Presentation on theme: "NANOTECHNOLOGY INPUTS, PROCESSES, FORMS, AND PRODUCTS."— Presentation transcript:
NANOTECHNOLOGY INPUTS, PROCESSES, FORMS, AND PRODUCTS
TABLE OF CONTENTS SLIDE 1 – COVER SLIDE 2 – TABLE OF CONTENTS SLIDE 3 – INTRODUCTION TO REPORT SLIDE 4 – A NOTE REGARDING THE RESEARCH METHOD SLIDE 5 – INTRODUCTION TO INPUTS SLIDE 6 – CARBON ATOM PROPERTIES SLIDE 7 – CARBON ATOM APPLICATIONS SLIDE 8 – GOLD ATOM PROPERTIES SLIDE 9 - GOLD ATOM APPLICATIONS SLIDE 10 - ALUMINUM ATOM PROPERTIES SLIDE 11 - ALUMINUM ATOM APPLICATIONS SLIDE 12 – TITANIUM ATOM PROPERTIES SLIDE 13 – TITANIUM ATOM APPLICATIONS SLIDE 14 – OXYGEN ATOM PROPERTIES SLIDE 15 – OXYGEN ATOM APPLICATIONS SLIDE 16 – SILVER ATOM PROPERTIES SLIDE 17 – SILVER ATOM APPLICATIONS SLIDE 18 – ZINC ATOM PROPERTIES SLIDE 19 – ZINC ATOM APPLICATIONS SLIDE 20 – MANGANESE ATOM PROPERTIES SLIDE 21 – MANGANESE ATOM APPLICATIONS SLIDE 22 – CALCIUM ATOM PROPERTIES SLIDE 23 – CALCIUM ATOM APPLICATIONS SLIDE 24 – HYDROGEN ATOM PROPERTIES SLIDES _ THROUGH _ - BIBLIOGRAPHY
INTRODUCTION TO REPORT This report on Nanotechnology: Inputs, Processes, Forms and Products, is intended to introduce the reader or audience member to the growing field of nanotechnology. This report will cover four topics within nanotechnology. Those are Inputs, Processes, Forms, and Products. The Inputs are atomic elements and the machines that manipulate them. The Processes are the acts of manipulation themselves. The Forms are the immediate output from these processes. The Products are the end-use services and devices that will demonstrate what is possible due to these advancements. The report will start with a survey of commonly used atomic elements, but will ultimately focus on the elements that have proven most useful to aerospace applications. Whereas much literature focuses on investing opportunities, or the pure science of nanotechnology, this report will restrict itself to aerospace applications. However, this report does not assume a general knowledge of nanotechnology on the part of the reader or audience member. A wide introduction to nanotechnology, with its many inputs, processes, forms, and products, will be necessary to understand what is possible.
A NOTE REGARDING THE RESEARCH METHOD The most common research tool for this report was the Internet, with Google being the starting point. As anyone who has done research on the Internet should well know, verification of information, and knowing for certain that what one is reading is correct, is a challenge. Knowing this, and having spent over half of my college education with Google as a tool, I've only used this search engine as a means to find sources that I doubt many people would have issues with. All sources are noted in the Bibliography. Web sources have the URL and date accessed. I humbly submit this report knowing full well that I am not scientist in this field, and have great respect those whose work I've cited.
INTRODUCTION TO INPUTS Inputs are the first topic that will be presented. Inputs include both atomic elements and the machines that researchers and industrialists use. Among the atomic elements that exist, I have focused among the most commonly used elements in this field. Those are carbon, gold, aluminum, titanium, oxygen, silver, zinc, manganese, calcium, and hydrogen. Typical machines used in nanotechnology are the atomic force microscope, the scanning tunneling microscope, chemical vapor deposition device, molecular beam epitaxy machine, lithography tools, diffraction tools, scanning electron microscope, the transmission electron microscope, and the near-field scanning optical microscope. Netoholic Kristian Molhave
CARBON ATOM PROPERTIES The carbon atom is one of the most studied atoms in the world. It has a whole field of chemistry devoted to it – organic chemistry. Carbon exists in more compounds than any other element 1. Carbon forms stable bonds with other atoms, including other carbon atoms, with its four outer-shell electrons 2. These stable bonds are called covalent bonds. Often mined in coal, carbon usually exists in three different kinds of structures. These are called allotropes. The three allotropes are amorphous, graphite, and diamond 3. A fourth, recently discovered allotrope, is known as the buckminsterfullerene, also known as C Its name comes from the allotrope's resemblance to the architecture of Buckminster. The C 60 allotrope has 60 atoms arranged to form its shape. Saperaud Lee Kwok-san and Tong Shiu-sing Oak Ridge National Laboratory
CARBON ATOM APPLICATIONS Most research regarding carbon and nanotechnology has been the development and refinement of the carbon nanotube 5. The nanotube is a variant on the bucky ball, and retains the same chemical bonding pattern. Among its abilities are superior tensile strength and electrical conduction. It can even substitute silicon for use in semiconductors 6. There would seem to be no limit to what the nanotube can do at its scale. Nanotubes have been proposed as a means to store hydrogen. The weight ratio of carbon to hydrogen is twelve-to-one, which suggests a hydrogen storage capacity of 7.7% by weight 7. Carbon atoms use only three of their outer orbital electrons to bond with other carbon atoms, to form the nanotube 8. That leaves one free electron to bond with hydrogen. Timmymiller (both)
GOLD ATOM PROPERTIES No metal is more malleable or ductile than gold. It can also retain its shape and maintain its appearance longer than many other metals, which helps to explain in historical value 9. Gold forms different bonds from that of carbon. It forms metallic bonds 10. There are so many electrons that they are exchanged easily with other metal element atoms 11. This phenomenon of electron exchange makes metals such as gold excellent conductors of electricity. Gold exists naturally in an unadulterated state 12, and can be sorted from sands and gravel through a process known as panning. Its pure state is so soft that to add strength, gold is alloyed with other elements 13. Gold can be plated onto particles, and can covert light into heat. This has proven useful as a cancer treatment in tests conducted at Rice University 14. Gold's biological inertness contributed to its usefulness. USGS Greg Robson
GOLD ATOM APPLICATIONS Gold nanoparticles have been shown to be effective for both detecting and treating cancer 15. Researchers at Georgia Tech University determined that “absorption and scattering of electromagnetic radiation” is enhanced with the use of noble metals such as gold. This is possible because at the nanoscale, noble metals can increase their absorption of visible-to-ultraviolet light 16. Gold nanoparticles can be bound to antibodies which then attach themselves to malignant cancer cells 17. In this particular example, light near the infrared spectrum is used to locate the nanoparticles. Continuous exposure to a red laser can destroy the malignant cancer cells 18. The benefits of laser therapy and gold nanoparticles for the treatment of cancer are localized damage to the cancer cells themselves (leaving other, desirable cells unharmed), the biological inertness and stability of gold, and gold’s absorptive properties 19. Georgia Tech (both)
ALUMINUM ATOM PROPERTIES Aluminum is a common metal found on Earth. However, unlike gold, aluminum is rarely found unadulterated. Aluminum occurs most often naturally in a compound known as bauxite 20. Aluminum does not form bonds like carbon. Even though aluminum has three outer shell electrons, it does not seek to acquire five more electrons necessary for a closed shell 21. Most of its compounds only acquire three electrons. Aluminum does not rust like iron does, because the byproduct of oxidation, alumina, adheres readily to the aluminum surface 22. However, the byproduct of oxidation of iron does not adhere to the iron surface. Aluminum’s low melting point (1220˚F, or 660˚C) makes it simple to recycle. Extracting aluminum from alumina requires more energy, by comparison 23. USGS
ALUMINUM ATOM APPLICATIONS Researchers at Argonne National Laboratory are interested in aluminum nanoparticles for propellants and hydrogen storage 24. Current research emphasizes making stable, non- agglomerating aluminum nanoparticles. The increase in surface area as the size of the particles decrease means that greater amounts of hydrogen can be stored. For years, anodizing aluminum in sulphuric acid has resulted in a nanoporus coating, which prevents corrosion 25. This material has been applied to the architectural and decorative markets. Stable cellular aluminum has been patented by Austria-based Metcomb 26. Cellular aluminum has the primary advantage of being able to absorb impacts 27. It has a regular structure that contains air bubbles, whose surface walls are coated with an oxide skin, which is a byproduct of the gas from the company's patented process. The NEST Laboratory – University of Dayton Cellular Solids Research Group - MIT
TITANIUM ATOM PROPERTIES Titanium is a common element found not only on Earth, but also on the Moon 29. It is found in igneous (resulting from lava) rocks, iron ore, plants, and in humans. Pure titanium does not occur naturally. It burns in air, and is the only element that burns in nitrogen. It is also resistant to many kinds of acids and solutions, and like gold, is inert in humans 30. Also like gold, titanium is part of the metallic group of elements. Titanium bonds with other metallic elements by sharing electrons freely. However, titanium does not conduct electricity as well as gold does 31. Electrical conductivity results from the ability of electrons to move between two orbitals of a given atomic element, the valence orbital and the conductive orbital. The amount of energy required for electrons to move between these two orbitals must be very small 32. Amethyst Galleries' Mineral Gallery
TITANIUM ATOM APPLICATIONS Titanium nanotechnological applications have seen broad market and scientific uses. Titanium has been studied for use as orthopedic implants 33. The titanium promotes bone-forming cell cohesion by mimicing the nanostructure surface topography of the original bone. The titanium was chemically modified to create the desired topography. Titanium dioxide (TiO 2 ) has been used to separate proteins for analysis 34. TiO 2 creates hydroxyl radicals when exposed to UV light. Hydroxyl radicals are short-lived, so the use of the UV light controls the protein separation process. Titanium and TiO 2 have been used in sun screen, wood protection, paint additives with protective or aesthetic qualities, and to break down nitrous oxides that cars and power plants emit 35. Lifecore Biomedical Germes Online
OXYGEN ATOM PROPERTIES Oxygen is a gas at room temperature, and is essential for plant and animal life. The oxygen molecules that we breath are O 2, whose oxygen atoms are bonded together with a double bond 36. A double bond between two atoms is the sharing of two pairs of electrons 37. Oxygen atoms exist in four allotropes: atomic oxygen, oxygen molecules (what we breath), ozone, and tetraoxygen 38. Atomic oxygen does not exist on earth, but it does in space. It causes damage to spacecraft to oxygen's high reactivity. Ozone is O 3. It exists in the atmosphere as a by-product of the sun's energy acting upon O 2. Tetraoxygen (O 4 ) is a recent discovery, and so far only exists as a laboratory product. Oracle ThinkQuest Crosstek
OXYGEN ATOM APPLICATIONS Oyxgen, due to its low boiling point temperature, is often paired with other elements when used in nanotechnology. Otherwise, loose oxygen atoms tend to form either O 2 or O 3. Oxygen has been used to convert hydrocarbons (molecules that contain hydrogen and carbon atoms) into organic compounds, which contain oxygen molecules 39. Oyxgen may also be used for molecular switches 40. The atom would act as a rotor, which would turn in response to electric charges 41. The switch can be turned (written) to an on-position or an off-position, and also be detected (read) 42. It is the writing and reading of switches at on/off positions that establishes the basis of electronic computing. With molecular switches, electronic computing can continue its quickly increasing speeds and storage capacities. Hewlett-Packard Laboratories
SILVER ATOM PROPERTIES Silver and gold are similar. Both conduct heat and electricity very well 43 and bond metallically. However, there are important differences. Silver does react biologically, though only when consumed in very large amounts 44. Some individuals may experience contact allergies, while others after extensive exposure may develop permanent discoloration of the eyes and skin 45. The EPA regulates the concentration of silver in drinking water 46. Silver has many alloys, and has found extensive use in several industries. Alloys have been used in photographic film development, batteries, as well as dental fillings. When polished, silver is the best reflector of visible light, though it reflects UV light poorly 47. Stirling Silver Jewelery 4 You SilverMedicine.org
SILVER ATOM APPLICATIONS Silver is sold as having same or similar positive health affects at the nanoscale as it does at larger scales 48. The element works as an antimicrobial agent 49. Silver removes chemical compounds from the larger cell against which the silver is supposed to kill 50. Silver's affects have been incorporated into clothing to kill bacteria and other deleterious microorganisms 51. There exists a potential for coatings, that have silver nanoparticles, to be applied to surfaces that the public regularly touches, such as hospital furniture, hand rails, and mass transit vehicles 52. Researchers at the Korean Research Institute of Bioscience and Biotechnology (KRIBB) have demonstrated a method to convert silver nanoparticles into gold nanoparticles 53. The potential health treatment of gold nanoparticles have already been discussed. IoP Publishing JR Nanotech, PLC
ZINC ATOM PROPERTIES Zinc is a common element found on Earth, and is present in foods and water 54. It is also sold as a supplement. There are relatively minor negative health affects due to overconsumption of zinc 55. Zinc is the first element discussed so far that exhibits a property called superplasticity 56. Superplasticity is the ability to stretch or deform without breaking. It is commonly added to alloys to enhance their ability to molded into desired shapes 57. Zinc is a metal 58. Therefore, it conducts electricity, but not as well as other metal elements 59. However, it also reacts with oxygen and other non-metals, as well as acids 60. Like silver, zinc is touted as having many positive health affects 61. Whereas silver has specific antimicrobial uses, zinc consumption affects many areas on the human body, being linked to many improvements and preventative treatments 62. Superb HerbsKobelco
ZINC ATOM APPLICATIONS Zinc oxide has been researched for its electrical conductive properties at the nanoscale 63. Zinc oxide nanowires and nanobelts have been manipulated to create simple electrical components such as transistors, diodes and sensors 64. The zinc oxide nanocomponents demonstrate semiconducting and piezoelectric properties 65. When a material demonstrates piezoelectric phenomena by changing its dimensions 66. An electric charge results in a mechanical change. The opposite is also true 67. Mechanical change results in an electrical charge. Zinc nanocages have the ability to store hydrogen 68. The zinc is arranged with oxygen to form a metal-organic framework 69. Hydrogen storage efficiency can be as high as 10% of the weight of the nanocage 70. T. Yildirim/NIST Georgia Institute of Technology
MANGANESE ATOM PROPERTIES Manganese occurs naturally adulterated with other elements 71, much like aluminun. Also like aluminum, it is often alloyed with other metals 72. Whereas aluminum adds flexibility and ductility to metals, manganese adds toughness, hardness, and stiffness 73. It is quite reactive, and will dissolve in water 74. It is an added component to explosive material 75. It also reacts biologically 76. It is essential to human health 77, and overconsumption from natural sources is difficult 78. However, it is a regulated element when in use in laboratories. Its presence in drinking water is also regulated. When consumed in very high amounts in mining, industrial, or field-use environments, it can create a chronic neurological disorder known as manganism 79. International Manganese Institute Yinon Bentor
MANGANESE ATOM APPLICATIONS Manganese can be used to clean air of volatile organic compounds (VOCs) 80. Gold nanoparticles are sprayed onto a manganese oxide, and together they allow compounds to adhere to the surface 81. The compounds then break down, cleaning the air. Manganese is part of chain of elements including calcium and oxygen that make up a cluster that breaks down water into its component parts – hydrogen and oxygen 82. Researchers in Germany have found the geometric arrangement of manganese, calcium, and oxygen that promotes the breakdown of water. The goal is to enable hydrogen production with the manganese- calcium-oxygen cluster, water, and sunlight 83. Manganese oxide has been used to build nanotubes 84. The potential applications for this kind of nanotube include more efficient fuel cells and cathodes 85. Nature Sinha, et al.
CALCIUM ATOM PROPERTIES Calcium is a metallic element 86, like most of the elements discussed so far. Also like aluminum and manganese, is does not occur in nature by itself. It is often found in limestone and gypsum deposits. Despite being one of the most abundant metals, its highly reactive nature delayed its discovery as a single element 87. Calcium is a well-known element, existing either naturally in many foods, or as an additive or supplement. It is the most common mineral in the human body, and is found predominantly in teeth and bones 88. Overconsumption of calcium from diet and supplements is very uncommon 89. When exposed to air, calcium attracts oxygen and nitrogen to form a protective coating 90. Calcium exposed to water reacts to produce calcium hydroxide plus hydrogen 91. At least one university (Ohio State in Columbus) is researching ways to refine the hydrogen production process using calcium compounds 92. University of Washington
CALCIUM ATOM APPLICATIONS Calcium carbonate nanoparticles have been shown to deliver drugs for the treatment of cancer 93. Two different calcium compounds are stirred together with drug to create nanoparticles containing the calcium compound and drug 94. The nanoparticle has been demonstrated to be stable for up to a week inside the body. Calcium carbonate composite nanofibers have been studied for use in guided bone reconstruction membranes 95. Results have been positive for cell attachment to the membrane 96. Calcium carbonate is also used as a bone-filling material itself 97. Calcium phosphate nanoparticles have been shown to be effective gene carriers 98. Until recently, DNA would degrade before it could have an affect upon the cancer cell 99. The calcium and the phosphorous need to be carefully balanced in order for their nanoparticle to function correctly. Netzsch Feinmahltechnik Fujihara, et al.
HYDROGEN ATOM PROPERTIES Hydrogen is the most common element in the universe, and has one of the simplest atomic structures. It consists of one electron in orbit around one proton 100, making it the smallest atomic element. Hydrogen's light weight keeps it from remaining in the earth's atmosphere 101. Hydrogen occurs mostly on earth in water 102. Therefore, it occurs in all plants, animals and humans. It also occurs in hydrocarbons, which makes up fossil fuels. Hydrogen occurs not only in compounds, but in distinct forms and isotopes. All elements have isotopes, but hydrogen presents the opportunity to explain them the simplest way possible. All atoms have a fixed amount of protons, which are bound to neutrons, at the center of the atom 103. While the number of protons does not change for a given element, the number of neutrons can change 104. The isotopes of hydrogen are proving useful. MSN Encarta Dr. Rita Maria Sambruna
HYDROGEN ATOM APPLICATIONS Hydrogen's role in nanotechnology is mostly that of a byproduct, rather than an actual nanoparticle affecting change at the nanoscale. Much research focuses on extracting hydrogen from other compounds. Hydrogen can be extracted from ammonia, which is NH A metal iridium surface can have a finely textured surface to which ammonia particle adhere 106. The surface permits the breakdown of ammonia, releasing nitrogen and hydrogen gases. Hydrogen can be stored in nanotubes, though a French research team has found that storing hydrogen on carbon nanohorns may be more effective 107. The team found the nanohorns to be more stable than nanotubes, because hydrogen the bonding strength between the nanohorns is greater than that of the nanotubes 108. The problem with all current technologies is that storage methods are too expensive and/or do not meet expected benchmarks. moleculartorch.com CNRS
HOW THE ATOMIC FORCE MICROSCOPE (AFM)WORKS Atomic force microscopy is a type of scanning probe technique 109. Scanning probe microscopes are used to measure distances at the micro-scale and smaller 110. These microscopes use a cantilever- mounted tip which scans across a material surface, and the distance at which the tip moves vertically as it scans is measured 111. The resolution of the AFM extends down to 10 picometers 112 (one trillionth of a meter). The resolution detail is controlled by the conditions in which the AFM is used, such as use in a vacuum chamber and ambient temperature (lower is better) 113. There exists different methods of detecting cantilever deflection. One method is to use a laser to focus light onto a mirror which is placed on top of the cantilever 114. The mirror reflects the light to a position sensitive detector (PSD) 115. Phase-sensitive detection measures the output from the PSD 116. Binnig, et al. Meyer, Gehard and Amer, Nabil M.
HOW THE AFM IS USED The AFM is used to study a wide range of properties for many materials. “The materials being investigating include thin and thick film coatings, ceramics, composites, glasses, synthetic and biological membranes, metals, polymers, and semiconductors. The AFM is being applied to studies of phenomena such as abrasion, adhesion, cleaning, corrosion, etching, friction, lubrication, plating, and polishing” 117. AFMs operate in three modes: contact, non- contact, and tapping mode 118. Contact mode has a DC feedback amplifier controlling the distance between the sample to be analyzed, and the cantilever 119. The tip makes physical contact with surface in this mode. Non-contact mode images surfaces by detecting the forces that attract the tip 120. Tapping mode has the cantilever oscillate, having the tip come into contact with the sample quickly and repeatedly 121. Of the three methods, contact is the most common, followed by tapping and non- contact 122. Austrian Academy of Sciences Swiss Federal Institute of Technology Zurich
HOW THE SCANNING TUNNELING MICROSCOPE (STM)WORKS The scanning tunnelling microscope is the ancestor of the AFM. STM “measures a weak electrical current flowing between tip and sample as they are held a very distance apart” 123. The use of this kind of microscope is limited to materials that can conduct electricity 124. Electrically conductive elements have a large cloud of electrons that surround the nucleous, relative to non-conductive elements. The STM has a tip like the AFM, only the STM's tip does not come into direct contact with the examined material. Instead, when brought close to the material, an electric current can flow between the material and the tip due to the interaction of electrons between the tip and the material 125. An image of the material is produced by measuring the amount of vertical displacement needed to keep the current constant 126. Binnig, et al. Gold, measured with an STM.
HOW THE STM IS USED The inventions of the Scanning Tunneling Microscope and the Atomic Force Microscope opened up a new way of observing and controlling matter at the atomic scale 127. Both machines are used concurrently 128. The STM allowed researchers to learn more about the function of semiconductors, and how different metals react, at the atomic scale, when they are juxtaposed 129. The STM can also manipulate the placement of atoms. The tip of the STM moves atoms by having it be positioned over the atom to be moved, and having the electric current match the adsorptive strength of the overall sample material 130. The atom can then be guided to a new position without the atom detaching fully from the surface material. While current positioning is done either manually or with computer assistance, the National Institute of Standards and Technology is working on an Automated Atomic Assembler 131. Crommie Group, Lawrence Berkeley National Laboratory
HOW CHEMICAL VAPOR DEPOSITION (CVD) WORKS Chemical Vapor Deposition (CVD) converts gaseous material into a solid and deposits it onto another solid 132. A gas delivery system moves the gaseous material, known as the precursor, to the reactor chamber, where it is deposited upon the substrate 133. An energy source is needed to provide heat for deposition to occur, and a vacuum and exhaust system to vent out the extraneous gaseous molecules 134. CVD belongs to a class of a vapor deposition techniques, including molecular beam epitaxy (MBE), that deposits one material atomically upon another 135. Like the previously discusses microscopy techniques, they can be used in conjunction. Some processes are hybrids of two different systems 136. CVD is unique in its ability to “deposit any element or compound”, and do so with very high purity, density, uniformity, economically, and below the material's melting point 137. Michigan Tech Yap Lab Dual-RF-plasma CVD System Thermal Chemical Vapor Deposition CVD System
HOW CVD IS USED CVD is used in the manufacture of artificial diamond 138. The diamond “is comparable in purity and properties to...natural diamond. The hardness of diamond, coupled with the conformality of CVD films, can be exploited to make tool coatings and inserts with long cutting lives” 139. A new method of CVD has been demonstrated to collect and distribute atoms along a specific path 140. The method is plasmon-assisted CVD, which differs from convetional CVD by use of a low-powered laser beam 141. “The technique makes use of the plasmon resonance in nanoscale metal structures to produce the local heating necessary to initiate deposition...” 142. Thermal CVD has been used to grow carbon nanotubes 143. The growing process requires depositing Iron, Nickel, Cobalt, or an alloy of the three metals onto a substrate 144. The substrate is etched, placed into the thermal CVD apparatus, etched again, and heated to produce carbon nanotubes 145. Boyd, et al.
HOW MOLECULAR BEAM EPITAXY (MBE) WORKS When “atoms are deposited on a substrate and continue the same crystal structure as the substrate ”146, this is called epitaxial growth. “Molecular beam epitaxy (MBE) is a term used denote epitaxial growth of compound semiconductor films by a process involving the reaction of one or more thermal molecular beams with a crystalline surface under ultra-high vacuum conditions” 147. Molecular beams are typically generated by thermally evaporating elements, although other sources are used 148. MBE requires an ultra-high vacuum (UHV) environment 149. MBE systems include a vacuum system, a pumping system, liquid N 2 panels, effusion cells, a substrate manipulator and analysis tools 150. “The pumping system usually consists of ion pumps” 151, which attract gas molecules due to the lower pressure maintained within the pump 152. Effusion cells are where the element is thermally evaporated 153. Dr. Werner Wegsheider Institute of Semiconductor and Solid State Physics Austria
HOW MBE IS USED MBE is used in conjunction with other tools. It has been used to create quantum dots 154, which belong to the semiconducting group of materials 155. MBE has also been used to grow Gallium Nitride (GaN) quantum discs and Aluminum Gallium Nitride (AlGaN) nanocolumns 156, which may have applications for optoelectronic devices. Such devices include lasers and light- emitting diodes (LEDs). GaN nanodiscs and AlGaN nanocolumns create lattice structures free of “atomic-scale defects, called dislocations” 157. These dislocations have limited the spectral range of lasers, ranging between near-UV and green 158. MBE has also been used to grow Germanium (Ge) quantum dots 159. These have been grown on silicon, and potential applications include not only optoelectronics, but also “resonant tunneling diodes, thermoelectric cooler, cellular automata, and quantum computer[s]” 160. Sarikaya, et al. Gallium Indium Arsenide (GaInAs) Quantum Dots Bertness, et al. Cross-Section and Top View of GaN nanocolumns (or nanowires)
HOW LITHOGRAPHY FOR NANOTECHNOLOGY WORKS Lithographic tools are used to mass produce microchips and other semiconductor devices 160. Lithography works by layering a material sensitive to light (or whatever will do the etching) upon a substrate, and exposing the sensitive material to a controlled light, etc, pattern 161. At the nanoscale, lithography has been used to pattern a “substrate for selective growth of nanostructures” 162. One example of lithography used was in the production of arrays of silver and gold- palladium nanoparticles 163. These particles were created with a scanning transmission electron microscope (STEM). The STEM focused a 2 nanometer-diameter electron beam to create the pattern 164. Another example is transmission electron beam ablation lithography, which works by “controllably ablating [removing by melting] evaporated metal films, pre-patterned with electron beam lithography” 165. MEMS and Nanotechnology Clearinghouse
HOW LITHOGRAPHY FOR NANOTECHNOLOGY IS USED EV Group Australia and Komag, Inc., have partnered up to use nanoimprint lithography (NIL) to create discrete track recording (DTR) patterned magnetic disks 166. NIL works by pressing molds “into a thin thermoplastic polymer film on a substrate that is heated above its glass transition temperature” 167. This method allows for greater production quantities. Hot embossing imprint lithography has been used to form mechanical topography on polymer cell substrates 168. These substrates are on the surface of joint replacements, biosensors, and drug delivery devices. The topography of these substrates can influence how well the body's cells adhere to the implant which uses the substrate. Nanoparticle self-assembly has been demonstrated with chemical lithography 169. “[P]article arrangement is controlled by differences in reactivity – a characteristic determined by exposing particles and surfaces to an assortment of chemical treatments” 170. Chou, et al.
HOW SCANNING ELECTRON MICROSCOPES WORK Scanning electron microscopes (SEMs) generate images based on the deflection of beamed electrons off a given sample 171. An electron gun, consisting of a cathode and an anode, generate the beam by attracting electrons from the cathode to the anode 172. The beam is focused using an objective lens 173. What makes SEMs useful is their superior magnifying capability. Optical microscopes use visible light, whose wavelength ranges from 400 to 700 nanometers 174. The wavelength of an electron varies depending on its momentum, and can be quite smaller than that of visible light 175. This means that electrons that deflect off the sample do so at a lower wavelength than that of visible light, thus permitting greater resolution than what an optical microscope can provide. The sample information that SEMs can provide include topographical, atomic number, thickness, and composition information 176. Material Science and Engineering Department at Iowa State University
HOW SCANNING ELECTRON MICROSCOPES ARE USED Manipulators can operate inside an SEM, allowing real-time imaging of an experiment in progress 177. The actual device that performs the manipulation is called an end- effector, and can include “[s]harpened metal wires, referred to as probes” 178, AFM tips (also known as cantilevered probes), and microelectromechanical systems (MEMS)- based grippers 179. These manipulators can work with focused ion beam (FIB) systems to perform failure analyses of semiconductor devices 180. An example of an end-effector in use was in an SEM, armed with a cantilever manipulator with a force sensor tip 181. The equipment was used to test the tensile properties of carbon nanotubes 182. The SEM introduced hydrocarbon contamination to attach the nanotube to the sensor tip, in a process known as nano-welding 183. Seung Hoon Nahm
INTRODUCTION TO FORMS Forms are the second topic that will be presented. Nano-sized creations can come in four dimensional forms: the 0 th dimension (nanoparticles), the 1 st dimension (nanowire or nanotube), the 2 nd dimension (nanofilm or nanosheet), and the 3 rd dimension (nanomachine). While the nanotube is three-dimensional (having diameter and length), it is useful to differentiate its form from that of more complex three-dimensional organizations. From an architectural reference, thinking of these dimensional forms in terms of point, line, plane, and mass respectively may be helpful. The properties and applications of these forms are varied and many. What elements are used, and in what manner of configuration, influence the nature of these forms. I will introduce examples to illustrate only that differences do exist among forms. Univerity of Southern California Nanofilm Surface Analysis C’Nano Rhône-Alpes Brent Silby
THE PROPERTIES OF 0-DIMENSIONAL NANOFORMS The nanoparticle label can be said to be a valid description of a given particle when that particle's effects are dominated by the rules of quantum mechanics 184. The science of quantum mechanics describes the behavior and function of light and particles at their most discrete. What this means is that for nanoparticles, the effects of atomic behavior dominate the surface of particle, rather than its interior 185. These particles can be engineered to have specific properties, “often accomplished by coating or encapsulating them within a shell of a preferred material… For example, the shell can alter the charge, functionality, and reactivity of the surface, and can enhance the stability and dispersibility of the colloidal [consisting of two different phases -- solid, liquid, etc] core. Magnetic, optical, or catalytic functions may be readily imparted to the dispersed colloidal matter depending on the properties of the coating.” 186. Matthew Meineke
APPLICATIONS OF 0-DIMENSIONAL NANOFORMS The market for applications using nanoparticles has been realized 187. Industry size was expected to be worth $900 million by 2005, with an average annual growth rate of 12.8% for the period between 2000 and One example of nanoparticle applications are molecular tags 189. The applications of gold nanoparticles, for cancer detection and treatment, were discussed earlier. Also discussed were the applications of aluminum nanoparticles for hydrogen storage. Magnetite nanoparticles have been proposed for use in molecular/nanoelectromechanical systems (MEMS/NEMS) 190. These particles can be magnetized, placed into traps surrounded by conductors, and subjected to an electrical field. They then rotate, permitting mechanical power at a larger scale. Georgia Tech The NEST Laboratory – University of Dayton
PROPERTIES OF 1-DIMENSIONAL NANOFORMS Nanotubes and nanowires are two kinds of one-dimensional nanoforms. The names are suggestive; nanotubes have a hollow interior, while nanowires do not. The nanotube has gotten considerable press for its properties. Tests have demonstrated the stiffness of carbon nanotubes to extend up to 673 Gigapascals (GPa) or psi 191. They “combine high stiffness with resilience and the ability to buckle and collapse in a reversible manner: even largely distorted configurations (axially compressed or twisted) can be due to elastic deformations with virtually no atomic defects involved.” 192 Nanowires have demonstrated interesting electromagnetic properties. For example, giant magnetoresistance (GMR) has been “observed at room temperature on [Cobalt/Copper] multilayered nanowires.” 193 GMR “is the phenomenon where [electrical] resistance in certain materials drops dramatically when a magnetic field is applied.” 194 Future Hi L. Piraux, et al.
APPLICATIONS OF 1-DIMENSIONAL NANOFORMS As mentioned earlier, there appears to be no limit as to the number of applications that the nanotube can perform. Structural and electrical properties have already been mentioned. The carbon nanotube can also “produce streams of electrons very efficiently (field emission), which can be used to create light in displays in televisions or computers, or even in domestic lighting, and they can enhance the fluorescence of materials they are close to.” 195 Nanowires (or nanofibers) have been studied for low-temperature electrical discharge, for use in lithium-ion batteries (the kind used in laptops and cell phones). 196 The high surface area-to-volume ratio helps to “mitigate the slow electrochemical kinetics problem”. 197 The slow kinetics problem is the decrease in charge delivered from the battery at low temperatures 198. Erkki Halkka - ESA
PROPERTIES OF 2-DIMENSIONAL NANOFORMS Two-dimensional nanoforms can come in nanofilms or nanoplates. Like the carbon nanotube, they can display remarkable properties. A nanofilm, a nanomembrane, has been developed that can hold up to 70,000 times its weight in water, can pass through a hole 30,000 times smaller than the membrane itself, and be as large as 16 square centimeters. 199 Its properties came from the way it was manufactured. The membrane is a hybrid of organic polymers with inorganic components 200 within an interpenetrating network 201. An interpenetrating network is “any material containing two polymers, each in network form.” 202 Zinc Oxide nanoplates have been shown to have a relatively large “surface area for heat dissipation and large field enhancement factors”. 203 A large field enhancement factor lowers the threshold for electron emission. Vendamme, et al.
APPLICATIONS OF 2-DIMENSIONAL NANOFORMS Nanofilm applications have already been capitalized 204. FIX BIBLIOGRAPHY Vendamme, et al.
BIBLIOGRAPHY 1. Whitten, et al. 1035, General Chemistry. 7 th Ed Ibid. 3. Accessed on 17 May Accessed on 17 May Accessed on 18 May Accessed 18 May Accessed 19 May Accessed 13 June Accessed on 13 June Accessed on 16 June Accessed on 16 June Whitten Accessed on 13 June Accessed on 13 June 2007.
BIBLIOGRAPHY 15. “ Cancer Cell Imaging and Photothermal Therapy in the Near-Infrared Region by Using Gold Nanorods”. Huang, X.; El-Sayed, I. H.; Qian, W.; El-Sayed, M. A. J. Am. Chem. Soc.; (Article); 2006; 128(6); “Some Interesting Properties of Metals Confined in Time and Nanometer Space of Different Shapes”. Mostafa A. El-Sayed. Acc. Chem. Res. ; 2001; 34(4) pp “ Cancer Cell Imaging and Photothermal Therapy in the Near-Infrared Region by Using Gold Nanorods”. Huang, X.; El-Sayed, I. H.; Qian, W.; El-Sayed, M. A. J. Am. Chem. Soc.; (Article); 2006; 128(6); Ibid ?cookieSet=1#abstract Accessed 14 June Accessed 14 June Accessed 16 June Accessed 16 June Ibid.
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BIBLIOGRAPHY 41. Ibid. 42. Ibid Accessed 22 June Accessed 22 June Ibid 46. Ibid Accessed 22 June Accessed 23 June Accessed 23 June Ibid Accessed 23 June 2007.
BIBLIOGRAPHY 52. Ibid June Accessed 23 June Ibid June Ibid June June June Ibid. 62. Ibid.
BIBLIOGRAPHY 63. Accessed 24 June Ibid. 65. Ibid Accessed 24 June Ibid Accessed 24 June Ibid. 70. Ibid Accessed 24 June Ibid. 73. Ibid.
BIBLIOGRAPHY 74. Accessed 24 June Ibid. 76. Ibid June Accessed 24 June Accessed 24 June Accessed 24 June Ibid Accessed 24 June Ibid.
BIBLIOGRAPHY 84. Luis Hueso and Neil Mathur. “Nanotechnology: Dreams of a hollow future”. Nature. 427, (22 January 2004). 85. Ibid Accessed 25 June Accessed 25 June Accessed 25 June Ibid Accessed 25 June Accessed 25 June 2007.
BIBLIOGRAPHY Hydrogen_from_Coal_Projects.html Accessed 25 June Accessed 25 June Ibid. 95. doi: /j.biomaterials Accessed 25 June Ibid. 97. K. Fujihara, M. Kotaki and S. Ramakrishna. “Guided bone regenerationnext term membrane made of polycaprolactone/calcium carbonate composite nano- fibers”. Biomaterials. Volume 26, Issue 19, July 2005, Pages Accessed 25 June Ibid.
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BIBLIOGRAPHY 110. Ibid Ibid Accessed 28 June Binnig, et al. “Atomic Force Microscope” Physical Review of Letters. Vol 56. Issue 9. March 3, Meyer, Gehard and Amer, Nabil M. “Novel Optical Approach to Atomic Force Microscopy”. Applied Physics Letters. Vol 53. Issue 12. September 19, Ibid Ibid Accessed 28 June 2007.
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BIBLIOGRAPHY 128. Ibid Ibid Accessed 3 July Accessed 3 July Accessed 3 July Accessed 3 July Ibid Pierson, Hugh O., Handbook of Chemical Vapor Deposition: Principles, Technology and Applications. Noyes Publications: Park Ridge, New Jersey Pierson.
BIBLIOGRAPHY Accessed 3 July Celii & Butler. “Diamond Chemical Vapor Deposition”. Annual Review of Physical Chemistry. Vol Ibid Accessed 4 July Ibid Accessed 4 July Accessed 4 July Ibid Ibid Accessed 8 July 2007.
BIBLIOGRAPHY Cho, A. Y. and Arthur, J. R. “Molecular Beam Epitaxy”. Progress in Solid- State Chemistry. Vol 10. Part Accessed 8 July tesihtml/node24.html Accessed 8 July Ibid 151. Ibid ion-catalog.pdf Accessed 8 July regensburg.de/forschung/wegscheider/welcome_files/forschung_files/ epitaxie_files/whatismbe.html Accessed 8 July Accessed 29 July 2007.
BIBLIOGRAPHY Accessed 29 July J. Ristic, et al. “Characterization of GaN quantum discs embedded in Al x Ga 1-x N nanocolumns grown by molecular beam epitaxy”. Physical Review B. Vol 68. Issue 12. September Accessed 30 July Ibid Accessed 30 July Beam__-_UV/ Accessed 30 July Accessed 31 July 2007.
BIBLIOGRAPHY _E-Beam__-_UV/ Accessed 2 August Craighead, H.G., and Mankiewich, P.M. “Ultra-Small Metal Particle Arrays Produced by High Resolution Electron-Beam Lithography”. Journal of Applied Physics. Vol. 53. Issue 11. November Ibid Michael D. Fischbein and Marija Drndić. “Sub-10 nm Device Fabrication in a Transmission Electron Microscope”. Nano Letters. Vol. 7. Issue Accessed 7 July Chou, et al. “Imprint of Sub-25 nm Vias and Trenches in Polymers”. Applied Physics Letters. Vol 67. Issue November Charest, et al. “Combined Microscale Mechanical Topography and Chemical Patterns on Polymer Cell Culture Substrates”. Biomaterials. Vol. 27. Issue. 11 April Pg
BIBLIOGRAPHY Accessed 12 August ● Ibid. ● Accessed 21 August ● Accessed 21 August ● Accessed 21 August ● 241 Bohren and Clothiaux. Fundamentals of Atmospheric Radiation. Wiley-VHC, ● Accessed 21 August. ● Accessed 21 August Gupta, Rishi, and Stallcup II, Richard E. “Introduction to In Situ Nanomanipulation for Nanomaterials Engineering”. Scanning Microscopy for Nanotechnology. Ed by Zhou, Weilie, and Wang, Zhong Lin. Springer
BIBLIOGRAPHY Gupta Ibid Gupta forum/Forum_3/Talk/SeungHoonNahm.pdf Accessed 2 September 2007.http://www.andrew Ibid Ibid Accessed 4 September ● Ibid. ● 11 Caruso, Frank. “Nanoengineering of Particle Surfaces”. Advanced Materials. Vol 13. Issue 1. January 5, ● Accessed 7 September 2007.
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BIBLIOGRAPHY Sides Ibid Vendamme, et al. “Robust free-standing nanomembranes of organic/inorganic interpenetrating networks”. Nature Materials. Vol 5. Pages June 1, Sharp, Kenneth G. “Inorganic/Organic Hybrid Materials”. Advanced Materials. Vol 10. Issue 15. Pg January 26, Vendamme, et al Accessed 11 September Accessed 12 September 2007.