Drug delivery is an area that is already showing significant impact from nanotechnology, with some approaches using nanoparticles or nanocapsules to deliver drugs through the skin, lungs, stomach and eyes already in clinical trials and many more in preclinical trials.
The advantages of these approaches are varied, such as increased solubility, resistance to gastric enzymes (offering oral delivery of drugs previously needing intravenous delivery), controlled release or the ability to direct the drug, through various means, to where it is needed—almost all current medications are delivered to the body as a whole, which is fine as long as they only become active in the areas you want them to, but this is not usually the case. When the treatment is designed to kill cells, as in the case of cancer, the side effects are enormous.
Monday, August 4, 2008
NANO IN DRUG DELIVERY
Nanostructured Materials
Nanostructured materials, coupled with liquid crystals and chemical receptors offer the possibility of cheap, portable biodetectors that might, for instance, be worn as a badge. Such a badge could change color in the presence of a variety of chemicals and would have applications in hazardous environments.
Nanoparticles and nanowires
Another boon to bioanalysis looks set come from the attaching of nanoparticles to molecules of interest. Nanoparticles small enough to behave as quantum dots can be made to emit light at varying frequencies. If you can get particles that emit at different frequencies to attach to different molecules, you can spectroscopically determine the presence of many different molecules at the same time in a single sample. Several companies have been created to commercialize this and other variations on nanoparticle bioanalysis. One variation with similar applications, i.e. offering improved parallelism, uses instead nanowires that have distinctive stripes on them, like a bar code.
Others are exploiting the sensitivity of the electrical properties of nanowires (and even nanotubes) to develop highly sensitive biodetectors that could reveal the presence of a single molecule of substance. Quantum dots offer the same capability, for example by being stimulated to emit a photon in the presence of a certain molecule. Recent developments in single-photon detection and emission bear on this space too.
Nanopores and membranes
Nanomembranes also offer the ability to sort biomolecules and have already been shown capable of separating out left- and right-handed versions of molecules that come in mirror image forms. Usually only one of these is desired and the other may even be dangerous, as was the case with thalidomide.
Another intriguing application of tiny holes that is being worked on involves passing a single DNA or RNA thread through a nanosized pore, forcing it to straighten out and traverse the pore through a base at a time (a "base" being the fundamental coding element of nucleic acids). Changing electrical gradients on either side of the structure, containing the pore, or quantum tunneling current across the pore, could be used to identify the particular base that is passing through. The ability to sequence a whole genome (the sum total of genes in an organism) in a matter of hours has been proposed as a potential of this approach.
MEMS and micro fluidics
Micro technology is already making a major impact in the area of biological analysis and discovery. The basic science behind identifying the presence of a particular gene or protein has been developing for some time and is not considered nanotechnology per se, but MEMS and micro fluidics developments, such as the lab on a chip, are now offering a degree of parallelism that hasn't been seen before, the ability to detect much smaller quantities of a substance, equipment that can be taken out of the lab and carried around, increased automation by virtue of the integration of micro circuitry into the devices, and the benefits of the mass production approaches used in the semiconductor industry.
Tuesday, July 8, 2008
NANO IN SCIENCE
Nanoscience will have a huge impact on the biological sciences (and thus medicine and agriculture, for example) in the long term, and a significant impact in the short and medium terms, simply by virtue of our growing ability to work on the scale of biological systems. The impact will work both ways too—nature has evolved, over billions of years, mechanisms with a complexity, effectiveness and elegance that we will be hard-pressed to emulate, but which we most certainly can learn from. Nature is also the master of self-assembly. In fact nature makes things that self-assemble into things that self-assemble into other things that self-assemble. In the short term, nature will probably end up having more impact on nanotechnology than the other way around.
Another reason to expect great advances, whether nanotechnology-enabled or just assisted, is how little we still know about the natural world. We still can't explain, let alone cure, a large number of the diseases that afflict us, which means there's a great deal of scope here.
There is good reason to believe that in the not-too distant future we will indeed be able to cure a host of diseases and achieve much in the realm of biology and biotechnology, but it could be argued that most of that development will be attributable to long-established disciplines such as genetics and molecular biology, nanotechnology taking more of a supportive role. In the short and medium term, developments that appear achievable and that are clearly based on nanotechnology are not that dramatic, but do translate into large markets.
NANO IN LIFE SCIENCE
This is the area where nanotech has been most severely hyped, as a technology that will cure cancer, eliminate infections, enhance our intelligence and make us immortal. It is also the area where the bounds of nanotechnology are most blurred. This is because nature’s technology operates predominantly at the nanoscale. However our knowledge of the chemical structure of DNA and the proteins it codes for, and of the cellular machinery used to assemble the proteins, has for many years been classified under more traditional labels. But blurring of the boundaries is inevitable as we extend our senses and our ability to manipulate the world in this realm.
Display technologies
The hang-on-your-wall television (at an affordable price) has been awaited for a long time and nanotechnology may finally bring it into your home. Carbon nanotubes are excellent field emitters, i.e. they can be made to produce a stream of electrons, as does the electron gun in your bulky cathode ray tube TV. Several groups are promising consumer flat screens based on nanotubes by the end of 2003 or shortly after, but there are other competing technologies in the race. E-paper is another much heralded application and nanoparticles figure in several approaches being investigated, some of which promise limited commercialization in the next year or two. Soft lithography is another technology being applied in this area.
Optical Switching
Communications networks will no doubt continue to grow in capacity for some time as more people come to expect more from the Internet. Nanotechnology, or more specifically soft lithography (or nanoimprinting) is already being used in the production of sub-wavelength optical components. This is an area well worth keeping an eye on (the US optical switching market is expected to grow from $1.6 billion to $10.3 billion by 2004).
SPMs for Storage
Several variations on using scanning probe microscopes for data storage are being pursued, the three main varieties being based on using scanning tunneling microscopes on phase change materials (akin to the way Cd's work), magnetic force microscopes, and atomic force microscopes. This latter approach, which makes indentations in a polymer, has received the most publicity through IBM's Millipede project, which recently demonstrated recording densities of a terabit per square inch. The likeliest target for this particular technology is flash memory, used in mobile devices, because of low energy consumption and the potential of increasing memory to 5 - 10 gigabytes, where flash technology is unlikely to surpass 2 gigabytes.
Molecular and nanotube memories
Nanotubes hold promise for non-volatile memory and with a commercial prototype nanotube-based RAM predicted in 1 to 2 years, and terabyte capacity memories ultimately possible. Similar promises have been made of molecular memory from several companies, with one projecting a low-cost memory based on molecule-sized cylinders by end 2004 that will have capacities appropriate for the flash memory market. Note that all these approaches offer nonvolatile memory and if the predicted capacities of up to a terabyte can be achieved at appropriate cost then hard drives may no longer be necessary in PCs.
Monday, June 23, 2008
MAGNETIC RAM
There are several flavors of MRAM and one has seen limited commercial use already. MRAM offers a number of attractive features, including the fact that it is non-volatile, enabling devices such as a PC or mobile phone to boot up in little or no time. Several companies are working on MRAM technologies, and suggestions are that while the data densities might not be as good as with other technologies, cost per bit could be very low.
HARD DRIVES AND TAPES
Hard drives currently on the market for PCs have capacities in the tens of gigabytes and data densities of a few tens of gigabytes per square inch with 100 Gbits/sq. in. expected in the next generation. The use of magnetic nanoparticles offers the potential of terabyte drives, as does the patterned media approach being pursued by IBM and General Electric. Interestingly, this latter approach is being pursued using nanoimprinting technology. Fuji announced late in 2001 new magnetic coating promising 3-gigabyte floppy disks.
MEMORY AND STORAGE
We have noted that part of the difficulty in creating processors with nanotubes or molecular electronics relates to complexity. Data storage structures are far less complex than processors and many new technologies are converging on this area, promising commercialization in five years or less. Information storage requirements continue to grow but vary in nature from one application to another and can be approached in many ways. Magnetic disks in computers have been increasing their capacity in line with Moore's law, and have a market at the moment of over $40 billion. The other type of information storage common to all computers is DRAM (dynamic random access memory). DRAM provides very quick access but is comparatively expensive per bit. Magnetic disks can hold much more information but it takes much longer to access the data. Also, DRAM is volatile—the information disappears when the power is switched off. The trade-offs between access speeds, cost, storage density and volatility dictate the architecture of computers with respect to information storage. While hard disk technology continues to offer increasing data densities and lower costs per bit, a number of nanotechnologies are promising new types of RAM that are non-volatile and could have enough capacity to make disk storage unnecessary for applications such as personal computers. Companies are forecasting commercial products within two to four year time frames. How much penetration each technology will achieve in the variety of areas in which storage is used depends on the complex interplay of factors that have led to the current division of data storage technologies, but it would certainly be surprising if the consequences weren't disruptive for the industries
Sunday, June 8, 2008
Quantum Computing
In the much longer term quantum computing, offers staggering potential by virtue of the ability to perform simultaneous calculations on all the numbers that can be represented by an array of quantum bits (qubits). The scale at which quantum effects come into play, the atomic scale, argues for a requirement for nanoscale structures and quantum dots come up regularly in discussions of quantum computing. Primary applications would be in cryptography, simulation and modeling. The realization of a quantum computer is generally believed to be a long way off, despite some very active research. Funding in the area is thus still largely that provided for pure research, though some defense department money has been made available.
Spintronics
Magnetism is dictated by the direction of spin of electrons and increasing research into the use of this property has led to the coining of the term spintronics. The read heads of disk drives already exploit electron spin in an effect called giant magneto Resistance, as does MRAM (see later), which has already seen limited commercial production. An effect called ballistic magneto resistance has recently been demonstrated to have the capability of producing read heads that can deal with storage densities of a terabit per square inch—ten times the density expected in the next generation of hard drives. Commercial application of spintronics in electronics is farther away but the promise is there—a Canadian group recently created a transistor that was switched by the spin of a single electron confined in a quantum dot.
Molecular Nanoelectronics
Organic molecules have also been shown to have the necessary properties to be used in electronics and a single atom transistor was even demonstrated recently. Devices made of molecular components would be much smaller than those made by existing silicon technologies and ultimately offer the smallest electronics theoretically possible without moving into the realm of subatomic particles. The issues of connectivity, and thus mass production, apply to molecular electronics too, but choosing your molecule carefully does offer the potential of using self-assembly (discussed earlier) to create structures, an approach that could offer great economies.
Thursday, May 29, 2008
Carbon Nanotubes in Nanoelectronics
Carbon nanotubes hold promise as basic components for nanoelectronics—they can be conductors, semiconductors and insulators. In 2001 IBM made the most basic logic element, a NOT gate, out of a single nanotube, and researchers in Holland created a variety of more complex structures out of collections of tubes, including memory elements. Recently IBM created nanotube transistors that outperformed the best silicon devices available. There are two big hurdles to overcome for nanotube-based electronics. One is connectibility—it's one thing making a nanotube transistor, it's another to connect millions of them up together. The other is the ability to ramp up to mass production. Traditional lithographic techniques are based on very expensive masks that can then be used to print vast numbers of circuits, bringing the cost per transistor down to one five-hundredth of a US cent. Current approaches to nanotube electronics are typically one-component-at-a-time, which cannot prove economical. Molecular electronics (which, strictly speaking, includes nanotubes) faces similar scaling hurdles. There are some possible solutions, however.
NANO AFTER MORE'S LAW
You may have heard of Moore's law, which dictates that, the number of transistors in an integrated circuit doubles every 12 to 24 months. This has held true for about 40 years now, but the current lithographic technology has physical limits when it comes to making things smaller, and the semiconductor industry, which often refers to the collection of these as the "red brick wall", thinks that the wall will be hit in around fifteen years (the best resource for information on these limits is the International Technical Road map on Semiconductors - see http://public.itrs.net/). At that point a new technology will have to take over, and nanotechnology offers a variety of potentially viable options.
The total potential for nanotechnology in electronics has been estimated to be about $300 billion per year within 10 years, and another $300 billion per year for global integrated circuit sales (R. Doering, “Societal Implications of Scaling to Nanoelectronics,” 2001). But it's actually much harder to predict the commercially successful technologies in the world of electronics than in the world of materials.
The assumption that continually increasing processing power will automatically slot into a computer hardware market that continues to grow at the rate it has done historically, is not necessarily sound. Most of the growth over the last decade has been driven by personal computers and some argue that this market is nearing saturation. Certainly there will be other applications. Increasing the intelligence of computers, and giving them the capability to interact verbally in a sophisticated manner, would certainly bring benefits, but increasing hardware capabilities is only half the story, with the biggest challenges being designing the software. Another area predicted to see major growth, is ubiquitous computing, whereby processors start to be incorporated in all manner of objects around us, which then communicate with each other and us. However, the requirements here are for relatively simple processors and in many cases there is no need for them to be particularly small either. Cost improvements remain a critical factor and it is the correlation of increasing transistor density with a reduction in cost per transistor that has probably kept Moore's law on track for so long. This relationship need not continue, however and several new approaches, which aren't even nanoscale, hold promise of creating simple circuits cheaply, such as using arrays of MEMS-based micro mirrors to build custom circuits, or the use of ink jet printers to churn out simple ones (interestingly, nanoparticulates figure in the potential of this probably near-market technology). These approaches also offer the ability to create low runs of circuits, or even one-off bespoke designs, at low prices, whereas photo lithographic approaches need massive production runs to achieve economies of scale. Soft lithography, too, offers cheap, micro scale, circuitry and is being pursued in the creation of flexible displays. These technologies could take a share of the existing semiconductor market and certainly future markets such as electronic tagging of goods or the processors required for ubiquitous computing.
High-production-run electronics will continue to be dominated by photo lithographic approaches for years to come, with the advent of the molecular nanotechnologies that could dramatically improve the power and density of processors while competing with photo lithography on cost still way off the radar for the investment community. The reason for this is the challenge of using such approaches to create the complex structures required for processors, an obstacle that doesn't apply to data storage, as we will see later. Soft lithography and nanoimprinting, however, are showing promise of coming into investment range in the near future. A company has already been formed to develop one flavor of soft lithography, the step and flash approach, for nanoelectronics and Stephen Chou of Princeton recently developed a variant of his nanoimprinting approach (already used to make commercially available sub wavelength optical components) to make nanoscale structures by melting silicon.
ELECTRONICS AND INFORMATION TECHNOLOGY
The impact of the information technology (IT) revolution on our world has far from run its course and will surely outstrip the impact of the industrial revolution. Some might claim it has done so already. Key to this is decades of increasing computer power in a smaller space at a lower cost.
Saturday, May 17, 2008
DEVICES
MEMS. Making machines in the micro realm is something that is already well established. Microelectromechanical systems (MEMS) are generally constructed using the same photolithographic techniques as silicon chips and have been made with elements that perform the functions of most fundamental macro scale device elements - levers, sensors, pumps, rotors, etc. MEMS already represent a $4 billion industry, which is projected to grow to $11 billion by 2005.
NEMS. Moving to the nanoscale will present a host of new issues. For this reason, and possibly a lack of economic drivers for making machines smaller in general (smaller isn’t necessarily better), we shouldn't expect a vast array of products to flow out of MEMS and the nano version, NEMS, in the near future. However, there is sure to be a significant but modest evolution, especially in such areas as lab-on-a-chip type technologies, and NEMS devices have potential in the telecoms industry.
Tiny Medical Devices. MEMS and NEMS hold promise in the medical field, as little devices controlling the release of a drug, for instance, or even in the control functions of prosthetics, such as artificial hearts. However, it should be noted that where a passive system can perform the same function as an active one, the passive one would normally be less expensive and more reliable. Sometimes, however, an active device makes sense—recently a MEMS device was created that can grip and release individual blood cells without harming them. One can imagine such a device being used in a system to inject genes or other substances into cells. The use of nanotubes as syringes has even been suggested.
Advanced Lasers. Lasers constitute an area that is likely to be commercially affected by nanotechnology in the near future. Quantum dots and nanoporous silicon both offer the potential of producing tunable lasers—ones where we can choose the wavelength of the emitted light. Classic lasers, including solid-state ones, are dependent upon the physical and chemical properties of their components and are thus not tunable. Given the market for solid-state lasers, developments in this area are likely to be commercially significant.
Tuesday, May 13, 2008
DIP-PEN NANOLITHOGRAPHY
This technique uses atomic force microscope (AFM) tips like old-fashioned quill pens, depositing an ink on a surface, the ink usually being something that forms self-assembled monolayers. A variation uses hollow AFM tips that have a well to hold the ink.
Lines just a few nanometers across have been created and, in theory, a wide variety of different inks can be used. The approach clearly offers great flexibility but not the sort of throughput that would be required for mass production. Throughput can be increased significantly by having arrays of tips, and companies working on the technology talk of potentially hundreds of thousands.
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Thursday, May 8, 2008
SOFT LITHOGRAPHY
Soft Lithography
This term covers a variety of approaches akin to traditional printing. A mold is created that can then is used to make an imprint in a material or apply ink to it, plus there are several other variations. A variant already used in creating optical components is nanoimprinting, which uses a hard mold to make an impression in a polymer. A recent variation on this uses a quartz mold, which is placed in contact with silicon. The silicon is then melted with a powerful laser, leaving an impression of the mold.
In general, no special technology is required for these techniques, nor are the fantastically clean environments required for existing silicon chip production, for example. Additionally, a wide variety of materials can be used.
Soft lithography is already used to make micro fluidic systems, such as those in labon- a-chip systems, and it scales readily down to the nanoscale—depending on the variant of the technology used, resolution can get below 10 nanometers. The attraction for nanoelectronics is clear—the technology is simple, offers a high level of parallelism (and thus economies of scale from high production runs), and can produce complex patterns with nanoscale features. As a replacement for traditional lithography for creating electronic devices, however, there is currently a major obstacle—the technique is not well suited to making the precisely aligned, multilayered structures currently used in microelectronics, although work is being done to overcome this limitation.
The alignment problem is lessened if larger feature sizes are acceptable and the approach has been investigated for making flexible displays. Additionally, the creation of the master is much cheaper than for photolithography and the process would become economical for much lower production runs, such as for device specific electronics.
TECHNIQUES FOR BUILDING NANO SCALE STRUCTURES
Self-assembly. Self-assembly is nature's favorite way of building things. Simply create materials that naturally combine with each other in desired ways. Self-assembled monolayers, which we have already mentioned, are a simple example.
Self-assembly typifies an approach that is often mentioned in writings on nanotechnology, the bottom-up approach. Assembling a car engine, say, from its components is a bottom-up approach (although not an example of self-assembly) and involves little wastage. Machining some of the components out of blocks of material is a top-down approach, and involves more wastage.
Self-assembly potentially offers huge economies, and is considered to have great potential in nanoelectronics for this reason and because it could produce just about the densest electronics feasible. It is a part of some of the promising approaches to making molecular memory that may bear fruit in a few years. Tackling processors is another matter, however, because of the greater complexity involved? In this area self-assembly will likely be combined initially with some more traditional top-down approach, for example, getting molecular components to self-assemble on a patterned substrate in some sort of hybrid system, which many believe will represent the first commercialization of nanoelectronics.
A drawback of self-assembly approaches to date is that they are not that reliable and the results have a much higher rate of variability (read flaws) way to get around this is to design software that takes account of the flaws and allows imperfect circuitry to operate reliably, through testing and selection of viable components. than we are accustomed to with lithographic approaches.
Saturday, May 3, 2008
NANO SILVER BULLET
The new science of nanotechnology allows manufacturers to use materials that measure between 1 and 100 nanometers. (A nanometer is a billionth of a meter, or roughly 1/100,000 the width of a human hair.) While nanoparticles can occur naturally and by accident--in diesel soot, for example--it's only in the past decade or so that scientists have widely learned to create and manipulate them. Many nanotechnologies use nano-versions of common materials, like carbon and silver. These tiny particles take on almost magical qualities: Insoluble materials can become soluble, nonconductive substances start conducting electricity. Nanomaterials can be orders of magnitude more powerful than the same substance at normal scale. Myriad green applications are in the works, and medical miracles are promised.
For now, though, nanotech is largely used in industrial and consumer products, from cosmetics to fleece to plastic food containers. Often, the benefits are more convenient than essential: White sunscreen turns clear on the skin; fabrics resist stains and static; leftovers stay fresh longer. There are over 600 nano consumer products on the market today--up from about 200 two years ago, when the Washington-based Project on Emerging Nanotechnologies (PEN) started keeping an inventory--with three to four new products added weekly.
ROLE OF NANO IN NATURE
A role for nanotechnology in capturing and storing green house gases The greenhouse effect is primarily a function of the concentration of water vapor, carbon dioxide, and other trace gases in the Earth's atmosphere that absorb the terrestrial radiation leaving the surface of the Earth. Changes in the atmospheric concentrations of these greenhouse gases can alter the balance of energy transfers between the atmosphere, space, land, and the oceans. The capture and storage of greenhouse gases could play a significant role in reducing the release of greenhouse gases into the atmosphere (read more about capture and storage of carbon dioxide here). Carbon dioxide (CO2) is the most important greenhouse gas and captures the limelight in most reports on global warming. While other greenhouse gases make up less of the atmosphere, they account for about 40 percent of the greenhouse gas radiation sent back to Earth. They can also be much more efficient at absorbing and re-emitting radiation than carbon dioxide, so they are small but important elements in the equation. In fact, molecule-for-molecule some gases containing lots of fluorine are 10,000 times stronger at absorbing radiation than carbon dioxide. A new systematic computational study shows an interesting approach of how nanotechnology, in this case the use of carbon nanotubes and other nanomaterials, could lead to effective filters for the capture and storage of greenhouse gases. ...more
Thursday, April 24, 2008
VIRTUAL KEY BOARD
Your computer keyboard is probably a magnet for spilled soda, crumbs, dust, and other unsavory debris. Dump enough junk between the keys and the circuit board below--a "mini-computer" equipped with hundreds of pulsing electric circuit switches--will eventually bonk..
WANNA GET RID OF THEMNow such messes may soon be history, thanks to inventors at the Israeli company VKB. Their stroke of genius: a neon red full-size virtual keyboard projects onto any flat surface. The device consists of a mini-projector that fires infrared laser beams (fast-moving energy waves) in the shape of a real keyboard, and a sensor that detects when the beams are broken by hand movement
Now, however, we get a little glimpse with promise that we're not that far off of schedule. You can now get the Laser Virtual Keyboard for quite a reasonable price. Powered by Blue tooth, the matchbox-sized device uses a laser to project a 63 key QWERTY keyboard onto any flat surface. Designed to work with Palm, Symbian and Windows Mobile operating systems, it was originally meant for your PDA. Fortunately, it is supported by Windowsxp, and has some OS X support as well. This is a great idea, even if it is plagued by two gaping holes: two hours of battery life and a 63 key keyboard. According to Think Geek, it comes with an AC adapter, so for desktop use it'll do fine (if you actually have a spare power outlet). I think the biggest hurdle is the tiny keyboard. Sure, 63 keys is fine for your PDA, but for your PC, 102 is the only way to go. After all, those function keys are pretty handy.
Despite these limitations, this is a brilliant idea. This virtual keyboard has the amazing ability to be immune from spills, crumbs, dirt and cat hair (I know that one way too well.). And of course, the high-tech wow factor. This thing just looks cool, and would impress just about anyone. When the 102 key models come out, I think my current keyboard will have to be retired.
This is a projector concept by designer Sunman Kwon uses similar technology to that of the Virtual Keyboard . Each of your finger segments on the inside of your hand are turned into keys, representing three letters for each segment or joint. What you end up with, is a keyboard literally in the palm of your hand. This would make for a remarkably portable input device that could just dangle on your wrist waiting for the next time you needed it, then with a little Bluetooth handshake, you're ready to type up a storm.
More and more people are relying on portable media devices for everyday instead of desktop pc's, meaning that they have to rely on the tiny keyboards that are part of the interface of their PDA or cellphone . A standard computer keyboard would not be a practical accessory, no matter how much faster correspondence would become, but the Projector Keyboard can solve that problem. The keyboard is about the size of a small cell phone itself and projects a standard keyboard onto any flat surface, from the table.
Saturday, April 19, 2008
SOME OTHER APPLICATIONS
Optical Techniques. Optical techniques are in theory limited in resolution to half the wavelength of the light being used, which keeps them out of the lower nanoscale, but various approaches can overcome these limits, such as the use of quantum mechanical properties of light or interferometry (measuring things using the interference of light beams), which has recently been shown to have the potential to detect movements at a 1000th of the wavelength of the light being used.
Litho graphics. The mask-based lithographic tools and techniques used in the traditional semiconductor industry have also entered the nano realm (sub 100nm), but not yet for mass production.
Additional Tools. The list is by no means complete. A few other tools and techniques that operate on the nanoscale are: nuclear magnetic resonance; molecular beam epitaxy and laser tweezers (whereby laser beams are used to hold and manipulate molecules). ; And a tool called the nanomanipulator that borrows from the world of virtual reality to allow researchers to "feel" individual atoms. Research into new tools and techniques is extremely vibrant.
Computer Modeling. Finally, a mention of a tool that goes back some years now but will surely have an impact on nanotechnology, computer modeling (much used by the molecular nanotechnologists). New supercomputers are being commissioned, and distributed computing is being brought into play to simulate the behavior of matter at the atomic and molecular level. The study of the way proteins fold (an essential determinant of their function), and efforts to predict this, represent one well established application, and modeling of billions of atoms to predict the behavior of bulk solids is now being achieved. Computer modeling will no doubt prove very useful in understanding and predicting the behavior of nanoscale structures because they operate at what is sometimes referred to as the mesoscale, an area where both classical and quantum mechanics influence behavior. While researchers are used to using the mathematics behind classical and quantum mechanics individually, the combination of the two in the same structures presents challenges and new models that incorporate both, and their interplay, are becoming increasingly important.
Sunday, April 13, 2008
IN TOOLS
Before you can make something, you have to have the tools. For this reason, this category has the greatest number of established companies. By tools we mean the collection of technologies that allow us to see, manipulate and engineer at the atomic level.
STMs. It is now twenty years since the scanning tunneling microscope (STM) was invented, allowing us to see atoms for the first time. The STM works by detecting small currents flowing between the microscope tip and the sample being observed (the current flows because of quantum mechanical tunneling).
AFMs. Five years later a device with similar capabilities, the atomic force microscope (AFM), was invented, which has a tiny probe on the end of a cantilever (like a springboard). The probe makes contact with the surface of the sample and, as it moves over it, is deflected by the variations in the surface, causing the cantilever to bend. A laser beam detects the bending of the cantilever and, again, we get atomic resolution. Advances are being made in using these in various mediums, including liquids, which is particularly useful for looking at biological samples.
Scanning Probe Microscopes. The AFM and the STM are collectively called scanning probe microscopes and can not just produce images but actually move atoms around, as was demonstrated when IBM used an SPM to write the company's letters in xenon atoms (see picture). SPMs have potential for high-density data storage technologies and can be used to write nanoscale lines, as in dip-pen nanolithography. In case you are imagining some vast machine in a laboratory, AFMs and STMs can be bought as devices not much bigger than a mouse that plug into a computer's USB port.
APPLICATIONS
Probably the two most useful ways of organizing the nanotech world are through the technology, i.e. what is being made, and through applications, i.e. where these products will find a home. For our concise introduction, we use a mixture:
- Tools
- Materials
- Devices
- Techniques for Building Nanoscale Structures
- Electronics and Information Technology
- Life Sciences
- Power and Processes and the Environment
Any attempt to categorize the world in such a crude way is necessarily imperfect and there will always be certain technologies that span groups or do not fit neatly into one or the other. Furthermore, the multidisciplinary nature of nanotechnology means that is difficult to separate advances in, for example, tools, from their effect on life sciences.
ABILITY TO SHRINK STUFF
Another common misconception is that nanotechnology is primarily concerned with making things smaller. This has been exacerbated by images of tiny bulls, and miniature guitars that can be strummed with the tip of an AFM, that while newsworthy; merely demonstrate our newfound control of matter at the sub-micron scale. While almost the whole focus of micro-technologies has been on taking macro-scale devices such as transistors and mechanical systems and making them smaller, nanotechnology is more concerned with our ability to create from the bottom up. In electronics, there is a growing realization that with the end of the CMOS roadmap in sight at around 10 nm, combined with the uncertainly principal's limit of Von Neuman electronics at 2 nm, that merely making things smaller will not help us. Replacing CMOS transistors on a one for one basis with some type of nano device would have the effect of drastically increasing fabrication costs, while offering only a marginal improvement over current technologies.
However, nanotechnology offers us a way out of this technological and financial cul-de-sac by building devices from the bottom up. Techniques such as self assembly, perhaps assisted by templates created by nano imprint lithography, a notable European success, combined with our understanding of the workings of polymers and molecules such as Rotoxane at the nanoscale open up a whole new host of possibilities. Whether it is avoiding Moore's second law by switching to plastic electronics or using molecular electronics, our understanding of the behavior of materials on the scale of small molecules allows a variety of alternative approaches, to produce smarter, cheaper devices. The new understandings will also allow us to design new architectures; with the end result that functionality will become a more valid measure of performance than transistor density or operations per second.
NANOTECHNOLOGY A FANTASTIC VOYAGE
Shrinking machines down to the size where they can be inserted into the human body in order to detect and repair diseased cells is a popular idea of the benefits of nanotechnology, and one that even comes close to reality. Many companies are already in clinical trials for drug delivery mechanisms based on nanotechnology, but unfortunately none of them involve miniature submarines. It turns out that there are whole ranges of more efficient ways that nanotechnology can enable better drug delivery without resorting to the use of nanomachines.
Just the concept of navigating ones way around the body at will does not bear serious scrutiny. Imagine attempting to go against the flow in an artery-- it would be like swimming upstream in a fast flowing river, while boulders the size of houses, red and while blood cells, rained down on you. Current medical applications of nanotechnology are far more likely to involve improved delivery methods, such as pulmonary or epidermal methods to avoid having to pass through the stomach, encapsulation for both delivery and delayed release, and eventually the integration of detection with delivery, in order for drugs to be delivered exactly where they are needed, thus minimizing side effects on healthy tissue and cells. As far as navigation goes, delivery will be by exactly the same method that the human body uses, going with the flow and `dropping anchor' when the drug encounters its target.
NANOTECHNOLOGY AS SCIENCE FRICTION
While there is a commonly held belief that nanotechnology is a futuristic science with applications 25 years in the future and beyond, nanotechnology is anything but science fiction. In the last 15 years over a dozen Nobel prizes have been awarded in nanotechnology, from the development of the scanning probe microscope (SPM), to the discovery of fullerenes. According to CMP CientÃfica, over 600 companies are currently active in nanotechnology, from small venture capital backed start-ups to some of the world's largest corporations such as IBM and Samsung. Governments and corporations worldwide have ploughed over $4 billion into nanotechnology in the last year alone. Almost every university in the world has a nanotechnology department, or will have at least applied for the funding for one.
Even more significantly, there are companies applying nanotechnology to a variety of products we can already buy, such as automobile parts, clothing and ski wax. Nanotechnology is already all around us if you know where to look.
The confusion arises in part because many people in the business world do not know where to look. Over the last decade, technology has become synonymous with computers, software and communications, whether the Internet or mobile telephones. Many of the initial applications of nanotechnology are materials related, such as additives for plastics, nanocarbon particles for improved steels, coatings and improved catalysts for the petrochemical industry. All of these are technology-based industries, maybe not new ones, but industries with multi-billion dollar markets.
MOLECULAR MACHINES
Then comes the second big idea, getting these molecular machines to make copies of themselves, which then make copies of themselves, which then make copies, and so on. This would lead to exponential growth of tiny machines that could then be used to construct macro scale objects from appropriate molecular feedstock’s, and with no wastage. In theory, large, complex structures could be built with atomic precision out of something as robust as diamond, or similar "diamondoid" substances. This is molecular manufacturing.
These ideas were first made widely known by Dr. K. Eric Drexler in his 1986 book Engines of Creation, and have since then found their home at the Foresight Institute (www.foresight.org) and the Institute for Molecular Manufacturing (www.imm.org). Drexler followed up in 1992 with a more technical look at the subject in his book Nanosystems, and is currently working on an updated edition of "Engines".
The potential of such technology to change our world is indeed truly staggering, if it can be realized. Whether it can or not is a subject of debate, sometimes fierce. There is, though, an unassailable argument for the feasibility, in principle, of self-replicating machines that construct things on a molecular level, this being that they already exist—all living things, including ourselves, are built this way. However, Drexler also went on to outline scenarios for making and organizing armies of programmable assemblers. These scenarios are quite different from what we see in nature and here there is certainly more room for debate, especially about matters of complexity, control, and the practicability of making assemblers general purpose (molecular machinery in nature is generally very specific in function, but operates in concert with a host of other machines in a hugely-complex orchestrated effort that is still poorly understood). It has been argued that approaches more akin to those used by nature might be more fruitful than some outlined by Drexler. On the other hand, nature's technology has evolved by chance. Conscious design could in principle allow the creation of machines and materials that nature never produced.
If you accept that general-purpose, programmable assemblers can be constructed, you still have to be careful about predicting what they could make. Building up a three-dimensional structure purely out of diamond, even one with a complex shape, is a relatively simple programming task. Making a steak, which is in turn made of cells, which are themselves vastly complex machines, is another matter altogether. Drexler never made such a suggestion, but it and similar have appeared in the media, which has done nothing to promote public understanding or reasoned debate.
Drexler speculated extensively on the possibilities of molecular machines and saw the potential for not only a dramatic impacts on society the world over, but also dangers. The most famous, and contentious, of these is the prospect of self-replicating assemblers getting out of control and consuming everything in their path to make more copies of themselves, turning everything into”gray goo" in the process. There are good arguments against such an apocalyptic scenario, some of which are presented on the Foresight Institute's own web site (http://www.foresight.org/NanoRev/Ecophagy.html), but a replicating machine could certainly present dangers comparable to a genetically engineered virus, and probably worse (genetically engineered viruses, however, will remain a much more real threat for some time to come). Drexler's recognition of the potential impact and dangers led him to decide that, even if they were still a long way off, it wasn't too early to start preparing for them. A part of the mission of the Foresight Institute, and the research oriented Institute for Molecular Manufacturing, is to do just that. Their guidelines for developing molecular nanotechnology responsibly are outlined at http://www.foresight.org/guidelines/current.html.
Assuming that a molecular assembler, as envisaged by Drexler, can be made (and be made to be economically productive), it won't be for some time yet—even the optimists talk about a period of ten to twenty years or more. However, current work on molecular nanotechnology is not limited to theoretical papers and computer models. The company Zyvex, which bills itself as the world's first molecular nanotechnology company, has recently teamed up with some respected academic groups and attracted government funding to work on building assemblers, starting at the micro scale but, hopefully, moving down to the nanoscale.
LONG TERM POSSIBILITIES
You may have read in the popular press of an imminent future, with tiny submarines patrolling our bodies, stitching up damaged tissue, zapping an occasional cancer cell or invading virus or switching off an errant gene; nanorobots weaving extensions to our brains to enhance our intelligence; desktop machines that can make you a diamond ring; a table that will transform into a chair at the flick of a remote control; and even immortality. These examples represent the sensationalism and distortion of the popular press but are based on some seriously made predictions of possible futures. Still, it's just so much science fiction, surely?
Not necessarily. While some of the wilder visions of nanotech-enabled futures are extremely speculative, they stem largely from quite straightforward ideas founded in solid science, and generally referred to as molecular nanotechnology (MNT). However, it is important to distinguish between MNT, the potential benefits of which are long term, and the mainstream applications of nanotechnology, which are of more interest to investors in the near and medium terms. There is big difference between molecular assemblers and the use of nanoclay particles as additives in the plastics industry. Failure to distinguish between what is available now and what is theoretically possible at some point in the future has been the cause of many of the misconceptions about nanotechnology. It should be noted that MNT has attracted little interest from the business community, owing to its long timescales, and has not, rightly or wrongly, been accepted by the scientific community at large.
The core idea of MNT is that of making robotic machines, called assemblers, on a molecular scale, that are capable of constructing materials an atom or a molecule at a time by precisely placing reactive groups (this is called positional assembly). This could lead to the creation of new substances not found in nature and which cannot be synthesized by existing methods such as solution chemistry. Molecular modeling has been used to support the potential existence and stability of such materials.
Tuesday, April 8, 2008
SOURCES IN VARIOUS OTHER COUNTRIES
- EC
European Consortium on Nanomaterials
Network on Nanoelectronics "Phantoms", lead by the Inter-university
Microelectronics Center (IMEC), Liuven, Belgium
- Germany
Network of competency in nanotechnology, 6 centers territorially distributed
Institute of Nanotechnology, Karlsruhe
- France
Institute for Micro and Nanotechnologies (MINATECH), Grenoble, France (Established in 2001)
- Sweden
The Nanometer Structure Consortium, Lund
- Switzerland
Nanotechnology Network, coordinated from University of Basel, Switzerland
- Canada
National Institute of nanotechnology (established in 2001)
- Brazil
National Synchrotron Light Laboratory
- China
National Nanotechnology Research Center, Beijing (established in 2001)
- Taiwan
Industrial Technology Research Institute (established in 2001)
- Korea
Nanodevice R&D network
- Russia
Institute of Applied Physics, St. Petersburg
- Australia
CSIRO Nanotechnology Group (established in 2001)
- Romania
Nanotechnology Center, National Institute of Microsystems
Nanostructured Materials Center, National Institute of Physics
- Israel
Group of four academic centers at the Tel Aviv University, Technion University, Hebrew University, and Ben Gurion University (established in 2001)
GOVERMENT SOURCES,CENTERS IN JAPAN
Nanotechnology Research Center, RIKEN (Center established in 2001)
Institute of Nanomaterials, Tohoku University, Sendai
Nanomaterials Laboratory, National Institute of Materials Science, Tsukuba (established in 2001)
Silicon Nanotechnology Center, Tsukuba (established in 2001)
Sunday, April 6, 2008
Examples of centers and networks primarily supported by government sources
While single and smaller group investigators do most of the nanoscale R&D, the larger research centers play an essential role in the development of major topics and establishing of partnerships. Centers providelong-term coherence, interdisciplinary, and a meeting place of people with multiple expertise and tools covering the various needs of nanotechnology development. A large proportion of the major nanotechnology centers around the world have been established in the last year. Several illustrations of key research centers are listed below:
- In the U.S.
National Nanofabrication User Network (NNUN):
5 universities, with the lead at the Cornell University
Distributed Center for Advanced Electronics Simulation (DesCArtES):
4 universities with the lead at the University of Illinois - Urbana
Materials Research Science and Technology Centers: distributed through U.S.
Engineering Research Centers, components on nanotechnology
Nanobiotechnology Science and Technology Center (Cornell University)
Nanoscale Science and Engineering Centers (6 centers established in 2001)
California NanoSystems Institute (established in 2001)
NASA Nanoscience Centers (3 university based centers established in 2001)
DOE Nanoscience Laboratories (3 national laboratory centers to be established in 2002)
NANOTECH ORGANISATIONS
Some non-profit nanotech organizations
European NanoBusiness Association
Institute of Nanotechnology (UK)
The NanoBusiness Alliance (US)
Canadian Nanobusiness Alliance
NanoSIG
Beckman Institute (US)
Center for Nanospace Technologies (US)
Foresight Institute (US)
Institute for Molecular Manufacturing (US)
Michigan Molecular Institute (US)
The interest from the investment community has been sparked by some impressive-sounding claims about the potential revenues that nanotechnology will generate, although VCs are showing a healthy level of caution when it comes to actually handing over money. The US's National Science Foundation predicts that the total market for nanotech products and services will reach $1 trillion by 2015 (National Science Foundation, “Societal Implications of Nanoscience and Nanotechnology,” March 2001) and huge variations in existing and predicted market sizes have been seen. These are generally offered unqualified and the size of some figures suggests that they are including revenues for any industry seeing an impact from nanotech. Counting the revenues of these industries as nanotechnology revenues is misleading. The huge semiconductor industry is moving into the nanoscale and companies in the sector are sometimes casting themselves as nanotechnology companies. Considering the revenues of the semiconductor industry, as nanotechnology will produce figures that are of use to no one—a more sophisticated approach is needed, separating out pure nanotechnology revenues, such as those of nanotube manufacturers, from the contribution of nanotechnology to existing industries.
A number of non-profit organizations focused on the development of nanotechnology have been in existence for some time, while still others are just now being created. Europe now has 86 nanotechnology networks, although most of these are purely scientific in nature.
We would categorize most of the activities discussed so far as relating to short- or medium-term technologies. In the long-term category there are ideas that often sound like science fiction and which are often over-hyped and misunderstood by the press or dismissed out of hand as fantasy. With the rider that these ideas are not just long-term, but often speculative, now we'll take a brief look at them.
