Subjects to link:

• The blue lemon 25 April 2002 from Nature News

• Fungus with the Midas touch 16 May 2002 from Nature News

• Lander leaves its mark 18 April 2002 from Nature News

• Carbon Nanotube Lighting Reported by: Bonard, et al., Applied Physics Letters, 30 April, 2001.

• IBM研發下一代晶片技術獲突破 奈米技術建奇功, 27 April, 2001.

• Surface Plasmon Molecules Reported by: L. Martín-Moreno, F. J. García-Vidal, H. J. Lezec, K. M. Pellerin, T. Thio, J. B. Pendry, and T. W. Ebbesen, in Physical Review Letters 86, 1114 (5 February 2001).

• Scientists Find That Electrical Resistance Between Nanotubes, Graphite Is Tunable 

• On the Spintronics

• OLED 2000 from Nature News

• Solar power goes organic from Nature News

• Physicists squeeze laser light from silicon from Nature News

• On the Carbon Nanotubes from Nature News

• Quantum Heat from Nature News

• The molecular torch from Nature News

• Little lasers from Nature News

• A Clinton Initiative in a Science of Smallness from New York Times

• Clinton seeking multi-billion-dollar boost in science, research funds from CNN

• Clinton to request funding increase for 'bioenergy' product research from CNN

• Computer Scientists Are Poised For Revolution on a Tiny Scale from New York Times

• Japanese invent world's tiniest robot from CNN

• WHAT'S NEXT; A Stay of Execution For the Silicon Chip from New York Times

• A taste of the future: the electronic tongue from CNN

• World's smallest 'pen' draws tiny circuits from CNN

• Researchers make a 'machine' out of DNA from CNN

• Technology spells MEMS in future from USA Today

• All the answers, one tiny package from USA Today

Achim Müller and colleagues at the University of Bielefeld have created a kind of lemon-shaped hollow cage in which the shell is composed mostly of octahedral building blocks¹. These octahedra contain molybdenum in the +V and +VI oxidation states coordinated to oxygen, water and some sulphate ligands. The cage — essentially a sphere open at two tapering necks — has an internal cavity measuring about 2.5 by 4 nm, which contains about 400 water molecules in the crystalline material.

This is by no means the first demonstration that complex yet orderly nanostructures can be made from inorganic units. Müller's group has pioneered the use of molybdenum oxide polyhedra as nanoscale building blocks, previously reporting their assembly into mesoscale wheel and ball clusters².

Copyright GettyImages

Whereas other microorganisms, including some fungi, are known to synthesize metal nanoparticles inside the cell, M. Islam Khan and colleagues at the National Chemical Laboratory in Pune have discovered that the fungus Fusarium oxysporum creates such particles extracellularly¹. This means that the cells don't have to be split open in order to claim the gold bounty, so the fungus could be continuously cultivated in vitro as a nanoparticle factory.

Tiny columns of carbon, only nanometers in diameter, emit the electrons that make this bulb glow. New techniques for growing the nanotubes on unusual surfaces, such as the cathode wire running down the center of the bulb, may lead to improved vacuum gauges and magnetic field sensors, among other devices.

New research provides a detailed explanation for a baffling effect in which much larger-than-expected amounts of light passed through a silver-coated quartz barrier with tiny openings: namely, a periodic array of 150-nm holes up to 10 times smaller than the wavelength of the light sent through. This unexpected experimental effect bodes well for scaling down optical devices to nanometer dimensions.

Light can pass through such tiny holes due to the actions of surface plasmons (SPs), collective oscillations of electrons at the boundary between conductors and insulators. According to one of the research collaborations investigating this effect, the light gets through the holes in the form of an SP "molecule," consisting of two polaritons, one on each side of the metal film, that interact with one another with exponentially decaying electromagnetic fields, forming "molecular" levels in very much the same way that atomic electron wavefunctions interact to form molecular levels in a diatomic molecule.

The plot illustrates the effect of the SP molecules. The x axis depicts the propagation of light. The y-axis runs along a cut of the periodic array of holes (the cut considered is represented schematically in the upper left panel).

To show more clearly the formation of the SP molecule, this plot neglects the effects of light absorption by the metal. The upper right panel shows the wavelengths (780 and 788 nm) at which light is transmitted through the metal in this case.

As researchers discovered, the mathematics of the SP molecule's electromagnetic field are essentially the same as the ones describing the formation of molecular electronic levels from the levels of (otherwise) isolated atoms. Suppose there are two atoms that, when very far apart, have their own sets of energy levels. When the atoms come closer, these separate sets of energy levels combine to form a set of molecular levels.

In the plasmon molecule something analogous occurs: if the two metal surfaces were very far apart, there would be two isolated surface plasmons . If the metal is not too thick, these two surface plasmons "talk" to each other, and form a set of combined levels.

Two separate cases are shown in (a) and (b), corresponding to the two different plasmon molecule levels: the symmetric (b) and antisymmetric (a) linear combination of surface plasmons at both interfaces. Note that, as expected, in the antisymmetric case the electric field intensity at the middle of the hole is much smaller than in the symmetric case.

It is also worth noticing the huge enhancement of the fields at the surfaces, by a factor of order 500 in intensity, due to the plasmons. In this scale the field of the incoming and outgoing wave cannot be resolved, so large are the fields close to the metal!

(Thanks to Luis Martin Moreno and Francisco Jose Garcia Vidal for providing the figure and the explanation.)

The National Science Foundation, the National Institutes of Health and the Office of Naval Research supported the continuing experiments.

The lifeblood of electronics is the movement of charged objects, usually electrons or holes (places where an electron ought to be but isn't). But besides having mass and charge, electrons possess a magnetic moment, or spin; that is, they behave like little magnets. The use of these spins, independent of charge, might prove to be a valuable commodity for processing information, not least in the area of quantum computing. Indeed, various "spintronic" devices (such as a spin transistor) have already been demonstrated. Can one have a current of spins without also an underlying current of charge? Two physicists at the University of Toronto (Ravi Bhat, 416-978-4364, rbhat@physics.utoronto.ca) propose to do exactly that by illuminating an ensemble of electrons in a semiconductor with light from a pair of laser beams. The light would not only polarize the electrons (orient their spins in space, something which has been done before; see Update 472) but move the electrons around without the need of any applied voltage by manipulating the pattern of interference between the two laser beams. (Bhat and Sipe, Physical Review Letters, 18 December 2000.)

A jellyfish is the inspiration for a new range of light-emitting diodes (LEDs). A group of US electrical engineers report in Advanced Materials[1] that they have used a fluorescent protein found in jellyfish to synthesize materials that emit light when electricity flows through them. These LEDs may ultimately lead to better full-colour flat-screen displays for portable computers.

A substance called green fluorescent protein, or GFP, makes the Pacific Ocean jellyfish Aequorea victoria glow green. GFP collects the energy produced in a cellular chemical reaction and emits it as green light from a small molecular unit called a 'chromophore' in its long molecular chain.

GFP has long been used as a marker by biologists. Now scientists making light-emitting devices have become attracted to the efficiency and the highly specific colour of the chromophore's emission process.

Mark Thompson of the University of Southern California in Los Angeles and co-workers have created a variety of fluorescent molecules that mimic the chromophore -- but without the surrounding protein scaffolding which would stymie an electrically controlled device.

The researchers are optimistic about the prospects for this approach. "There are an enormous variety of fluorescent organisms," they say. "Other materials can be prepared, using the insight provided by [these] naturally occurring systems, which may be useful in electronic and optoelectronic applications."

Most commercial LEDs are made from crystalline semiconductors, such as gallium arsenide or indium phosphide, which glow when electricity flows through them. But there is increasing interest in making LEDs from organic (carbon-based) substances instead, as they would be easier and cheaper to manufacture.

So far, organic LEDs (OLEDs) have been made from electricity-conducting polymers that emit light, as well as from certain small organic molecules such as aluminium tris(8-hydroxyquinoline), or Alq3.

Thomson's team scattered their chromophore-like molecules through a matrix of Alq3 in an OLED. The idea was that these 'dopants' would capture energy from the matrix and convert it to light emission, determining the colour and efficiency of the device.

By tinkering with the molecular structures, Thompson and his colleagues fashioned green and orange chromophore OLEDs. These are not yet as efficient as existing devices, but the first prototypes in this field are usually improved by further work.

1. You, Y. et al. Fluorophores related to the green fluorescent protein and their use in optoelectronic devices. Advanced Materials 12, 1678?681 (2000).

Technology : Solar power goes organic

PHILIP BALL

Every day the Sun delivers to the Earth surface ten thousand times more energy than is needed to run the world. Converting sunlight to electricity could break our dependence on polluting fossil fuels for energy.

Unfortunately photovoltaic solar cells are currently too expensive for anything but small-scale domestic use. Now scientists at Bell Laboratories in Murray Hill, New Jersey, USA, have taken a step towards cheaper solar energy with a new, inexpensive organic photovoltaic device.

Existing commercial solar cells are made from the semiconductor silicon. The slices of silicon in these devices are often rejects from the microelectronics industry, but still the cells remain too costly for very large scale deployment. Thus only a few multi-kilowatt solar power plants exist in the USA, Japan and Europe, and they cannot make electricity as cheaply as traditional power stations fired by coal, gas or oil.

Some researchers are determined to bring the costs down by making solar cells better at capturing light and turning it into electricity. Another, perhaps more pragmatic, approach focuses instead on making moderately efficient devices from much cheaper materials or processes.

This is the philosophy pursued by J. Hendrik Schön and co-workers at Bell Labs. They have replaced silicon with pentacene? an organic (carbon-based) substance. Pentacene is a particularly promising organic semiconductor for solar cells because it absorbs sunlight and can conduct both the negatively and positively charged particles (electrons and holes) produced in the photovoltaic process.

The researchers?pentacene cells are sandwiches: a layer of pentacene sits between one electrode of transparent, semiconducting zinc oxide and one of platinum or another conducting material. The pentacene performs more efficiently if spiced with small amounts of bromine.

The best results were obtained for cells made of crystalline pentacene. These converted 4.5 per cent of incident white light into electricity. This may not sound very impressive, but costly commercial silicon cells do only twice as well.

But making single-crystal pentacene is not easy. So the researchers also manufactured this layer using vapour-phase deposition, they explain in Applied Physics Letters[1].

Photovoltaic solar cells made with this thin-film pentacene were only 2.2 per cent efficient. But such films can be laid down on plastic to create cheap, flexible devices that could be draped over large areas. Low efficiency could thus be offset by low material and manufacturing costs.

1. Schön, J. H., Kloc, Ch. & Batlogg, B. Efficient photovoltaic energy conversion in pentacene-based heterojunctions. Applied Physics Letters 77, 2473-2475 (2000).

Technology : Physicists squeeze laser light from silicon

PHILIP BALL

Italian physicists have taken a crucial step towards the creation of a silicon laser - the holy grail of optoelectronics? the marriage of electronic and light-based information technology.

Miniaturized solid-state lasers made from semiconducting materials liberated information technology from its reliance on electronics and magnetism. We can now use light to store and transmit information.

But electronic integrated circuits are carved in silicon and silicon refuses to emit light efficiently. The lasers that read CDs and send light pulses down optical cables are made from different, incompatible semiconductors such as gallium arsenide.

And gallium arsenide doesn't stick to silicon. So semiconductor lasers can easily be fabricated on silicon chips. This makes current optoelectronic technology cumbersome, a shotgun marriage of two unlikely partners.

If only silicon itself would emit light. An electrical current injected into gallium arsenide stimulates the release of energy as photons, particles of light. But in silicon the energy gets squandered in other ways.

Silicon's ability to emit light can be enhanced by cutting it into very small pieces. If the material is fashioned into wires, sheets or lumps measuring just a few nanometres (millionths of a millimetre) across, it begins to glow when electrically stimulated. Quantum mechanics, which takes over at very small sizes, relieves the factors that normally suppress the formation of photons.

Lorenzo Pavesi of the University of Trento in Italy and colleagues have taken advantage of these quantum size effects?to wring something close to laser-like emission from silicon, as they report in Nature[1].

Says Leigh Canham, a British physicist who was the first to see light being emitted from silicon as a result of quantum size effects, the work is "a major milestone in our attempts to develop silicon-based optoelectronics".

Pavesi team made nanoparticles?of pure silicon, just three nanometres across, by firing high-energy ions into silicon dioxide, in its mineral form, quartz. They gave the same treatment to a thin layer of silicon dioxide grown on a silicon chip, to show that the nanoparticles could be made on a chip.

Many researchers have shown light emission from silicon nanoparticles. But making laser light is something else.

In a laser, a whole horde of photons is conjured up at once by stimulated emission? The photons bounce back and forth between mirrors, liberating others on each pass, thereby amplifying the light pulse. Eventually all the photons escape in a very bright, focussed beam, all vibrating in step.

This light-amplified stimulated emission of radiation?(from which the acronym laser?derives) can also be induced by illuminating the lasing?material. Pavesi group found that when they directed a conventional ultraviolet laser onto their silicon nanoparticles, the particles emitted red and infrared light.

If the stimulated-emission process characteristic of laser action is taking place, a probe?laser beam of the same wavelength should gain in brightness when passed through the material. The researchers detected this telltale sign in their samples.

This does not in itself amount to true laser action, but it demonstrates that laser action could be possible from these specks of silicon.

1. Pavesi, L., Mazzoleni, C., Dal Negro, L., Franzò, G. & Priolo, F. Optical gain in silicon nanocrystals. Nature 408, 440-444 (2000).

Technology : It's a small, kinky world

They are the ultimate in electronic miniaturization: tube-shaped molecules of carbon, each scarcely wider than a filament of DNA, able to conduct electricity and to be bent, cut and moulded into circuit wiring or even into new electronic devices. They are called carbon nanotubes; and US physicists have now reported that they can be manipulated into genuine electrical circuits.

The idea that integrated circuits could be wired up using conducting carbon nanotubes has been much vaunted since their discovery in 1991. It was quickly appreciated that, since they have essentially the same structure as graphite, another form of pure carbon, nanotubes should, like graphite, be able to conduct electricity. Detailed calculations verified that some carbon nanotubes could indeed act like tiny metallic wires.

At present, wires for integrated circuits are carved from thin films of metals or semiconductors deposited on a silicon chip. But the standard lithographic techniques used by the microelectronics industry struggle to create features thinner than about one-fifth of one-thousandth of a millimetre -- 0.2 micrometres. Carbon nanotubes can be made 100 times thinner than this, and so might in principle permit a far higher density of wiring -- and so greater miniaturization.

The problem is finding a way to position objects this small. One solution, developed by researchers at Stanford University last year, is to grow the nanotubes directly onto the metal electrodes of the devices used in the circuit (see Nature 395, 878; 1998) [1]. Nanotubes can be grown from a carbon-rich vapour, like icicles condensing from winter air, and the Stanford method uses a catalyst to promote growth at the electrode.

Now Alan Johnson and colleagues from the University of Pennsylvania report in the journal Applied Physics Letters[2] that they can assemble circuits from preformed nanotubes. To manipulate components, the researchers use a device called the atomic force microscope (AFM). Originally conceived as an instrument for taking high-resolution images of the atomic-scale structure of surfaces, the AFM has also proved immensely useful for pushing molecules around on surfaces. It consists of a very fine needle tip attached to an arm which can be moved with great precision. Johnson and colleagues have used the tip as a kind of finger to gently nudge nanotubes around on an oxidized silicon wafer.

They were able to place nanotubes on top of one another, cut them into shorter sections, and sweep away the fragments and unwanted tubes. The researchers decided to investigate in detail what happens when nanotubes cross, so that one lies kinked over the other. They laid down metal contacts at the ends of the tubes, so that they could apply a voltage and measure the current.

They found that this simple tube junction acted like a device called a unnel junction? in which electrons leak through a poorly conducting region between two conductors. They suggest that the deformation of the upper tube, as it passes over the lower one, causes this localized decrease in conductivity by disrupting the atomic structure of the tube.

Kinks in nanotubes, then, might be used to modify their electronic properties, and perhaps to uild?device-like structures into the very wires themselves. If methods can be found for generating such kinks in a controlled way -- and the AFM will surely be a candidate tool for making them as well as moving them about -- then we might look forward to microelectronics shrunk to molecular dimensions and based not on silicon but on carbon.

1. Kong, J., Sog, H.T., Cassell, A.M., Quate, C.F. & Dai, H. Synthesis of individual single-walled carbon nano-tubes on patterened silicon wafers. Nature 395, 878 (1998)

2. Lefebvre, J., Lynch, J.F., Llaguno, M., Radosavljevic, M. & Johnson, A.T. Single-wall carbon nanotube circuits assembled with an atomic force microscope Applied Physics Letters 75, 3014-3016 (1999).

Technology : The molecular torch

PHILIP BALL

The optical microscope, pioneered by the Dutchman Antony van Leeuwenhoek in the seventeenth century, transformed scientific discovery even more than Galileo's telescope. Through its lens, scientists have seen bacteria and viruses, as well as chromosomes and the many other tiny structures that make up our cells. Optical microscopes are now regarded as pretty blunt probes, compared with instruments such as electron microscopes -- but they are far from obsolete.

As researchers in Germany now report in Nature [18 May 2000][1], single glowing molecules can illuminate samples in an optical microscope. With such a tiny light source, the new device should be capable of revealing individual molecules. Other, non-optical microscopes can already do this, but light-based methods bring certain advantages -- particularly to the study of living cells.

The new instrument, described by Vahid Sandoghdar and colleagues at the University of Konstanz, Germany, is a development of a technique called scanning near-field optical microscopy (SNOM). This method avoids a problem that restricts the resolution of optical microscopes: a light beam cannot be focused to a point finer than its own wavelength -- the 'diffraction limit'.

The diffraction limit of visible light is several hundred nanometres (millionths of a millimetre). Individual cells are typically larger than this by a factor of ten or more, so they can be studied. But small molecules, less than a nanometre across, are much too small to view with conventional optical microscopy.

Near-field optical microscopy beats the diffraction limit by using a light source so small that it does not need focusing. This source is placed very close to the sample, so it only illuminates an area about the size of the source. The source is then scanned across the sample, lighting it up like a roving torch beam to build up an image, little by little.

How are the tiny light sources needed for SNOM made? One way is to pull out a hot glass optical fibre into a conical tip, and then to coat all but the very end with metal. Light inside the fibre emanates from this exposed tip. This approach has produced sources no more than 100 nanometres or so across, which permits optical microscopy with comparable resolution. But the best systems run aground at around 50 nanometres, partly because metal films are leaky 'masks' over this distance and partly because it is hard to make fibre tips any finer.

Sandoghdar's team have now made a tapering optical fibre that ends with a single molecule, which lights up (fluoresces) when illuminated by laser light in the fibre. So the tip becomes essentially a single-molecule torch, and its fluorescent emission illuminates the sample.

The fibre tip itself is much wider than this single molecule. To this tip, the researchers glued a tiny organic crystal, in which a handful of molecules of the fluorescent substance 'terrylene' were dispersed. These terrylene molecules each take up a random position in the organic host material, so they absorb laser light at a slightly different frequency. This means that the laser can be tuned to excite just one of the terrylene molecules.

Using their single-molecule probe, Sandoghdar and colleagues have taken images of a micro-patterned array of metal islands on a glass slide. The islands, about 500 nanometres across, could be seen in the image taken with the light from a single molecule. By tuning the excitation laser to light up molecules right on the edge of the tip (and so nearest the sample), the researchers expect to be able to achieve much higher resolution, even picking out individual molecules.

1. Michaelis, J., Hettich, C., Mlynek, J. & Sandoghdar, V. Optical microscopy using a single-molecule light source. Nature 405, 325-328 (2000).

Technology : Little lasers

PHILIP BALL

Lasers, once hailed as an invention in search of an application, have now found homes ranging from compact disk players to supermarket checkouts. In many of these applications the lasers are miniaturized, fitting comfortably onto a pinhead. A new kind of laser that is no bigger than a bacterium and can be made simply by mixing chemicals in a beaker is now described in the journal Applied Physics Letters[1].

Laser light differs from ordinary light because the wave-like oscillations of the light rays are all in step. The light is emitted from a substance that has been 'excited' -- given excess energy, which it releases as light. The regimentation arises because some light itself stimulates the emission of more light, which is in step with the stimulus. The light is confined in a chamber with mirrors at either end. Bouncing back and forth between the mirrors, the light stimulates ever more emission with each pass. Eventually the light bursts out in one coherent beam through one of the mirrors, which is designed to be slightly transparent.

In most miniaturized lasers, the excitable material is generally a tiny brick-shaped block of semiconductor which emits light when a current is injected into it. These devices are typically a few tenths of a millimetre long -- which sounds small, but is immense compared with the size of electronic components on a silicon chip. In the past decade, a new breed of much smaller semiconductor lasers has been created. Called microlasers, they are typically just a few thousandths of a millimetre across.

Microlaser mirrors are highly reflective and consist of a stack of thin layers of different semiconductors. These stacks, called Bragg reflectors, can reflect more than 99 per cent of the light falling on them within a certain range of wavelengths.

As one might imagine, these microscopic multi-decker sandwiches are hard to make. But Hui Cao and colleagues from Northwestern University in Illinois, USA, now describe a kind of microlaser put together in a flask of chemical reagents. They use a simple chemical procedure to make particles of the semiconductor zinc oxide that are just a few nanometres (millionths of a millimetre) in size. Under the right conditions, these 'nanoparticles' clump together into aggregates ranging from several hundred to a few thousand nanometres across.

Yet these clusters don't have the beautiful regularity of Bragg reflectors. Quite the opposite: they are a random jumble of nanoparticles. But this is precisely what Cao and colleagues intend. The nanoparticles are so small that they scatter short-wavelength (ultraviolet) light, just as tiny water droplets in clouds scatter sunlight. If these 'scattering centres' are arranged in a disorderly manner, the scattering becomes so extreme that the light can't make progress in any direction -- it gets stuck.

Within the nanoparticle clusters prepared by Cao and colleagues, localization of light can create 'optical cavities' that act like the mirrored chambers of a microlaser. The zinc oxide semiconductor is stimulated into laser action by 'pumped' light from another laser beam. The researchers fired short-wavelength light from a conventional benchtop laser at their clusters, and find that they emit ultraviolet light with a very narrow range of wavelengths -- a characteristic signature of laser light.

Cao and colleagues say that their ultraviolet microlaser is much easier and cheaper to make than conventional Bragg-reflector devices. One drawback, however, is that its properties are much harder to control as the emission wavelengths are randomly generated. Different clusters emit light at different wavelengths, depending on the size of the 'cavity' created by the random disposition of the constituent nanoparticles.

1. Cao, H., Xu, J. Y., Seelig, E. W. & Chang, R. P. H. Microlaser made of disordered media. Applied Physics Letters 76, 2997-2999 (2000).

January 21, 2000 / New York Times / Friday Business / Financial Desk

A Clinton Initiative in a Science of Smallness

By JOHN MARKOFF

The Clinton administration plans today to announce an ambitious program to accelerate basic research in the field of nanotechnology, the design and fabrication of devices of ultramicroscopic size.

Nanotechnology is widely considered an extremely promising area of science and engineering, but it has realized only limited commercial success to date.

Today, in a speech at the California Institute of Technology in Pasadena, President Clinton will stress the importance of expanding basic research in both the physical and biological sciences. As part of the speech, he will announce plans to ask Congress to finance a National Nanotechnology Initiative to encourage basic research in the field.

The president will set out these ''grand challenges'': Shrinking the entire contents of the Library of Congress into a device the size of a sugar cube; assembling new materials from the ''bottom up'' -- from atoms and molecules; developing ultralight materials that are 10 times as strong as steel; creating a new class of computer chip millions of times as fast as today's Pentium 3; doubling the efficiency of solar cells; using gene and drug-delivery technologies to detect and target cancerous cells, and developing new technologies to remove the smallest contaminants from water and air.

The initiative will double federal spending in the field over the next five years. The plan calls for an increase in nanotechnology research spending to $497 million in the coming fiscal year, about 70 percent of which will go to university scientists for basic research.

Thomas A. Kalil, special assistant to the president for economic policy, said: ''Nanotechnology is a perfect example of the kind of investments that President Clinton and Vice President Gore believe are necessary for America's future. It's long term, high risk and high payoff.''

Nanotechnology -- broadly defined as the ability to manipulate and move matter -- is rapidly developing as a promising approach to a wide range of sciences and technologies. For example, researchers at both corporations and universities have made significant strides in the last year toward building computers that would be several orders of magnitude smaller and more powerful than today's silicon-based machines.

Moreover, nanotechnology is believed to have great potential in biomedicine in applications ranging from improved drug delivery to disease detection.

In the world of mechanical devices, nanotechnology has already created billion-dollar markets for devices like ink-jet printer heads and accelerometers for automobiles. But researchers are optimistic about even bigger payoffs. For example, researchers believe they are on the track of new materials that are as much as 10 times as strong as steel, yet weigh only a fraction of it.

Currently the National Science Foundation, the Pentagon, the Energy Department, NASA, the Commerce Department and the National Institutes of Health are all financing nanotechnology research. The National Nanotechnology Initiative calls for increasing spending by these agencies -- as much as 400 percent in the case of NASA -- in next year's budget.

There has been an explosion of nanotechnology-oriented research proposals coming from university campuses in the last year, a government official said, and it has only been possible to finance a fraction of them under the current spending limits.

Spending under the new program will be broken down into financing long-term fundamental research; support for grand challenge efforts; the creation of new research centers; the establishment of a research infrastructure, and the study of ethical, legal and societal implications of nanotechnology.

Organizations mentioned in this article:

Related Terms:
Science and Technology; Finances; Budgets and Budgeting; Law and Legislation; Research; Nanotechnology; Engineering and Engineers; Biotechnology

Clinton seeking multi-billion-dollar boost in science, research funds

CNN January 21, 2000
Web posted at: 12:50 PM EST (1750 GMT)

WASHINGTON (AP) -- President Clinton will seek a $2.8 billion boost in basic scientific and medical research to spur economic growth and enhance health for Americans in the 21st century, the White House says.

In a speech today at the California Institute of Technology, Clinton was announcing that his administration's budget for fiscal 2001 would include a major new investment in the 21st Century Research Fund aimed at boosting research in several critical fields, including cancer, diabetes and AIDS, and promoting development of super-fast computer technology.

While in the Los Angeles area, Clinton also planned to host a pair of fund-raising events to benefit the Democratic National Committee. He may also get in a round or two of golf.

In recent days, Clinton, administration officials and allies on Capitol Hill have been disclosing pieces of the 2001 budget that the president will present to Congress on Feb. 7. Details of Clinton's research-investment proposal were made available by White House officials who commented on condition of anonymity.

Clinton will tell his Cal Tech audience that a new investment in basic research of the magnitude he proposes is an important step in assuring U.S. prosperity in the 21st century and will lead to longer and healthier lives.

Major elements of the new proposal include:

• A $1 billion increase in biomedical research at the National Institutes of Health.

• A $675 million increase in spending for the National Science Foundation. A White House official said, that if approved, the new spending level will "double the largest dollar increase ever in the history of the foundation."

• $475 million for a nanotechnology initiative. This could lead, the White House official said, "to the ability to store the contents of the Library of Congress in a device the size of a sugar cube." Nanotechnology is a new field that proponents hope will lead to the development of atom-sized devices and machines.

Clinton to request funding increase for 'bioenergy' product research

CNN January 14, 2000
Web posted at: 2:17 PM EST (1917 GMT)

WASHINGTON (AP) -- President Clinton wants a $243 million increase in funding next year for developing technologies that turn trees, plants and animal waste into energy and environmentally friendly products.

The president's proposed 2001 budget will ask Congress for a total $439 million to fund research and grants to aid the production of "bioenergy" and other products, such as plastics and chemicals, from agricultural waste.

The plan, outlined in a White House document obtained Thursday by The Associated Press, follows up on an August executive order creating an interagency council to promote bio-technologies and, hopefully, reduce U.S. oil demand and protect the environment.

It would go beyond the $196 million program Congress approved this year for developing new biomass-based fuels by also focusing attention on other new bioproducts such as feedstocks and consumer goods.

Roger Ballantine, an adviser to the president on environmental issues, pointed to an announcement by Cargill Inc. and Dow Chemical Co. that they would begin producing plastics made from corn rather than petroleum as a harbinger of things to come.

"It's going to revolutionize both the farming industry, in that you're talking about another huge source of demand for farm products -- but even more specifically the impact it can have environmentally," Ballantine said.

A spokesman for GOP Sen. Dick Lugar of Indiana, chairman of the Senate Agriculture Committee, said new congressional authority may be needed for some of what Clinton wants to do. Still, he welcomed the president's commitment to the promotion of bioenergy.

"There have been major breakthroughs in the technology," said Andy Fisher, Lugar's spokesman. "So this is sort of the right time to strike. The full eco-balance of the equation is far better than anything we've seen before."

Lugar has his own legislation promoting "biomass" development that would authorize $300 million over six years for research. Approved in the Senate, it has received a cooler reception in the House.

Clinton's plan includes a request for $49 million for the Energy Department's research into cellulase systems to break down woody and grassy crops into feedstocks and to underwrite development of new technologies to develop new consumer products.

It also includes $194 million for Agriculture Department initiatives. A large chunk, about $150 million, would be for incentive payments through the department's Commodity Credit Corporation to bioenergy producers that buy more farm commodities to expand their production.

November 1, 1999 / New York Times / Monday Business/Financial Desk

TECHNOLOGY; Computer Scientists Are Poised For Revolution on a Tiny Scale

By JOHN MARKOFF

Scientists at a variety of elite laboratories around the country are sharing a growing sense that they are on the brink of a new era in digital electronics. It will usher in a world of circuits no more than a few atoms wide, with a potential impact on computing, in terms of speed and memory, that may be too profound to fathom.

It was only in July that a group of researchers at Hewlett-Packard and the University of California at Los Angeles reported that they had successfully fashioned rudimentary electronic logic gates -- a basic component of computing -- that were the thickness of a single molecule. Now other groups are preparing to announce that they have succeeded in creating other basic computing components at this ultramicroscopic scale, known as molecular electronics.

Researchers at Yale and Rice Universities, for example, plan to report in the journal Science in a few weeks that they have taken an important step past the Hewlett-U.C.L.A. work. In the July demonstration, the molecular gate could be made to move into open or shut positions, but could not be switched back again. But the Yale-Rice team says it has created molecular-scale switches that can be repeatedly opened and shut -- a necessary step in representing zeros and ones, the basic binary signals used in the circuitry of digital transistors.

And now Hewlett-Packard scientists say they have recently taken an important step toward creating rows of conductive wires that are less than a dozen atoms across -- a crucial part of hooking together the molecule-sized switches that could one day result in computers vastly faster than today's.

The rapid sequence of breakthroughs is giving the researchers a new sense of confidence. ''We're on the scent, and we know the fox is out there,'' said Stan Williams, a Hewlett-Packard physicist who is a pioneer in molecular electronics.

According to the buzz in this research community, meanwhile, other laboratories are making progress on a number of fronts, working under top-secret conditions. One of these labs is said to be working on a molecular device capable of holding random-access memory, or RAM.

If molecular memory devices could be constructed, they might offer vast storage capabilities for just pennies in cost. One near-term application might be to permanently store an entire DVD-quality movie in a space much smaller than a conventional semiconductor chip.

As an applied science, molecular electronics would begin at a minute scale far beyond the theoretical boundaries of the conventional technology of silicon transistors.

Today's silicon-based microelectronic devices have a minimum size between electrical components of 0.18 micron (about one-thousandth the thickness of a human hair) and could potentially go as small as 0.10 micron. That would be 100-billionths of a meter, or 100 nanometers.

But in molecular electronics, the smallest components may be able to shrink to one-hundredth that size -- a single nanometer. The difference could mean chips exponentially more powerful than anything of a comparable size today or computing devices unimaginably tiny by contemporary standards.

The recent rapid pace of advance has led to a palpable sense of mission among a small group of physicists, chemists and computer designers, who until recently were viewed as impractical dreamers by much of the computer industry.

''In two to five years, you will begin to see functioning circuits which are of recognizable utility,'' said John C. Ellenbogen, a molecular electronics researcher at the Mitre Corporation, a research center for the military and private industry.

Such optimism leads a number of researchers to believe that rapidly cascading advances in molecular-scale science may soon constitute what economists refer to as a disruptive technology -- one that changes basic industrial assumptions, just as the transistor did in replacing the vacuum tube during the 1950's, and as integrated circuits overtook individual transistors during the 1960's. Some molecular electronics researchers envision an entirely new industry, perhaps within the next decade.

The consequences of such a revolution would be immense and possibly destabilizing for the world's semiconductor industry. Although the chip industry now believes that it sees a path at least until 2014 for making ever-smaller solid-state silicon devices, the cost of the manufacturing systems to make the chips is enormous -- and continuing to mount with each new chip generation.

Today's semiconductor chips are made in multibillion-dollar fabrication plants -- or ''fabs'' -- that use light waves to etch successive layers of circuitry on a silicon substrate. It is an expensive process, in part because of the high cost of creating and maintaining the ''clean rooms'' required for avoiding contamination by dust. But researchers in molecular electronics are optimistic that they will be able to use much less finicky methods by creating chemical reactions that ''self-assemble'' vast numbers of molecular-scale circuits at infinitesimal cost.

''This should scare the pants off anyone working in silicon,'' said Mark Reed, a Yale University chemist, who is co-author of the forthcoming Science article and co-leader of a related memory project to be announced Dec. 6 at the International Electron Device Meeting in Washington. ''It will be dirt cheap and it will create a discontinuity.''

A colleague in the field agrees. ''If you can make computers as easily as photographic film, then a lot of companies are going to be wondering what they're doing with their $15 billion fabs,'' said James R. Heath, a U.C.L.A. chemist who is part of the Pentagon-financed Hewlett-Packard-U.C.L.A. research team that demonstrated molecular logic gates last summer.

The vision of a new industry has captured government and corporate attention. The Clinton administration is now considering the possibility of a National Nanotechnology Initiative as early as next January to set up financing and help organize diverse research activities in nanotechnology -- a range of manufacturing technologies that begin at the scale of individual molecules. Moreover, a number of computer and semiconductor companies, led by Sun Microsystems and Motorola, have been quietly meeting with scientists to discuss the formation of an industry consortium to seek commercial applications for molecular electronics.

And yet, researchers acknowledge that so far they have taken only the first baby steps toward the larger challenge of building molecular-scale computers. No one, for example, has figured out how to interconnect billions and billions of molecular switches with wires 11 atoms in diameter.

''It feels like we're a year before the invention of the transistor and we're asking: 'What does solid state look like?' '' said Paul Saffo, a researcher at the Institute for the Future who has tracked the development of new technologies.

And there is a general agreement that if such systems are to be assembled into workable computers, it will require radically new architectures alien to today's semiconductor-based computers.

At Hewlett-Packard, at the Massachusetts Institute of Technology's Laboratory of Computer Science and at Mitre, computer scientists are beginning to explore computer architectures that are far more fault tolerant than today's microelectronic computers and whose structures resemble biological systems.

Manufacturing might involve assembling trillions of circuits and then identifying and mapping out the bad ones -- much as faulty sectors are declared off limits in today's disk drives.

''We will try to program with what we've got,'' said James Tour, a molecular scientist at Rice University. ''It's a very biological approach: everyone's brain is the same, but the pathways are all unique.''

Much of the research financing in this field now comes from the Pentagon's Defense Advanced Research Projects Agency. ''We've built this entire program on the idea of thinking differently,'' William Warren, a program manager at the agency, said. ''We don't want to be standing on the shoulders of silicon.''

That is why the recent first steps toward eventual self-sufficiency have created such excitement in the molecular computing research community, a group that for years had a consistent vision but no empirical results.

''All of us were constantly on the defensive,'' Mr. Ellenbogen, the Mitre researcher, recalled. ''Although we believed in some rational way this was the way to go, among ourselves we were continually forced to reassure ourselves that we weren't crazy.''

Japanese invent world's tiniest robot

CNN July 13, 1999
Web posted at: 5:04 p.m. EDT (2104 GMT)

(CNN) -- It's people versus robots in the latest "Star Wars" movie, as Jedi knights battle the mechanized minions of the galaxy's Dark Side.

But in Japan, robots aren't the enemy. They are the good guys. They are also getting smaller, a lot smaller.

Scientists in Tokyo have invented what may be the world's tiniest robot, measuring just 10 millimeters long and weighing less than half a gram.

Researchers hope to use the micro-robots to repair equipment in nuclear and thermal plants. The device could maneuver in tight crevices or lock onto damaged parts.

The robots, which can crawl into the tiniest gaps around bundles of pipes, are expected to speed up inspection and repairs at electric and nuclear power plants because they can be sent in while the plants keep running.

Scientists are working to add new functions to them so the robots can climb up and down a pipe while connected to other machines. They also plan to develop robots with motors and problem-detecting sensors.

U.S. government engineers have developed miniature surveillance robots that can hover around a room. And NASA engineers are working on a "spacecraft on a chip," says Barry Hebert, manager of micro- and nano-technology development at NASA's Jet Propulsion Laboratory.

"That means miniaturizing every part of a spacecraft, from brains to instruments to devices," he says. "Right now we've got systems on a chip and right now we're putting the components together to do that."

But for now, the Japanese may hold the record for the tiniest robot in operation.

The idea for tiny robots began 10 years ago as a cooperative research project between the government and Mitsubishi Electric Corp., Sumitomo Electric Industries Ltd. and Matsushita Research Institute Tokyo, Inc. under the government's 25 billion yen ($206 million) "micro-machine" project, said Koji Hirose, spokesman for the Ministry of International Trade and Industry.

Despite the big plans, the micro-machines are still years from widespread use.

July 1, 1999, Thursday / New York Times / Circuits

WHAT'S NEXT; A Stay of Execution For the Silicon Chip

By PETER WAYNER

SCIENTISTS at Lucent Technology's Bell Labs have examined the future of the silicon-dioxide-based transistor that is used in billions of chips and have pronounced the technology both half full and half empty.

In a report issued last week, the scientists said that one fundamental barrier to small chips wasn't as absolute as scientists had thought.

Silicon dioxide was supposed to be nearing the end of its usefulness as a main component of microchips in 3 to 6 years, but the Lucent team has shown that it should remain viable for at least 12 more years (the half-full part). After that, however, it's finished -- and this time the scientists really mean it (the half-empty part). The team, led by David Muller, published the results of its work in the British journal Nature.

Silicon dioxide is usually applied in thin layers on chips because it's an insulator. Pure silicon wafers are a semiconductor of electrical signals, but mixing silicon with oxygen in silicon dioxide cuts off the flow of electrons and lets it act as an insulator.

This silicon dioxide insulator is a crucial part of transistors because it allows one wire to get close enough to another wire to act as a switch without shorting out. As companies try to pack more and more transistors, a type of switch, on a chip, they need to make the silicon dioxide layer as thin as possible. That layer is sometimes called the ''gate oxide.''

''In the typical transistor today, the gate oxide is 25 atoms thick,'' said Greg Timp, a member of the research team. ''Even that is thinner than people expected.''

Physicists have long wondered just how closely they can slice silicon dioxide. ''They thought we would have to stop at 10 atoms or 8 atoms,'' Dr. Timp said. ''We've managed to push this down to 5 or maybe 4.''

The team of scientists came to this conclusion after trying two different experiments. In the first test, they created silicon wafers that were covered with several very thin layers of silicon dioxide. Then they used a scanning electron microscope and focused its beam of electrons down to the width of an atom.

The beam of electrons was many times more powerful than a typical current on a computer chip, so it was strong enough to flow through the silicon dioxide. The physicists used it to study the electrical structure of the atoms. In the electron beam, the layer appeared about as transparent as an insect stuck in amber looks when examined with a flashlight.

The team looked at column after column of atoms. ''You fire the beam off the sample, and it just hits one column at a time,'' Dr. Muller said. ''Then you move the beam over to the next column, and you can map out the profile.''

The team found that the silicon dioxide layer needed to be four or five atoms thick to act as an insulator. With thinner layers, quantum effects led to the leakage of electrons across the silicon dioxide layer, shorting out the circuit. The thinner the layer, the more electrons leaked.

The team also tried building small transistors with more and fewer than four or five atoms in the dielectric layer and found that the behavior matched the results they had predicted. To be practical, the layer needs to be a little thicker than the theoretical limit of four atoms thick.

That pushes back the timing of the doom expected for the silicon chip. The Bell Labs team predicts that silicon dioxide will continue to be a useful insulator through 2012 if chip manufacturers continue to shrink the size of transistors at the current rate. At that point, the chip designers will be down to layers five atoms thick and won't be able to shave more atoms to save space.

Randy Isaac, a research vice president at International Business Machines, said the new work was right in line with some of I.B.M.'s own research. Still, he predicted that I.B.M.'s teams would hit the four- to five-atom barrier well before 2012, perhaps as early as 2005, but was optimistic that faster chips would continue to emerge even after that.

''The key message is for 30 years, the evolution of the transistor has been guided by a recipe for miniaturization, but you cannot reduce that thickness forever,'' Dr. Isaac said. ''So we'll turn to other innovation. We'll use other techniques.'' He cited some of I.B.M.'s latest innovations, like using copper wiring on chips and building three-dimensional transistors, with silicon dioxide on two sides of the transistor. Each solution he suggested tweaks some assumptions of chip design. Chip makers have avoided using copper for wiring because it can contaminate other parts of a chip, but I.B.M. recently found a way around that problem.

Dr. Muller and Dr. Timp suggested that some research would continue to focus on a silicon dioxide replacement. One job of the insulator in a transistor is to act like a common device known as a capacitor, which can store energy in the form of an electrostatic field. Other chemicals do a better job at this, and replacing silicon dioxide with them may make chips faster without shrinking the size of the transistors. Both scientists caution, however, that those other chemicals may have other flaws.

Ralph Merkle, a Xerox nanotechnology specialist at the Palo Alto Research Center, said more far-fetched solutions might turn out to be practical. ''Some of the proposals kicking around in a half-formulated state involve using electron spin or other very small structures that somehow allow you to shrink the basic device size,'' he said.

Dr. Isaac is optimistic. ''History has shown that if something can be done, someone will find a way to do it,'' he said. ''We'll just have to find different ways of implementing the transistor.''

A taste of the future: the electronic tongue

CNN January 28, 1999
Web posted at: 11:21 a.m. EST (1621 GMT)

AUSTIN, Texas (CNN) -- Researchers at the University of Texas are developing an electronic tongue that they hope will someday be able to taste the differences in a variety of liquids, from orange juice to blood.

But can an electronic tongue mimic the sophisticated palates of wine tasters? Eventually, its developers say, it may come close.

With wine, for example, the tongue changes colors depending on how sweet or sour the vintage is.

The electronic tongue contains tiny beads analogous to taste buds. Each "bud" is designed to latch onto specific flavor molecules and change colors when it finds one, be it sweet, sour, bitter or salty.

The buds are housed in pits on the surface of the tongue itself, which is made of silicone.

"Each one of these pits looks like a little pyramid, and it's just the right size that we can take one of these taste buds ... and nestle it down inside," says Dean Neikirk, a University of Texas computer engineer.

Researchers hope the electronic tongue can be used by industry to ensure that beverages coming off assembly lines are uniform in flavor.

They also plan to go beyond the four tastes of the human tongue and use the device to analyze such substances as blood or urine, or to test for poisons in water.

Some day, says chemist Eric Anslyn, the tongue might speed up blood analysis by testing everything from cholesterol to medications in a person's bloodstream, all at the same time.

But the developers have a way to go before achieving their vision. So far, the tongue can only tell the difference between white wine and white vinegar.

World's smallest 'pen' draws tiny circuits

WASHINGTON (Reuters) -- Researchers said on Thursday they had created the smallest pen, and said its tiny nub could be used to "write" microscopic electronic circuits.

They used their instrument to inscribe extremely fine lines, just a few molecules thick, onto gold.

Writing in the journal Science, the team at Northwestern University in Chicago predicted that their method, which they called dip-pen nanolithography, could be used in microfabrication, nanotechnology, and molecular electronics.

"This should open up many ways to explore the nano-world of electronics based on molecules," Chad Mirkin, a chemistry professor at Northwestern who directed the study, said in a statement.

The device works on the same principle as an old-fashioned quill pen. But its "ink" is made from chemicals known as alkanethiols, and the "paper" is gold.

The "pen" is an atomic force microscope, or AFM, which is often used in laboratories working on tiny devices.

"It's engineering, but when you get down to the 'nano' scale, it's really chemistry," Mirkin said.

He would like to perfect the pen so that it works more like a fountain pen, saving the need to continually dip into the "ink."

"This technique will be even more technologically useful once we convert our dip-pen to a fountain pen, and once we can draw multiple lines in parallel rather than serial fashion," Mirkin said.

He sees immediate uses, for instance, on nanochips used in computers.

"Suppose I have a computer chip that will form the basis for a chemical sensor, and I need to put onto its nanocomponents some chemical that will tell me whether or not some chemical agents are around," he said.

"I could use this type of technique to do that. I can go in and just paint those components with different types of molecules."

Researchers make a 'machine' out of DNA

CNN January 13, 1999
Web posted at: 3:10 PM EST

(AP) -- Scientists have made a moving part out of a few strands of DNA, a step toward building incredibly tiny "machines" that could someday perform intricate jobs like building computer circuits and clearing clogged blood vessels in the brain.

The hinge-like part, which bends on cue, is just four-ten-thousandths of the width of a human hair.

The new work isn't the first time scientists have turned chemical compounds into moving parts. But previous examples have been hampered by their floppy nature. The DNA device, however, is particularly rigid and executes motions 10 times bigger, lead researcher Nadrian C. Seeman said.

The device was made by joining two double-stranded DNA spirals with a bridge of DNA. When it's exposed to a particular chemical solution, part of the structure bends.

The findings were reported in Thursday's issue of the journal Nature by Seeman and colleagues at New York University. The team hopes to eventually build other moving parts using DNA, including "arms" and "fingers" that someday could be mounted on a micro-robot.

The work is the latest twist in the fledgling field of nanotechnology, or technology at an atomic scale. "This is a very beautiful demonstration of construction at that scale of a device that's actually functioning," said Daniel T. Colbert of Rice University's Center for Nanoscale Science and Technology.

However, Colbert said scientists are still decades away from creating any useful machines in nanotechnology. "We're kind of in the children's playtime toddler era of doing this. We've been thrown some blocks and Legos and Tinker Toys," he said. "We're just kind of picking them up and trying to assemble things out of them that can perform something useful."

K. Eric Drexler of the Institute for Molecular Manufacturing in Los Altos, Calif., agreed that Seeman's device is too cumbersome to be useful. But he said further development may lead to a practical device.

05/27/99 USA TODAY

Technology spells MEMS in future

By John Yaukey, Gannett News Service

Chemistry Nobel laureate Richard Smalley was once asked what field he would enter if starting over as a freshly minted Ph.D.

Without a pause, the Rice University professor launched into a prophetic description of the coming age of Lilliputian engineering.

"We're talking about the miniaturization of everything you can imagine," Smalley said. "Eventually, we will be designing tiny devices so that every atom is there for a particular reason."

Picture dexterous probes doing surgery through pinhole slits; microscopic drug dispensers planted in the body to deliver optimal doses at the perfect time; lasers peering into single cells to witness individual molecules carrying out the biochemical chores of life; credit card-sized chips capable of analyzing thousands of drug candidates for specific chemical reactions at once; transistors shrunken so trillions, instead of millions, fit on a single computer chip; electronic tweezers capable of plucking individual atoms; sensors so small and receptive they feel the pull of the moon or identify the vibrations and movements of military vehicles 100 miles away.

History is a graveyard of futuristic visions that fell flat.

But scientists and engineers across a spectrum of disciplines agree that the ability to miniaturize everything from microchips to motors will define the next technological age the way transistors and chips have come to characterize the present era.

Vision vs. feasibility

What makes this so compelling i