 filter conducts the first disinfection process and slows down the air flow for better particle absorption UV lamp effectively destroys the DNA and RNA of all sort of germs. It also activates the photocatalytic device. Nesting filter design increased the area of photocatalytic disenfection, enabling better performance in removing germs and eliminating stinking air. Producing a forest like ion density. therefore rovides you the most healthy air. 8200V electronic filter absorbs the miniature dust and decomposed particles.
Photocatalytic Coatings The coatings, known as “photocatalytic coatings” are usually applied like a spray paint, are not toxic and are very cost-effective. The photocatalytic coating solutions have been used for years in Japan, where they were originally developed to combat air pollution, infectious microbes and soiling of exterior surfaces. When applied, the treated surface oxidizes contaminants in the presence of light. The result is a self-cleaning surface which will degrade any organic substances such as grease, oil, soot or microbes. The result is that the surface remains clean and attractive, instead of becoming soiled or faded
Fuel Cell Technology A hydrogen fuel cell would bring in hydrogen and oxygen, create electricity to power your vehicle, home, etc, and release water and heat.
The Solid Oxide Fuel Cell An SOFC is a ceramic power generating device. It produces electric power by an electrochemical reaction, and can operate continuously as long as natural gas is supplied to it.
Fuel Cell Technology Hydrogen fuel cells use hydrogen and oxygen gas to create electrical energy. They differ in their internal chemistries but the reaction is always basically the same: hydrogen+oxygen=water , the basic reason for their eco-friendly reputation. Flow plates are used to bring hydrogen gas to one side of the fuel cell while oxygen is brought to the other. A catalyst (usually platinum) breaks the hydrogen gas into positive ions (protons) and electrons. The central membrane, the protron exchange membrane, allows only positive charges to pass through. The positive ions pass through the central membrane while the electrons are stuck and flow away through conductors that provide the electrical current that provides the useful power. Once the positive ions and electrons reach the other side of the fuel cell, where the oxygen is, another catalyst (usually platinum) combines the positive ions, electrons and oxygen yielding water and releasing heat. As long as hydrogen and oxygen continue to be pumped to the fuel cell, the fuel cell can provide electrical energy. Unfortunately, the amount of energy produced by one fuel cell is very small. To make fuel cells more powerful several fuel cells are connected to provide higher voltage and more current. Nanotechnology is helping fuel cells by making them more efficient.
Nano Fuel Cells Nanotechnolgoy will help make fuel cells smaller and more efficient so that they can eventually be used to power everyday portable devices.
Hydrogen Storage Carbon nanotubes covered in titanium atoms provide the most efficient method for storing hydrogen known to date. Despite their small size, they can hold 8% their weight in hydrogen gas. Calculations showed that as many as 4 hydrogen molecules (8 atoms - hydrogen is diatomic) will bond with the titanium atom/carbon complex, meaning these nanotubes can hold 8% their weight in hydrogen gas. The hydrogen is further calculated to release (desorb) easily as diatomic molecular hydrogen when the structure is heated to about 500C. This property makes carbon nanotubes peppered with titanium potentially viable as hydrogen storage matrices.
Nanofiltration One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm. Nanofiltration is mainly used for the removal of ions or the separation of different fluids
Zeolites Suitable materials for hydrogen storage contain a large number of small nanosized pores. Therefore many nanostructured materials like nanotubes, zeolites or alanates are under investigation. It is the porosity of this framework that give rise to the many potential applications of zeolites, including catalysis and molecular sieves. These porous aluminosilicate frameworks can incorporate small molecules or charged species to produce optical compounds such as pigments, for example ultramarine. They are relatively non-toxic and chemically and thermally very stable, which would make zeolite based pigments a promising alternative to some conventional toxic pigments.
The principles of membrane filtration are that the liquid to be filtered passes over the membrane at high velocity. Depending on the membrane pore size, different sizes of molecules are able to pass through the membrane. The feed product is split into two streams: Permeate containing water and particles smaller than the membrane pores. Retentate containing water and particles larger than the membrane pores. Process Membrane filtration enables you to separate particles with a diameter smaller than the pore diameter in the membrane from the liquid feed, by applying a driving force (pressure) over the membrane.
This process, first used in the medical world, has been adapted by researchers at Veolia Water to allow for its use with large volumes of water and for the large scale production of drinking water at prices suited to market demand. Nanofiltration has been used since 2002 in Coliban, Australia, to treat up to 126 million liters of water a day The water treatment plant at Méry-sur-Oise provides the Parisian suburbs (4 million inhabitants) with high quality water thanks to a membrane process developed by researchers at Veolia Water.
Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.
Nano Solar Cells Here's the quote on MIT's Technology Review (July/August 2004), "Breakthroughs in nanotech are making it possible to turn out cheap, flexible solar cells by the meter. Soon your cell phone may be powered by the sun."
Nano Solar Cells Light excites and electron-hole pair in a pn junction that has a voltage difference across it. Carriers are swept out to do useful work. Note that the electron does the traveling outside the
Dye Sensitized nanocrystalline solar cell dye + light dye* dye* + TiO 2 e - (TiO 2 ) + oxidized dye oxidized dye + 3/2 I - dye + ½ I 3 - ½ I 3 - + e - (counter electrode) 3/2 I -
Nano-Batteries A University of Florida research team is developing nano-batteries that could enable smaller, smarter, feature-packed mobile devices, as well as truly tiny power sources for "microelectromechanical" devices (aka MEMS): These batteries are made of composites of small particles. Their ability to produce power depends on lithium ions diffusing throughout these particles. While microscopic, the particles are large enough to be measured in microns, or millionths of a meter. The nano-battery approach seeks to replace these particles with particles measured in billionths of a meter, which would enhance power storage and production because the lithium ions would have less distance to travel as they diffuse.
Photonic Crystals Photonic crystals are materials with a periodic variation in the refractive index with a lattice constant that is half the wavelength of the light used. They offer a selectable band gap for the propagation of a certain wavelength, thus they resemble a semiconductor, but for light or photons instead of electrons.
SEM image of a slab of macroporous silicon, representing atwo-dimensinal Photonic Crystal (a). The pore walls are about 100 µm tall and about 25 µm wide in the direction of transmission (b).Omitting some pores yielded a wave guide structure (c). The extremely smooth finish of the structure is clearly visible (d).
Several types of waveguiding structures SEM images of line defect structures such as bends (a), beamsplitters (b), and resonators (c) in macroporous silicon. These are a few illustrations as to what passive Photonic Crystal-based devices may soon appear as components of commercial products. Possibly even more exciting are the possibilities for active devices.
Quantum Dot Lasers Quantum dot lasers, which use this technology, are revolutionary lasers that are significantly superior to conventional semiconductor lasers in that they feature higher performance in such aspects as temperature-independent operation, low power consumption, long-distance transmission, and high speed.
CNT-FED Carbon nanotubes can be electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.
Quantum Computers The fundamental unit of information (called a quantum bit or qubit), is not binary but rather more abstract in nature. This qubit property arises as a direct consequence of its adherence to the laws of quantum mechanics which differ radically from the laws of classical physics. For example, quantum dots exhibit tunneling phenomena, allowing them to be in more than one place at once (principle of superposition). Engineers know this will allow for parallel processing and computing power that is magnitudes higher than what is currently available.
The new silver nanoparticle Fresh Box super airtight food storage containers can reduce bacteria by as much as 99.9%. It's not a miracle, it's the silver. Your food stay fresher longer so you throw away less. The naturally anti-fungal, anti-bacterial and anti-microbial properties of the finely dispersed nanosilver particles permanently imbedded in the containers will save you money while helping insure you and your family enjoy safer, fresher, healthier, tastier food.
Nano Optics coatings Subwavelength structure size is a key to nano-optics’ optical and physical advantages. Nano-optic elements employ microstructures one or more orders of magnitude smaller than the wavelengths of the incident light — with dimensions typically on the order of 10s to a few 100s of nanometers.
Nano Coating Moen is incorporating hydrophobic nanotechnology, supplied by Diamond-Fusion International, into their new line of luxury faucets and accessories for kitchens and baths. Moen’s Vivid Collection will use the coating to guard against watermarks and deposits. Hydrophobic coatings repel fluids, causing them to gather into spherical beads and roll of surfaces.
Gecko Feet Adhesives The tiny hairs on a gecko’s feet, called setae , enable it to stick to surfaces. This is due to an intermolecular attraction between the setae and the surface, known as Van der Waals forces. A team at the NanoRobotics Lab, Carnegie Mellon University (CMU), has used a dry elastomer adhesive that mimics setae and enables a robot to climb walls and ceilings. However the CMU Waalbot has far greater sticking power because its fibers are twice as adhesive as the setae of geckoes
Stain, wrinkle, and liquid-resistant fabrics Because the chemical is on a “nano-scale”, Nano-Tex Resists Spills fabrics achieve unsurpassed durability without sacrificing the natural hand and breathability of the fabric. Nano-Tex fabric protection is a chemical enhancement, attached at the molecular level, to fundamentally transform the fibers.
Clothing which can absorb body odors NanoHorizons, based in State College, Pa., has begun to sell a line of metallic nanoparticles that are compatible with standard polymer manufacturing process. This means that silver, gold and other metals that kill bacteria and odor-causing microbes can be incorporated into shoes, athletic equipment and other plastic or nylon products.
New Silver Bandages May Help Heal Wounds Silver reduces the growth of hundreds of types of bacteria responsible for wound infection
Clothing that changes color University of Pittsburgh researchers have synthesized a molecule that forms the first "nanocarpet," whereby the nanotubes organize themselves into an expanse of upright clusters that looks like the fibers of a shag rug. Moreover, unlike other nanotube structures, these tubes can sense their environment, change color and can be trained to kill bacteria. The research aims at developing a paint that in the event of biological or chemical agents being deployed would change color and simultaneously destroy the deadly substances.
Cosmetics Molecule-level nanotechnology has been applied for moisturizers to penetrate deep into the skin and to create baby-like suppleness from the inside. Contains hyaluronic acid derivative (moisturizer).
Nano Sunscreen Nanoparticles of Zinc Oxide or Titanium Oxide are used to make sunscreen invisible (Image: iStockphoto)
Nano Paint Nanoparticles are used to make paints and varnishes that give long-lasting UV protection (Image: iStockphoto)
Carbon Nanotube/Cement Composite Systems In concrete, they increase the tensile strength, and halt crack propagation.
Sports Equipment CNT Carbon Nanotube technology enhances Easton's unique Opti-Flex composite handle technology, providing maximum handle flex-three times greater than aluminum in the case of the BST6 Stealth Regular Flex
'Artificial muscles' made from nanotubes "Artificial muscles" have been made from millions of carbon nanotubes. Like natural muscles, providing an electrical charge causes the individual fibres to expand and the whole structure to move. However, any application of this work in replacing biological muscles is "nearer the dream factory than reality". The real benefit of the breakthrough may come in generating energy from ocean waves.
Bucky Paper A sample of "bucky paper," a super-strong material developed through nanotechnology by university engineers. A thin sheet made from nanotubes that are 250 times stronger than steel and 10 times lighter that could be used as a heat sink for chipboards, a backlight for LCD screens or as a faraday cage to protect electrical devices/aeroplanes
chemical nanowires Carbon nanotubes additionally can also be used to produce nanowires of other chemicals, such as gold or zinc oxide. These nanowires in turn can be used to cast nanotubes of other chemicals, such as gallium nitride. These can have very different properties from CNTs - for example, gallium nitride nanotubes are hydrophilic, while CNTs are hydrophobic, giving them possible uses in organic chemistry that CNTs could not be used for. Below is a picture of a junction between a gold nanowire (top) and a carbon nanotube (Credit: Fung Suong Ou, RPI).
CNT light bulb filament : alternative to tungsten filaments in incandescent lamps
Nano SQUID A SQUID is a superconducting interferometer device. SQUID devices can be used to monitor infinitesimally small magnetic fields or currents. The originality of this work, is to use gate-tunable carbon-nanotubes (CNT) for the Josephson junctions. The device combines features of single electron transistors with typical properties of a SQUID interferometer. The gate tunability of the CNT junctions enhance the sensitivity of the device which can in principle detect the spin of a single molecule.