About Nano Technology

CNST releases inaugural version of nano@illinois research faculty handbook

2011-12-20T10:09:00.000-08:00

The Center for Nanoscale Science and Technology (CNST) released the inaugural version of the nano@illinois Research Faculty Handbook, featuring information on more than 150 U of I nanotechnology researchers and collaborators and also highlights some of the leading micro and nanotechnology laboratories and federally-funded multidisciplinary centers.

"In recent years, nanotechnology research has taken center stage at Illinois, with more than 150 researchers engaged in micro and nanotechnology research at the campus. Prior to the development of the handbook, it was a challenge to know who was involved in nanotechnology, but not anymore," said Irfan Ahmad, executive director of the Center for Nanoscale Science and Technology (CNST), and acting assistant dean for research for the College of Engineering. "The revised version of the handbook is being distributed campus- and nation-wide. "It has already stimulated new cross-campus partnerships."

"When we set out to establish CNST in 2001-02 in collaboration with colleagues at the Micro and Nanotechnology Laboratory, the Coordinated Science Laboratory, and the Frederick Seitz Materials Research Laboratory, we had envisaged CNST to be a clearing house for nanotechnology," said Ilesanmi Adesida, dean of the College of Engineering, the CSNT founder, and a current co-director. "This handbook accomplishes just that and much more; it will go a long way in further raising the profile of nanotechnology researchers at Illinois."

"We had always envisioned this handbook to be a resource for faculty researchers, graduate students, campus administration, industry, and state and federal agencies. The release is a culmination of these efforts packaged in a nicely developed reference handbook," said Rashid Bashir, director of Micro and Nanotechnology Laboratory who serves as a CSNT co-director.

"While reviewing the inaugural issue of the handbook, I was impressed at the way the information was structured for maximum benefit, while highlighting the research thrusts and faculty college and departmental affiliations," said Jozef Kokini, associate dean of Research, College of Agricultural, Consumer, and Environmental Sciences.

A PDF of the nano@illinois Faculty Handbook can also be downloaded here. A limited number of hard copies can be requested by sending email to nanotechnology@illinois.edu; additional copies are available at cost.
Source: University of Illinois

Nano sunscreen warnings won't be mandatory

2011-07-20T06:16:00.000-07:00

The Government is set to disappoint consumers who are worried about the use of nanotechnology in sunscreens, with documents obtained by PM showing the Government will not opt for mandatory labelling.
Nanotechnology opens up a new world of innovation and technological breakthrough, but also raises new safety considerations because compounds behave differently when they measure just billionths of a metre.
In October 2008, a NSW parliamentary inquiry noted that the risks of nanoparticles in sunscreen were still being investigated and it recommended sunscreens containing nanoparticles be labelled accordingly.
But such a ruling would require a change to federal laws, and the Federal Government is yet to respond to the call for mandatory labelling.
Documents obtained by PM spell out the Australian Government's position, as developed by a working group for the Department of Innovation.
The documents provide a general statement in response to labelling for any purpose: "At this early stage of use of nano products, labelling for informed choice should not be supported."
That advice was distributed at the Nanoproduct Labelling Meeting, convened by the Department of Innovation in November last year, along with a statement on the labelling of sunscreens and cosmetics specifically.
The department's advice is that nanoparticles cannot be reliably measured, and the safety concerns are dismissed: "...it would not be informing consumers of any hazard nor is it technically feasible to enforce at present."
The documents were provided to lobby group, the Friends of The Earth, after a freedom of information request.
Nanotechnology campaigner with Friends of the Earth, Elena McMaster, questions why the Government is yet to announce a position publicly, which she says is "very nervous about nanotechnology".
The question over the hazards of rubbing nanoparticles of titanium dioxide and zinc oxide into the skin is still a controversial one.
They are the chemicals which reflect UV radiation, but in nanoparticle form they absorb it, setting off a reaction which releases elements which can alter DNA.
The Australian regulator, the Therapeutic Goods Administration, says the current weight of evidence suggests nanoparticles in sunscreen do not reach living skin cells.
But a recent article in the Australasian Journal of Dermatology says nanoparticle sunscreens should be labelled because some recent studies suggest nanoparticles go deeper into the skin than previously thought.
The long-term effects of rubbing nanoparticles on skin are also the subject of an ongoing study by the CSIRO.
Ms McMaster says the Government's position ignores warnings from scientists.
"Our Federal Government is simply sticking its head in the sand and refusing to do anything," she said.
"What Friends of the Earth is advocating for is labelling of nanoparticles in sunscreens or cosmetics. So this would allow consumers to make up their own mind about whether they use a product containing nanomaterials or not."
She says if the Government will not or cannot regulate the area, it should ban the sale of sunscreens containing nanomaterials until the science is more conclusive.
"That's the bottom line for us. If we can't regulate to ensure safety we should be instituting a moratorium."
Some scientists and dermatologists are also calling for mandatory labelling of nano-sunscreens.
The cosmetics industry also wants the Federal Government to act, but for a very different reason.
Craig Brock, the policy director for ACCORD - which represents the cosmetics industry in Australia - says the industry wants to be on a level footing with the European industry, which will have mandatory labelling by 2013.
"We're well aware that there's an undoubted scare campaign underway on this issue and we think that the way forward on this is to meet head-on the public demands for information and to recommend that the Government institute a mandatory labelling scheme," he said.
PM requested an interview with the Minister for Innovation, Kim Carr, to establish whether the Government has changed its view since the position paper was presented last November.
Senator Carr was not available and PM was referred to the Parliamentary Secretary for Health, Catherine King.
Her spokesman says she is not available either, but the position paper is consistent with the latest advice from the Therapeutic Goods Administration.

Nanotechnology goes full steam ahead

2010-05-04T13:48:00.000-07:00

By Kaitlin Vandervoort

Nanotechnology is the study of controlling matter on an atomic or molecular scale. By being able to deconstruct then reassemble atoms into previously unknown material, nanotechnology has the potential to create numerous new materials and devices such as electronics, energy and medication. Anything from advances in medicine, food and even sports equipment can come from nanotechnology. This may sound promising, but nanotechnology also raises concerns about toxicity and environmental impact of nanomaterials. Many people think that nanotechnology could be a positive effect on society, but research shows differently.

Along with other concerns about nanotechnology, health fears are starting to grow. Molecular biologist, Benedict Trouiller, has been dousing the drinking water of lab mice with nano-titanium dioxide, the most common nanomaterial found in consumer products today, for the past two years. Halfway through the tests, the results had become alarming. When the mice had consumed the nanomaterial, it damaged or destroyed their DNA and chromosomes. The degree of DNA damage could be linked to all the big killers of humans, specifically cancer, heart disease, and neurological disease. According to the Environmental Working Group, nano-titanium dioxide is calculated to be in close to 10,000 over-the-counter products in one form or another. "[It’s] in everything from medicine capsules and nutritional supplements, to food icing and additives, to skin creams, oils and toothpaste," says Professor Robert Schiestl, a generic toxicologist who ran the lab at UCLA’s School of Public Health where Trouiller did her research.

Researchers found that carbon nanotubes, which are widely used in industrial applications, can penetrate the lungs deeper than asbestos and can cause fatal damage like asbestos does, except more rapidly. Many other nanoparticles, specifically ones composed of metal-chemical combinations, are able to cause cancer and birth defects, damage the heart, liver and other organs of lab animals. They may also lead to harmful buildups in many of the body’s systems.

Policy analyst for the Center for Food Safety, Jaydee Hanson, worries that the "danger is greater when nano-titanium dioxide is used in food." Ice cream companies and bread makers are using this nanomaterial to make ice cream "look richer and better textured," and make loaves of bread "shinier and help them keep microbe-free longer"

Researchers have found that due to the size of nanoparticles, they can enter the body through any pathway. The toxicity of a specific nanoparticle depends on its shape and chemical composition. "There is so much uncertainty about the questions of safety. We can’t tell you how safe or unsafe nanomaterials are. There is just too much we just don’t yet know," says Jim Alwood, nanotechnology coordinator of the Environmental Protection Agency’s Office of Pollution Prevention and Toxics.

Even though this research shows that nanomaterials can be harmful, most federal agencies are taking no action to ensure public safety. Unfortunately, consumers have no way of knowing if the products they are purchasing contain nanomaterials because, under current U.S. laws, it is up to the manufacturer’s discretion what they want to put on their labels.

Unfortunately, society would like to see technology that can help people. Nanotechnology manufacterers should have shown the brighter side to everything in the begining but now, we might have to be careful with the products we use.

Nanotechnology finding lands Chennai scholar big bucks job in US

2010-03-09T11:23:00.000-08:00

A Chennai scholar has set an example for students who prefer lucrative managerial jobs to arduous research.R Shivaraman, 24, a researchscholar with SRM University, has landed a Rs1.4-crore-a-year job with an American firm for his work in increasing the capacity of computer hard drives. He holds a joint patent with another Indian for the innovation, that enables a hard drive to store 30 terabyte as against the current 500 gigabyte.
Shivaraman, who works at the Nanotechnology Research Centre of SRM, used to earn Rs12,000 per month before he was signed up by US-based Seagate Technologies as an associate scientist.
He will work on developing ultra high-density storage devices for magnetic recording after he takes up his new assignment in December. He is currently working to complete his PhD here.
His mentor and director of the Nanotechnology Research Centre, C Gopalakrishnan, said Shivaraman had been working on the development of new generation storage devices with far higher storage capacity than available today.
Gopalakrishnan said Shivaraman’s research would help Seagate Technologies use polymer templated technology to increase hard disc capacity.
“I dedicate the honour to SRM University which encouraged me at every stage since my journey in nanotechnology began six years ago. I will come back and associate with SRM,” Shivaraman said. He has sought a two-year assignment with Seagate.
Shivaraman was also invited to the IEEE International Magnetics Summer School in Nanjing University, China, in September 2009. The Chinese sent the invitation after his presentations at the 10th International Magnetics Conference in the US in May 2009. He has presented several papers in Egypt, Australia, US and Spain.

A practical example of solving environmental problems utilizing nanotechnology

2010-02-08T12:11:00.000-08:00

(Nanowerk Spotlight) Carbon nanotubes (CNTs) are 'strange' nanostructures in a sense that they have both high mechanical strength and extreme flexibility. Deforming a carbon nanotube into any shape would not easily break the structure, and it recovers to original morphology in perfect manner. Researchers in China are exploiting this phenomenon by making CNT sponges consisting of a large amount of interconnected nanotubes, thus showing a combination of useful properties such as high porosity, super elasticity, robustness, and little weight (1% of water density).
The nanotube sponges not only show exciting properties as a porous material but they also are very promising to be used practically in a short time. The production method is simple and scalable, the cost is low, and the sponges can find immediate use in many fields related to water purification.
"We hope to give an example to industry that this sponge is a real thing they can prepare at low cost, make versatile products with high performance, and solve environmental problems utilizing nanotechnology," Anyuan Cao, a professor in the Department of Advanced Materials and Nanotechnology at Peking University, tells Nanowerk.
Cao explains that the nanotube sponges are a completely new structure compared with artificial porous materials in several aspects: The sponge is built entirely with nanotubes through a random (yet desired) interconnection. With a high porosity of >99%, the sponge can be compressed to less than 10% of its original volume yet still recover perfectly. Usually, porous materials (e.g. silica aerogels) tend to become brittle at increasing porosity, thus obtaining a material with both high porosity and flexibility has been challenging.
"Plastic foams can be deformed in a similar way to our sponges, but they do not have such high elasticity (full structural recovery) and stability at high temperature" says Cao. "I think that the soft and elastic nanotube sponges are actually similar to some biological cellulose scaffolds."
The motivation of the team – Cao's group and collaborators from Tsinghua University –is to explore potential applications of nanotechnology, especially in energy and environmental areas.
Cao notes that fabricating porous materials with nanostructures such as carbon nanotubes could take advantage of their high surface area and excellent mechanical strength and flexibility. "We have accumulated much experience in synthesizing macroscale products in recent years, and when we made this sponge-like nanotube bricks, we became convinced that they could find use in absorbing solvents, oils, even metal ions."
The scientists synthesized the sponges by a chemical vapor deposition (CVD) process during which the CNTs (multi-walled nanotubes with diameters in the range of 30 to 50nm and lengths of tens to hundreds of micrometers,) self-assembled into a porous, interconnected, three-dimensional framework.
"Our CVD method is similar to that was reported for growing vertical CNT arrays, but we used a different carbon source (dichlorobenzene) to disturb the aligned growth and obtain a randomly interconnected structure," explains Cao. "The growth process of the sponges can be seen as a consecutive stacking and penetration of numerous CNT 'piles' into centimeter thickness, which is substantially different from aligned arrays where most of CNTs grow continuously from the bottom to top surface or thin sheets where CNTs were densified into a two-dimensional network during vacuum filtration."
According to the scientists, the CNT sponges are capable of absorbing a wide range of solvents and oils with excellent selectivity, recyclability, and absorption capacities up to 180 times their own weight, two orders of magnitude higher than activated carbon.
The potential application areas for these sponges is vast. They could be used in large-area oil spill clean-ups (A small densified pellet floating on water surface can quickly remove a spreading oil film with an area up to 800 times that of the sponge), water purification (by targeted absorption of small dusts and unwanted molecules/ions from water), and toxic gas filtration. In addition to environmental applications, the CNT sponges can find use as protective coating, thermal insulator, and high strength-to-weight composite. For example, the sponges can absorb mechanical energy during large-strain deformation, therefore resist foreign force or impact. Their high surface area and porosity are also useful for supporting fine catalyst particles in photo-catalytic devices and fuel cells.
Cao cautions that safety concerns of this sponge material need to be explored before extensive use in certain situations (e.g. in water) can take place. While the sponge can be compressed arbitrarily and repeatedly, its tensile strength is relatively small – it is weak when you pull. This could cause the structure to split in certain conditions, for example, under bending or tensile stress. It is also possible that individual nanotubes detach from the sponge body during use, which could be problematic as chemical interaction of CNTs with human tissue and organs is still unclear.
"Despite of that, there are many ways to strengthen and secure our sponges to ensure the safety of those nano-products" says Cao.
Currently, the team are working on making better samples with larger size. Of particular interest is to tailor the structure and properties of the nanotube sponges to facilitate different applications.
"We can already control pore size, internal surface area, electrical and mechanical properties (related to the structure of individual nanotubes and how they are assembled) during synthesis and post-treatment" says Cao. "We are also involving methods such as chemical functionalization to make CNT sponges more or less attract specific molecules. Because the sponge pore size is relatively large (several to tens of nanometers), small molecules (e.g. gas, ions) are difficult to be absorbed and immobilized inside pristine-form sponges. It is challenging to find suitable chemical routes that can make the sponges selectively remove those molecules from water or environment, after that anchor and store them in a safe manner."

Nanotechnology in the Fight Against Cancer

2010-02-08T11:59:00.000-08:00

Mauro Ferrari, Ph.D., explains how advanced nanotech-based therapeutic agents possess characteristics that can effectively exploit the unique mechanical properties of cancer lesions and treat the various forms of the disease locally.

According to Ferrari, professor and chairman of the Department of Nanomedicine and Biomedical Engineering at The University of Texas Health Science Center, some engineered nano-particles have demonstrated the capability to deliver drugs only to areas affected by disease, in the process protecting healthy cells and reducing debilitating side effects.

An important insight in understanding how to treat cancer, Ferrari says, is that aspects of the disease such as malignancy, metastasis, and angiogenesis (which is the growth of new arteries to feed tumors) are mechanical phenomena pertaining to the motion and transport of blood and cells. Nanotechnology-based therapies currently under experimentation for cancer treatment take advantage of some of these mechanical properties to find new ways to attack tumors.

This constitutes a new field that Ferrari and his medical colleagues refer to as “transport oncophysics.”

Formulations of drugs made from nano-particles have shown the ability to overcome biological barriers -- for example, by leaking through the blood vessels inside a tumor -- to concentrate on localized cancers. Because of this, nanotechnology-based drugs may be used in smaller doses and are less likely to disperse to healthy parts of the body. Ferrari and his team at The University of Texas also have designed nano-particles called Multi-Stage Vectors, which offer great promise in targeting individual cancer cells.

“We are on the brink of a new era in cancer treatment,” asserts Ferrari in the forthcoming article, titled “Infernal Mechanism.”

“The level of specificity that can be achieved through the use of the conceptual model of cancer as a mechanical disease - and through the power of the mechanical engineering design process - will result in greater therapeutic efficacy with reduced side effects,” he concludes.

Mauro Ferrari will speak on Feb. 8 at the First Global Congress on Nano-engineering for Medicine and Biology. The conference, sponsored by ASME, will open on Feb. 7 at the JW Marriott Houston, in Houston, Texas.

Provided by ASME

Composite nanomaterials show promise for solar hydrogen generation

2010-02-08T11:50:00.000-08:00

Using sunlight to split water into hydrogen and oxygen is potentially a clean and sustainable way to generate hydrogen for fuel-cell vehicles. Photovoltaic cells use solar energy to generate electricity, and electricity can be used to split water by electrolysis. But a more direct and efficient approach is provided by photoelectrochemical (PEC) cells, which use solar energy to generate hydrogen inside the cell itself.

The UCSC researchers focused on the semiconductor material used as a light-absorbing anode in the PEC cell. They combined two techniques--called elemental doping and quantum dot sensitization--that have been used to improve the performance of metal oxide semiconductors in solar cells. These techniques use nanotechnology to manipulate the structure of a material on the scale of billionths of a meter.

Previous work in the laboratory of Jin Zhang, professor of chemistry and biochemistry at UCSC, showed that this combination of techniques has a synergistic effect, markedly enhancing the performance of photovoltaic cells (see earlier story). In the new study, Zhang teamed up with Yat Li, assistant professor of chemistry and biochemistry, to test the same strategy in a PEC cell.

"Elemental doping and quantum dot sensitization are two different techniques that work well by themselves. We found that we can combine them to get a synergistic effect," Li said. "We not only extended this idea nicely to a photoelectrochemical cell for hydrogen generation, we also proposed a new model to explain the observed experimental data."

Zhang noted that more theoretical work is needed to fully understand the mechanisms involved. "Understanding the mechanisms will allow us to optimize the effects," he said. "The model we proposed in the first paper was very preliminary, but the new results have helped us refine our model."

The researchers reported their findings in the journal Nano Letters in a paper posted online on January 25. Lead authors of the paper were Jennifer Hensel, a graduate student in Zhang's lab, and Gongming Wang, a graduate student in Li's lab.

The researchers synthesized thin films of titanium dioxide nanoparticles, as well as titanium dioxide nanowire arrays vertically aligned in a thin film on a substrate. The titanium dioxide films were doped with nitrogen, and cadmium selenide nanoparticles were used for quantum dot sensitization. The resulting nanostructured composite materials were then used as photoanodes in a PEC cell to compare their performance in carefully controlled experiments.

The results are an important demonstration of the potential to improve the performance of photoelectrochemical cells, as well as photovoltaic solar cells, using carefully designed materials, Zhang said. "The key is that combining different approaches in a rational manner can significantly boost performance," he said.

Nanotechnology can replace your medical memory

2010-01-27T05:36:00.000-08:00

Forget an apple a day; scientists are working on a pill that would be much more successful in the ongoing battle to find a way to keep the doctor away by giving you medicine without your even knowing about it.

New Scientist reports that scientists at the Massachusetts Institute of Technology have designed nanoparticles to target artery walls around the heart and release small quantities of drugs on a timed basis decided upon by a doctor beforehand. Professor Omid Farokhzad of Harvard Medical School was part of the research team at MIT:

Here we take a big leap forward by developing nanotechnologies that can do the same thing without interventional techniques that commonly involve taking a patient to the cardiac catherisation lab where stents are placed... It's another example of the huge impact that nanotechnology will have on medicine. You can rationally design therapeutics that are targeted and release their drugs in a pre-programmed way and these may go far beyond our current state-of-the-art approaches in safety and efficacy.

It's not exactly a nanoparticle that will fight off any disease or damage in a preventative manner, but it might be the first step. Here's to our healthy nanoparticled future.

Exploring the Molecular World With Nanotechnology

2009-12-16T11:45:00.000-08:00

In a scenario in the last chapter, we saw Joel Gregory manipulating molecules in the virtual reality of a simulated world using video goggles, tactile gloves, and a supercomputer. The early twenty-first century should be able to do even better. Imagine, then, that today you were to take a really long nap, oversleep, and wake up decades later in a nanotechnological world.

In the twenty-first century, even more than in the twentieth, it's easy to make things work without understanding them, but to a newcomer much of the technology seems like magic, which is dissatisfying. After a few days, you want to understand what nanotechnology is, on a gut level. Back in the late twentieth century, most teaching used dry words and simple pictures, but now—for a topic like this—it's easier to explore a simulated world. And so you decide to explore a simulation of the molecular world.

Looking through the brochure, you read many tedious facts about the simulation: how accurate it is in describing sizes, forces, motions, and the like; how similar it is to working tools used by both engineering students and professionals; how you can buy one for your very own home, and so forth. It explains how you can tour the human body, see state-of-the-art nanotechnology in action, climb a bacterium, etc. For starters, you decide to take an introductory tour: simulations of real twentieth-century objects alongside quaint twentieth-century concepts of nanotechnology.

After paying a small fee and memorizing a few key phrases (any variation of "Get me out of here!" will do the most important job), you pull on a powersuit, pocket a Talking Tourguide, step into the simulation chamber, and strap the video goggles over your eyes. Looking through the goggles, you seem to be in a room with a table you know isn't really there and walls that seem too far away to fit in the simulation chamber. But trickery with a treadmill floor makes the walk to the walls seem far enough, and when you walk back and thump the table, it feels solid because the powersuit stops your hand sharply at just the right place. You can even feel the texture of the carvings on the table leg, because the suit's gloves press against your fingertips in the right patterns as you move. The simulation isn't perfect, but it's easy to ignore the defects. On the table is (or seems to be) an old 1990s silicon computer chip. When you pick it up, as the beginners' instructions suggest, it looks like Figure 1A. Then you say, "Shrink me!", and the world seems to expand.

FIGURE 1: POWER OF TEN
Frame (A) shows a hand holding a computer chip. This is shown magnified 100 times in (B). Another factor of 100 magnification (C) shows a living cell placed on the chip to show scale. Yet another factor of 100 magnification (D) shows two nanocomputers beside the cell. The smaller (shown as block) has roughly the same power as the chip seen in the first view; the larger (with only the corner visible) is as powerful as mid-1980s mainframe computer. Another factor of 100 magnification (E) shows an irregular protein from the cell on the lower right, and a cylindrical gear made by molecular manufacturing at top left. Taking a smaller factor of 10 jump, (F) shows two atoms in the protein, with electron clouds represented by stippling. A final factor of 100 magnification (G) reveals the nucleus of the atom as a tiny speck.

Vision and Motion

You feel as though you're falling toward the chip's surface, shrinking rapidly. In a moment, it looks roughly like Figure 1B, with your thumb still there holding it. The world grows blurrier, then everything seems to go wrong as you approach the molecular level. First, your vision blurs to uselessness—there is light, but it becomes a featureless fog. Your skin is tickled by small impacts, then battered by what feel like hard-thrown marbles. Your arms and legs feel as though they are caught in turbulence, pulling to and fro, harder and harder. The ground hits your feet, you stumble and stick to the ground like a fly on flypaper, battered so hard that it almost hurts. You asked for realism, and only the built-in safety limits in the suit keep the simulated thermal motions of air molecules and of your own arms from beating you senseless.

"Stop!" gives you a rest from the suit's yanking and thumping, and "Standard settings!" makes the world around you become more reasonable. The simulation changes, introducing the standard cheats. Your simulated eyes are now smaller than a light wave, making focus impossible, but the goggles snap your vision into sharpness and show the atoms around you as small spheres. (Real nanomachines are as blind as you were a moment ago, and can't cheat.) You are on the surface of the 1990s computer chip, between a cell and two blocky nanocomputers like the ones in Figure 1D. Your simulated body is 50 nanometers tall, about 1/40,000,000 your real size, and the smaller nanocomputer is twice your height. At that size, you can "see" atoms and molecules, as in Figure 1E.

The simulation keeps bombarding you with air molecules, but the standard settings leave out the sensation of being pelted with marbles. A moment ago you were stuck tight to the ground by molecular stickiness, but the standard settings give your muscles the effective strength of steel—at least in simulation—by making everything around you much softer and weaker. The tourguide says that the only unreal features of the simulation have to do with you—not just your ability to see and to ignore thermal shaking and bombardment, but also your sheer existence at a size too small for anything so complex as a human being. It also explains why you can see things move, something about slowing down everything around you by a factor of 10 for every factor of 10 enlargement, and by another factor to allow for your being made stronger and hence faster. And so, with your greater strength and some adjustments to make your arms, legs, and torso less sticky, you can stand, see, feel, and take stock of the situation.

Molecular Texture

The ground underfoot, like everything around you, is pebbly with atom-sized bumps the size of your fingertips. Objects look like bunches of transparent grapes or fused marbles in a variety of pretty but imaginary colors. The simulation displays a view of atoms and molecules much like those used by chemists in the 1980s, but with a sharper 3-D image and a better way to move them and to feel the forces they exert. Actually, the whole simulation setup is nothing but an improved version of systems built in the late 1980s—the computer is faster, but it is calculating the same things. The video goggles are better and the whole-body powersuit is a major change, but even in the 1980s there were 3-D displays for molecules and crude devices that gave a sense of touching them.

The gloves on this suit give the sensation of touching whatever the computer simulates. When you run a fingertip over the side of the smaller nanocomputer, it feels odd, hard to describe. It is as if the surface were magnetic—it pulls on your fingertip if you move close enough. But the result isn't a sharp click of contact, because the surface isn't hard like a magnet, but strangely soft. Touching the surface is like touching a film of fog that grades smoothly into foam rubber, then hard rubber, then steel, all within the thickness of a sheet of corrugated cardboard. Moving sideways, your fingertip feels no texture, no friction, just smooth bumps more slippery than oil, and a tendency to get pulled into hollows. Pulling free of the surface takes a firm tug. The simulation makes your atom-sized fingertips feel the same forces that an atom would. It is strange how slippery the surface is—and it can't have been lubricated, since even a single oil molecule would be a lump the size of your thumb. This slipperiness makes it obvious how nano-scale bearings can work, how the parts of molecular machines can slide smoothly.

But on top of this, there is a tingling feeling in your fingers, like the sensation of touching a working loudspeaker. When you put your ear against the wall of the nanocomputer, you flinch back: for a moment, you heard a sound like the hiss of a twentieth—century television tuned to a channel with no broadcast, with nothing but snow and static—but loud, painfully loud. All the atoms in the surface are vibrating at high frequencies, too fast to see. This is thermal vibration, and it's obvious why it's also called thermal noise.

Gas and Liquid

Individual molecules still move too quickly to see. So, to add one more cheat to the simulation, you issue the command "Whoa!", and everything around seems to slow down by a factor of ten.

On the surface, you now can see thermal vibrations that had been too quick to follow. All around, air molecules become easier to watch. They whiz about as thick as raindrops in a storm, but they are the size of marbles and bounce in all directions. They're also sticky in a magnet-like way, and some are skidding around on the wall of the nanocomputer. When you grab one, it slips away. Most are like two fused spheres, but you spot one that is perfectly round—it is an argon atom, and these are fairly rare. With a firm grip on all sides to keep it from shooting away like a watermelon seed, you pinch it between your steel-strong fingers. It compresses by about 10 percent before the resistance is more than you can overcome. It springs back perfectly and instantly when you relax, then bounces free of your grip. Atoms have an unfamiliar perfection about them, resilient and unchanging, and they surround you in thick swarms.

At the base of the wall is a churning blob that can only be a droplet of water. Scooping up a handful for a closer look yields a swarm of molecules, hundreds, all tumbling and bumbling over one another, but clinging in a coherent mass. As you watch, though, one breaks free of the liquid and flies off into the freer chaos of the surrounding air: the water is evaporating. Some slide up your arm and lodge in the armpit, but eventually skitter away. Getting rid of all the water molecules takes too much scraping, so you command "Clean me!" to dry off.

Too Small and Too Large

Beside you, the smaller nanocomputer is a block twice your height, but it's easy to climb up onto it as the tourguide suggests. Gravity is less important on a small scale: even a fly can defy gravity to walk on a ceiling, and an ant can lift what would be a truck to us. At a simulated size of fifty nanometers, gravity counts for nothing. Materials keep their strength, and are just as hard to bend or break, but the weight of an object becomes negligible. Even without the strength-enhancement that lets you overcome molecular stickiness, you could lift an object with 40 million times your mass—like a person of normal size lifting a box containing a half-dozen fully loaded oil tankers. To simulate this weak gravity, the powersuit cradles your body's weight, making you feel as if you were floating. This is almost like a vacation in an orbital theme park, walking with stickyboots on walls, ceilings, and whatnot, but with no need for anti-nausea medication.

On top of the nanocomputer is a stray protein molecule, like the one in Figure 1E. This looks like a cluster of grapes and is about the same size. It even feels a bit like a bunch of grapes, soft and loose. The parts don't fly free like a gas or tumble and wander like a liquid, but they do quiver like gelatin and sometimes flop or twist. It is solid enough, but the folded structure is not as strong as your steel fingers. In the 1990s, people began to build molecular machinery out of proteins, copying biology. It worked, but it's easy to see why they moved on to better materials.

From a simulated pocket, you pull out a simulated magnifying glass and look at the simulated protein. This shows a pair of bonded atoms on the surface at 10 times magnification, looking like Figure 1F. The atoms are almost transparent, but even a close look doesn't reveal a nucleus inside, because it's too small to see. It would take 1,000 times magnification to be able to see it, even with the head start of being able to see atoms with your naked eye. How could people ever confuse big, plump atoms with tiny specks like nuclei? Remembering how your steel-strong fingers couldn't press more than a fraction of the way toward the nucleus of an argon atom from the air, it's clear why nuclear fusion is so difficult. In fact, the tourguide said that it would take a real-world projectile over a hundred times faster than a high-powered rifle bullet to penetrate into the atomic core and let two nuclei fuse. Try as you might, there just isn't anything you could find in the molecular world that could reach into the middle of an atom to meddle with its nucleus. You can't touch it and you can't see it, so you stop squinting though the magnifying glass. Nuclei just aren't of much interest in nanotechnology.

Puzzle Chains

Taking the advice of the tourguide, you grab two molecular knobs on the protein and pull. It resists for a moment, but then a loop comes free, letting other loops flop around more, and the whole structure seems to melt into a writhing coil. After a bit of pulling and wrestling, the protein's structure becomes obvious: It is a long chain—longer than you are tall, if you could get it straight—and each segment of the chain has one of several kinds of knobs sticking off to the side. With the multicolored, glassy-bead portrayal of atoms, the protein chain resembles a flamboyant necklace. This may be decorative, but how does it all go back together? The chain flops and twists and thrashes, and you pull and push and twist, but the original tight, solid packing is lost. There are more ways to go wrong in folding up the chain than there are in solving Rubik's Cube, and now that the folded structure is gone, it isn't even clear what the result should look like. How did those twentieth-century researchers ever solve the notorious "protein folding problem"? It's a matter of record that they started building protein objects in the late 1980s.

This protein molecule won't go back together, so you try to break it. A firm grip and a powerful yank straightens a section a bit, but the chain holds together and snaps back. Though unfolding it was easy, even muscles with the strength of steel—the strength of Superman—can't break the chain itself. Chemical bonds are amazingly strong, so it's time to cheat again. When you say, "Flimsy world—one second!" while pulling, your hands easily move apart, splitting the chain in two before its strength returns to normal. You've forced a chemical change, but there must be easier ways since chemists do their work without tiny superhands. While you compare the broken ends, they thrash around and bump together. The third time this happens, the chain rejoins, as strong as before. This is like having snap-together parts, but the snaps are far stronger than welded steel. Modern assembler chemistry usually uses other approaches, but seeing this happen makes the idea of molecular assembly more understandable: Put the right pieces together in the right positions, and they snap together to make a bigger structure.

Remembering the "Whoa!" command, you decide to go back to the properly scaled speed for your size and strength. Saying "Standard settings!," you see the thrashing of the protein chain speed up to hard-to-follow blur.

Nanomachines

At your feet is a ribbed, ringed cylindrical object about the size of a soup can—not a messy, loosely folded strand like the protein (before it fell apart), but a solid piece of modern nanotechnology. It's a gear like the one in Figure 1E. Picking it up, you can immediately feel how different it is from a protein. In the gear, everything is held in place by bonds as strong as those that strung together the beads of the protein chain. It can't unfold, and you'd have to cheat again to break its perfect symmetry. Like those in the wall of the nanocomputer, its solidly attached atoms vibrate only slightly. There's another gear nearby, so you fit them together and make the atomic teeth mesh, with bumps on one fitting into hollows on the other. They stick together, and the soft, slick atomic surfaces let them roll smoothly.

Underfoot is the nanocomputer itself, a huge mechanism built in the same rigid style. Climbing down from it, you can see through the transparent layers of the wall to watch the inner works. An electric motor an arm-span wide spins inside, turning a crank that drives a set of oscillating rods, which in turn drive smaller rods. This doesn't look like a computer; it looks more like an engineer's fantasy from the nineteenth century. But then, it is an antique design–the tourguide said that the original proposal was a piece of exploratory engineering dating from the mid-1980s, a mechanical design that was superseded by improved electronic designs before anyone had the tools to build even a prototype. This simulation is based on a version built by a hobbyist many years later.

The mechanical nanocomputer may be crude, but it does work, and it's a lot smaller and more efficient than the electronic computers of the early 1990s. It's even somewhat faster. The rods slide back and forth in a blur of motion, blocking and unblocking each other in changing patterns, weaving patterns of logic. This nanocomputer is a stripped-down model with almost no memory, useless by itself. Looking beyond it, you see the other block—the one on the left in Figure 1D—which contains a machine powerful enough to compete with most computers built in 1990. This computer is a millionth of a meter on a side, but from where you stand, it looks like a blocky building looming over ten stories tall. The tourguide says that it contains over 100 billion atoms and stores as much data as a room full of books. You can see some of the storage system inside: row upon row of racks containing spools of molecular tape somewhat like the protein chain, but with simple bumps representing the 1s and 0s of computer data.

These nanocomputers seem big and crude, but the ground you're now standing on is also a computer—a single chip from 1990, roughly as powerful as the smaller, stripped-down nanocomputer at your side. As you gaze out over the chip, you get a better sense for just how crude things were a few decades ago. At your feet, on the smallest scale, the chip is an irregular mess. Although the wall of the nanocomputer is pebbly with atomic-scale bumps, the bumps are as regular as tile. The chip's surface, though, is a jumble of lumps and mounds. This pattern spreads for dozens of paces in all directions, ending in an irregular cliff marking the edge of a single transistor. Beyond, you can see other ridges and plateaus stretching off to the horizon. These form grand, regular patterns, the circuits of the computer. The horizon—the edge of the chip—is so distant that walking there from the center would (as the tourguide warns) take days. And these vast pieces of landscaping were considered twentieth-century miracles of miniaturization?

Cells and Bodies

Even back then, research in molecular biology had revealed the existence of smaller, more perfect machines such as the protein molecules in cells. A simulated human cell–put here because earlier visitors wanted to see the size comparisons—its on the chip next to the smaller nanocomputer. The tourguide points out that the simulation cheats a bit at this point, making the cell act as though it were in a watery environment instead of air. The cell dwarfs the nanocomputer, sprawling across the chip surface and rearing into the sky like a small mountain. Walking the nature trail around its edge would lead across many transistor-plateaus and take about an hour. A glance is enough to show how different it is from a nanocomputer or a gear: it looks organic, it bulges and curves like a blob of liver, but its surface is shaggy with waving molecular chains.

Walking up to its edge, you can see that the membrane wrapping the cell is fluid (cell walls are for stiff things like plants), and the membrane molecules are in constant motion. On an impulse, you thrust your arm through the membrane and poke around inside. You can feel many proteins bumping and tumbling around in the cell's interior fluid, and a crisscrossing network of protein cables and beams. Somewhere inside are the molecular machines that made all these proteins, but such bits of machinery are embedded in a roiling, organic mass. When you pull your arm out, the membrane flows closed behind. The fluid, dynamic structure of the cell is largely self healing. That's what let scientists perform experimental surgery on cells with the old, crude tools of the twentieth century: They didn't need to stitch up the holes they made when they poked around inside.

Even a single human cell is huge and complex. No real thinking being could be as small as you are in the simulation: A simple computer without any memory is twice your height, and the larger nanocomputer, the size of an apartment complex, is no smarter than one of the submoronic computers of 1990. Not even a bendable finger could be as small as your simulated fingers: in the simulation, your fingers are only one atom wide, leaving no room for the slimmest possible tendon, to say nothing of nerves.

For a last look at the organic world, you gaze out past the horizon and see the image of your own, full-sized thumb holding the chip on which you stand. The bulge of your thumb rises ten times higher than Mount Everest. Above, filling the sky, is a face looming like the Earth seen from orbit, gazing down. It is your own face, with cheeks the size of continents. The eyes are motionless. Thinking of the tourguide's data, you remember: the simulation uses the standard mechanical scaling rules, so being 40 million times smaller has made you 40 million times faster. To let you pull free of surfaces, it increased your strength by more than a factor of 100, which increased your speed by more than a factor of 10. So one second in the ordinary world corresponds to over 400 million here in the simulation. It would take years to see that huge face in the sky complete a single eyeblink.

Enough. At the command "Get me out!", the molecular world vanishes, and your feeling of weight returns as the suit goes slack. You strip off the video goggles—and hugely, slowly, blink.

The Silicon Valley Faire

The tour of the molecular world showed some products of molecular manufacturing, but didn't show how they were made. The technologies you remember from the old days have mostly been replaced—but how did this happen? The Silicon Valley Faire is advertised as "An authentic theme park capturing life, work, and play in the early Breakthrough years." Since "work" must include manufacturing, it seems worth a visit.

A broad dome caps the park — "To fully capture the authentic sights, sounds, and smells of the era," the tourguide politely says. Inside, the clothes and hairstyles, the newspaper headlines, the bumper-to-bumper traffic, all look much as they did before your long nap. A light haze obscures the buildings on the far side of the dome, your eyes burn slightly, and the air smells truly authentic.

The Nanofabricators, Inc., plant offers the main display of early nanotechnology. As you near the building, the tourguide mentions that this is indeed the original manufacturing plant, given landmark status over twenty years ago, then made the centerpiece of the Silicon Valley Faire ten years later, when . . . With a few taps, you reset the pocket tourguide to speak up less often.

Pocket Libraries

As people file into the Nanofabricator plant, there's a moment of hushed quiet, a sense of walking into history. Nanofabricators: home of the SuperChip, the first mass-market product of nanotechnology. It was the huge memory capacity of SuperChips that made possible the first Pocket Library.

This section of the plant now houses a series of displays, including working replicas of early products. Picking up a Pocket Library, you find that it's not only the size of a wallet, but about the same weight. Yet it has enough memory to record every volume in the Library of Congress—something like a million times the capacity of a personal computer from 1990. It opens with a flip, the two-panel screen lights up, and a world of written knowledge is at your fingertips. Impressive.

"Wow, can you believe these things?" says another tourist as he fingers a Pocket Library. "Hardly any video, no 3-D–just words, sound, and flat pictures. And the cost! I wouldn't have bought `em for my kids at that price!"

Your tourguide quietly states the price: about what you remember for a top-of-the-line TV set from 1990. This isn't the cheap manufacturing promised by mature nanotechnology, but it seems like a pretty good price for a library. Hmm . . . how did they work out the copyrights and royalties? There's a lot more to this product than just the technology . . .

Nanofabrication

The next room displays more technology. Here in the workroom where SuperChips were first made, early nanotech manufacturing is spread out on display. The whole setup is surprisingly quiet and ordinary. Back in the 1980s and 1990s, chip plants had carefully controlled clean rooms with gowns and masks on workers and visitors, special workstations, and carefully crafted air flows to keep dust away from products. This room has none of that. It's even a little grubby.

In the middle of a big square table are a half-dozen steel tanks, about the size and shape of old-fashioned milk cans. Each can has a different label identifying its contents: MEMORY BLOCKS, DATA-TRANSMISSION BLOCKS, INTERFACE BLOCKS. These are the parts needed for building up the chip. Clear plastic tubes, carrying clear and tea-colored liquids, emerge from the mouths of the milk cans and drape across the table. The tubes end in fist-sized boxes mounted above shallow dishes sitting in a ring around the cans. As the different liquids drip into each dish, a beater like a kitchen mixer swirls the liquid. In each dish, nanomachines are building SuperChips.

A Nanofab "engineer," dressed in period clothing complete with name badge, is setting up a dish to begin building a new chip. "This," he says, holding up a blank with a pair of tweezers, "is a silicon chip like the ones made with pre-breakthrough technology. Companies here in this valley made chips like these by melting silicon, freezing it into lumps, sawing the lumps into slices, polishing the slices, and then going through a long series of chemical and photographic steps. When they were done, they had a pattern of lines and blobs of different materials on the surface. Even the smallest of these blobs contained billions of atoms, and it took several blobs working together to store a single bit of information. A chip this size, the size of your fingernail, could store only a fraction of a billion bits. Here at Nanofab, we used bare silicon chips as a base for building up nanomemory. The picture on the wall here shows the surface of a blank chip: no transistors, no memory circuits, just fine wires to connect up with the nanomemory we built on top. The nanomemory, even in the early days, stored thousands of billions of bits. And we made them like this, but a thousand at a time–" He places the chip in the dish, presses a button, and the dish begins to fill with liquid.

"A few years latter," he adds, "we got rid of the silicon chips entirely"—he props up a sign saying THIS CHIP BUILD BEGAN AT: 2:15 P.M., ESTIMATED COMPLETION TIME: 1:00 A.M.—" and we sped up the construction process by a factor of a thousand."

The chips in the dishes all look pretty much the same except for color. The new chip looks like dull metal. The only difference you can see in the older chips, further along in the process, is a smooth rectangular patch covered by a film of darker material. An animated flowchart on the wall shows how layer upon layer of nanomemory building blocks are grabbed from solution and laid down on the surface to make that film. The tourguide explains that the energy for this process, like the energy for molecular machines within cells, comes from dissolved chemicals—from oxygen and fuel molecules. The total amount of energy needed here is trivial, because the amount of product is trivial: at the end of the process, the total thickness of nanomemory structure—the memory store for a Pocket Library—amounts to one-tenth the thickness of a sheet of paper, spread over an area smaller than a postage stamp.

Molecular Assembly

The animated flowchart showed nanomemory building blocks as big things containing about a hundred thousand atoms apiece (it takes a moment to remember that this is still submicroscopic). The build process in the dishes stacked these blocks to make the memory film on the SuperChip, but how were the blocks themselves built? The hard part in this molecular-manufacturing business has got to be at the bottom of the whole process, at the stage where molecules are put together to make large, complex parts.

The Silicon Valley Faire offers simulations of this molecular assembly process, and at no extra charge. From the tourguide, you learn that modern assembly processes are complex; that earlier processes—like those used by Nanofabricators, Inc.—used clever-but-obscure engineering tricks; and that the simplest, earliest concepts were never built. Why not begin at the beginning? A short walk takes you to the Museum of Antique Concepts, the first wing of the Museum of Molecular Manufacturing.

A peek inside the first hall shows several people strolling around wearing loosely fitting jumpsuits with attached goggles and gloves, staring at nothing and playing mime with invisible objects. Oh well, why not join the fools' parade? Stepping through the doorway while wearing the suit is entirely different. The goggles show a normal world outside the door and a molecular world inside. Now you, too, can see and feel the exhibit that fills the hall. It's much like the earlier simulated molecular world: it shares the standard settings for size, strength, and speed. Again, atoms seem 40 million times larger, about the size of your fingertips. This simulation is a bit less thorough than the last was—you can feel simulated objects, but only with your gloved hands. Again, everything seems to be made of quivering masses of fused marbles, each an atom.

"Welcome," says the tourguide, "to a 1990 concept for a molecular-manufacturing plant. These exploratory engineering designs were never intended for actual use, yet they demonstrate the basics of molecular manufacturing: making parts, testing them, and assembling them."

Machinery fills the hall. Overall, the sight is reminiscent of an automated factory of the 1980s or 1990s. It seems clear enough what must be going on: Big machines stand beside a conveyor belt loaded with half-finished-looking blocks of some material (this setup looks much like Figure 2); the machines must do some sort of work on the blocks. Judging by the conveyor belt, the blocks eventually move from one arm to the next until they turn a corner and enter the next hall.

FIGURE 2: ASSEMBLER WITH FACTORY ON CHIP

A factory large enough to make over 10 million nanocomputers per day would fit on the edge one of today's integrated circuits. Inset shows an assembler arm together with workpiece on a conveyor belt.

Since nothing is real, the exhibit can't be damaged, so you walk up to a machine and give it a poke. It seems as solid as the wall of the nanocomputer in the previous tour. Suddenly, you notice something odd: no bombarding air molecules and no droplets of water—in fact, no loose molecules anywhere. Every atom seems to be part of a mechanical system, quivering thermal vibration, but otherwise perfectly controlled. Everything here is like the nanocomputer or like the tough little gear; none of it resembles the loosely coiled protein or the roiling mass of the living cell.

The conveyor belt seems motionless. At regular intervals along the belt are blocks of material under construction: workpieces. The nearest block is about a hundred marble-bumps wide, so it must contain something like 100 x 100 x 100 atoms, a full million. This block looks strangely familiar, with its rods, crank, and the rest. It's a nanocomputer—or rather, a block-like part of a nanocomputer still under construction.

Standing alongside the pieces of nanocomputer on the conveyor belt, dominating the hall, is a row of huge mechanisms. Their trunks rise from the floor, as thick as old oaks. Even though they bend over, they rear overhead. "Each machine," your tourguide says, "is the arm of a general-purpose molecular assembler.

One assembler arm is bent over with its tip pressed to a block on the conveyor belt. Walking closer, you see molecular assembly in action. The arm ends in a fist-sized knob with a few protruding marbles, like knuckles. Right now, two quivering marbles—atoms—are pressed into a small hollow in the block. As you watch, the two spheres shift, snapping into place in the block with a quick twitch of motion: a chemical reaction. The assembler arm just stands there, nearly motionless. The fist has lost two knuckles, and the block of nanocomputer is two atoms larger.

The tourguide holds forth: "This general-purpose assembler concept resembles, in essence, the factory robots of the 1980s. It is a computer-controlled mechanical arm that moves molecular tools according to a series of instructions. Each tool is like a single-shot stapler or rivet gun. It has a handle for the assembler to grab and comes loaded with a little bit of matter—a few atoms—which it attaches to the workpiece by a chemical reaction." This is like the rejoining of the protein chain in the earlier tour.

Molecular Precision

The atoms seemed to jump into place easily enough; can they jump out of place just as easily? By now the assembler arm has crept back from the surface, leaving a small gap, so you can reach in and poke at the newly added atoms. Poking and prying do no good; when you push as hard as you can (with your simulated fingers as strong as steel), the atoms don't budge by a visible amount. Strong molecular bonds hold them in place.

Your pocket tourguide—which has been applying the power of a thousand 1990s supercomputers to the task of deciding when to speak up—remarks, "Molecular bonds hold things together. In strong, stable materials atoms are either bonded, or they aren't, with no possibilities in between. Assemblers work by making and breaking bonds, so each step either succeeds perfectly or fails completely. In pre-breakthrough manufacturing, parts were always made and put together with small inaccuracies. These could add up to wreck product quality. At the molecular scale, these problems vanish. Since each step is perfectly precise, little errors can't add up. The process either works, or it doesn't."

But what about those definite, complete failures? Fired by scientific curiosity, you walk to the next assembler, grab the tip, and shake it. Almost nothing happens. When you shove as hard as you can, the tip moves by about one-tenth of an atomic diameter, then springs back. "Thermal vibrations can cause mistakes by causing parts to come together and form bonds in the wrong place," the tourguide remarks. "Thermal vibrations make floppy objects bend further than stiff ones, and so these assembler arms were designed to be thick and stubby to make them very stiff. Error rates can be kept to one in a trillion, and so small products can be perfectly regular and perfectly identical. Large products can be almost perfect, having just a few atoms out of place." This should mean high reliability. Oddly, most of the things you've been seeing outside have looked pretty ordinary—not slick, shiny, and perfect, but rough and homey. They must have been manufactured that way, or made by hand. Slick, shiny things must not impress anyone anymore.

Molecular Robotics

By now, the assembler arm has moved by several atom-widths. Through the translucent sides of the arm you can see that the arm is full of mechanisms: twirling shafts, gears, and large, slowly turning rings that drive the rotation and extension of joints along the trunk. The whole system is a huge, articulated robot arm. The arm is big because the smallest parts are the size of marbles, and the machinery inside that makes it move and bend has many, many parts. Inside, another mechanism is at work: The arm now ends in a hole, and you can see the old, spent molecular tool being retracted through a tube down the middle.

Patience, patience. Within a few minutes, a new tool is on its way back up the tube. Eventually, it reaches the end. Shafts twirl, gears turn, and clamps lock the tool in position. Other shafts twirl, and the arm slowly leans up against the workpiece again at a new site. Finally, with a twitch of motion, more atoms jump across, and the block is again just a little bit bigger. The cycle begins again. This huge arm seems amazingly slow, but the standard simulation settings have shifted speeds by a factor of over 400 million. A few minutes of simulation time correspond to less than a millionth of a second of real time, so this stiff, sluggish arm is completing about a million operations per second.

Peering down at the very base of the assembler arm, you can get a glimpse of yet more assembler-arm machinery underneath the floor: Electric motors spin, and a nanocomputer chugs away, rods pumping furiously. All these rods and gears move quickly, sliding and turning many times for every cycle of the ponderous arm. This seems inefficient; the mechanical vibrations must generate a lot of heat, so the electric motors must draw a lot of power. Having a computer control each arm is a lot more awkward now than it was in pre-breakthrough years. Back then, a robot arm was big and expensive and a computer was a cheap chip; now the computer is bigger than the arm. There must be a better way—but then, this is the Museum of Antique Concepts.

Building-Blocks into Buildings

Where do the blocks go, once the assemblers have finished with them? Following the conveyor belt past a dozen arms, you stroll to the end of the hall, turn the corner, and find yourself on a balcony overlooking a vaster hall beyond. Here, just off the conveyor belt, a block sits in a complex fixture. Its parts are moving, and an enormous arm looms over it like a construction crane. After a moment, the tourguide speaks up and confirms your suspicion: "After manufacturing, each block is tested. Large arms pick up properly made blocks. In this hall, the larger arms assemble almost a thousand blocks of various kinds to make a complete nanocomputer.

The grand hall has its own conveyor belt, bearing a series of partially completed nanocomputers. Arrayed along this grand belt is a row of grand arms, able to swing to and fro, to reach down to lesser conveyor belts, pluck million-atom blocks from testing stations, and plug them into the grand workpieces, the nanocomputers under construction. The belt runs the length of the hall, and at the end, finished nanocomputers turn a corner—to a yet-grander hall beyond?

After gazing at the final-assembly hall for several minutes, you notice that nothing seems to have moved. Mere patience won't do: at the rate the smaller arms moved in the hall behind you, each block must take months to complete, and the grand block-handling arms are taking full advantage of the leisure this provides. Building a computer, start to finish, might take a terribly long time. Perhaps as long as the blink of an eye.

Molecular assemblers build blocks that go to block assemblers. The block assemblers build computers, which go to system assemblers, which build systems, which–at least one path from molecules to large products seems clear enough. If a car were assembled by normal-sized robots from a thousand pieces, each piece having been assembled by smaller robots from a thousand smaller pieces, and so on, down and down, then only ten levels of assembly process would separate cars from molecules. Perhaps, around a few more corners and down a few more ever-larger halls, you would see a post-breakthrough car in the making, with unrecognizable engine parts and comfortable seating being snapped together in a century-long process in a hall so vast that the Pacific Ocean would be a puddle in the corner . . .

Just ten steps in size; eight, starting with blocks as big as the ones made in the hall behind you. The molecular world seems closer, viewed this way.

Molecular Processing

Stepping back into that hall, you wonder how the process begins. In every cycle of their sluggish motion, each molecular assembler gets a fresh tool through a tube from somewhere beneath the floor, and that somewhere is where the story of molecular precision begins. And so you ask, "Where do the tools come from?", and the tourguide replies, "You might want to take the elevator to your left."

Stepping out of the elevator and into the basement, you see a wide hall full of small conveyor belts and pulleys; a large pipe runs down the middle. A plaque on the wall says, "Mechanochemical processing concept, circa 1990." As usual, all the motions seem rather slow, but in this hall everything that seems designed to move is visibly in motion. The general flow seems to be away from the pipe, through several steps, and then up through the ceiling toward the hall of assemblers above.

After walking over to the pipe, you can see that it is nearly transparent. Inside is a seething chaos of small molecules: the wall of the pipe is the boundary between loose molecules and controlled ones, but the loose molecules are well confined. In this simulation, your fingertips are like small molecules. No matter how hard you push, there's no way to drive your finger through the wall of the pipe. Every few paces along the pipe a fitting juts out, a housing with a mechanically driven rotating thing, exposed to the liquid inside the pipe, but also exposed to a belt running over one of the pulleys, embedded in the housing. It's hard to see exactly what is happening.

The tourguide speaks up, saying, "Pockets on the rotor capture single molecules from the liquid in the pipe. Each rotor pocket has a size and shape that fits just one of the several different kinds of molecule in the liquid, so the process is rather selective. Captured molecules are then pushed into the pockets on the belt that's wrapped over the pulley there, then—"

"Enough," you say. Fine, it singles out molecules and sticks them into this maze of machinery. Presumably, the machines can sort the molecules to make sure the right kinds go to the right places.

The belts loop back and forth carrying big, knobby masses of molecules. Many of the pulleys—rollers?—press two belts together inside a housing with auxiliary rollers. While you are looking at one of these, the tourguide says, "Each knob on a belt is a mechanochemical-processing device. When two knobs on different belts are pressed together in the right way, they are designed to transfer molecular fragments from one to another by means of a mechanically forced chemical reaction. In this way, small molecules are broken down, recombined, and finally joined to molecular tools of the sort used in the assemblers in the hall above. In this device here, the rollers create a pressure equal to the pressure found halfway to the center of the Earth, speeding a reaction that –"

"Fine, fine," you say. Chemists in the old days managed to make amazingly complex molecules just by mixing different chemicals together in solution in the right order under the right conditions. Here, molecules can certainly be brought together in the right order, and the conditions are much better controlled. It stands to reason that this carefully designed maze of pulleys and belts can do a better job of molecule processing than a test tube full of disorganized liquid ever could. From a liquid, through a sorter, into a mill, and out as tools: this seems to be the story of molecule processing. All the belts are loops, so the machinery just goes around and around, carrying and transforming molecular parts.

Beyond Antiques

This system of belts seems terribly simple and efficient, compared to the ponderous arms driven by frantic computers in the hall above. Why stop with making simple tools? You must have muttered this, because the tourguide speaks up again and says, "The Special-Assembler Exhibit shows another early molecular-manufacturing concept that uses the principles of this molecule-processing system to build large, complex objects. If a system is building only a single product, there is no need to have computers and flexible arms move parts around. It is far more efficient to build a machine in which everything just moves on belts at a constant speed, adding small parts to larger ones and then bringing the larger ones together as you saw at the end of the hall above."

This does seem like a more sensible way to churn out a lot of identical products, but it sounds like just more of the same. Gears like fused marbles, belts like coarse beadwork, drive shafts, pulleys, machines and more machines. In a few places, marbles snap into new patterns to prepare a tool or make a product. Roll, roll, chug, chug, pop, snap, then roll and chug some more.

As you leave the simulation hall, you ask, "Is there anything important I've missed in this molecular manufacturing tour?"

The tourguide launches into a list: "Yes—the inner workings of assembler arms, with drive shafts, worm gears, and harmonic drives; the use of Diels-Alder reactions, interfacial free-radial chain reactions, and dative-bond formation to join blocks together in the larger-scale stages of assembly; different kinds of mechanochemical processing for preparing reactive molecular tools; the use of staged-cascade methods in providing feed-molecules of the right kinds with near-perfect reliability; the differences between efficient and inefficient steps in molecular processing; the use of redundancy to ensure reliability in large systems despite sporadic damage; modern methods of building large objects from smaller blocks; modern electronic nanocomputers; modern methods for—"

"Enough!" you say, and the tourguide falls silent as you pitch it into a recycling bin. A course in molecular manufacturing isn't what you're looking for right now; the general idea seems clear enough. It's time to take another look at the world on a more normal scale. Houses, roads, buildings, even the landscape looked different out there beyond the Faire dome—less crowded, paved, and plowed than you remember. But why? The history books (well, they're more than just books) say that molecular manufacturing made a big difference; perhaps now the changes will make more sense. Yes, it's time to leave.

As you toss your goggled, gloved jumpsuit into another bin, a striking dark-haired woman is taking a fresh one from a rack. She wears a jacket emblazoned with the name "Desert Rose NanoManufacturing."

"How'd you like it?" she asks with a smile.

"Pretty amazing," you say.

"Yes," she agrees. "I saw this sim back when I was taking my first molecular-manufacturing class. I swore I'd never design anything so clunky! This whole setup really brings back the memories—I can't wait to see if it's as crude as I remember." She steps into the simulation hall and closes the door.

What is Nano Technology

2009-12-16T11:35:00.000-08:00

A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.

In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.

With 15,342 atoms, this parallel-shaft speed reducer gear is one of the largest nanomechanical devices ever modeled in atomic detail. LINK

The Meaning of Nanotechnology

When K. Eric Drexler (right) popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.

Much of the work being done today that carries the name 'nanotechnology' is not nanotechnology in the original meaning of the word. Nanotechnology, in its traditional sense, means building things from the bottom up, with atomic precision. This theoretical capability was envisioned as early as 1959 by the renowned physicist Richard Feynman.

I want to build a billion tiny factories, models of each other, which are manufacturing simultaneously. . . The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. — Richard Feynman, Nobel Prize winner in physics

Based on Feynman's vision of miniature factories using nanomachines to build complex products, advanced nanotechnology (sometimes referred to as molecular manufacturing) will make use of positionally-controlled mechanochemistry guided by molecular machine systems. Formulating a roadmap for development of this kind of nanotechnology is now an objective of a broadly based technology roadmap project led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Nanotech Institute.

Shortly after this envisioned molecular machinery is created, it will result in a manufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications.

Four Generations

Mihail (Mike) Roco of the U.S. National Nanotechnology Initiative has described four generations of nanotechnology development (see chart below). The current era, as Roco depicts it, is that of passive nanostructures, materials designed to perform one task. The second phase, which we are just entering, introduces active nanostructures for multitasking; for example, actuators, drug delivery devices, and sensors. The third generation is expected to begin emerging around 2010 and will feature nanosystems with thousands of interacting components. A few years after that, the first integrated nanosystems, functioning (according to Roco) much like a mammalian cell with hierarchical systems within systems, are expected to be developed.

Some experts may still insist that nanotechnology can refer to measurement or visualization at the scale of 1-100 nanometers, but a consensus seems to be forming around the idea (put forward by the NNI's Mike Roco) that control and restructuring of matter at the nanoscale is a necessary element. CRN's definition is a bit more precise than that, but as work progresses through the four generations of nanotechnology leading up to molecular nanosystems, which will include molecular manufacturing, we think it will become increasingly obvious that "engineering of functional systems at the molecular scale" is what nanotech is really all about.

Conflicting Definitions

Unfortunately, conflicting definitions of nanotechnology and blurry distinctions between significantly different fields have complicated the effort to understand the differences and develop sensible, effective policy.

The risks of today's nanoscale technologies (nanoparticle toxicity, etc.) cannot be treated the same as the risks of longer-term molecular manufacturing (economic disruption, unstable arms race, etc.). It is a mistake to put them together in one basket for policy consideration—each is important to address, but they offer different problems and will require different solutions. As used today, the term nanotechnology usually refers to a broad collection of mostly disconnected fields. Essentially, anything sufficiently small and interesting can be called nanotechnology. Much of it is harmless. For the rest, much of the harm is of familiar and limited quality. But as we will see, molecular manufacturing will bring unfamiliar risks and new classes of problems.

General-Purpose Technology

Nanotechnology is sometimes referred to as a general-purpose technology. That's because in its advanced form it will have significant impact on almost all industries and all areas of society. It will offer better built, longer lasting, cleaner, safer, and smarter products for the home, for communications, for medicine, for transportation, for agriculture, and for industry in general.

Imagine a medical device that travels through the human body to seek out and destroy small clusters of cancerous cells before they can spread. Or a box no larger than a sugar cube that contains the entire contents of the Library of Congress. Or materials much lighter than steel that possess ten times as much strength. — U.S. National Science Foundation

Dual-Use Technology

Like electricity or computers before it, nanotech will offer greatly improved efficiency in almost every facet of life. But as a general-purpose technology, it will be dual-use, meaning it will have many commercial uses and it also will have many military uses—making far more powerful weapons and tools of surveillance. Thus it represents not only wonderful benefits for humanity, but also grave risks.

A key understanding of nanotechnology is that it offers not just better products, but a vastly improved manufacturing process. A computer can make copies of data files—essentially as many copies as you want at little or no cost. It may be only a matter of time until the building of products becomes as cheap as the copying of files. That's the real meaning of nanotechnology, and why it is sometimes seen as "the next industrial revolution."

My own judgment is that the nanotechnology revolution has the potential to change America on a scale equal to, if not greater than, the computer revolution. — U.S. Senator Ron Wyden (D-Ore.)

The power of nanotechnology can be encapsulated in an apparently simple device called a personal nanofactory that may sit on your countertop or desktop. Packed with miniature chemical processors, computing, and robotics, it will produce a wide-range of items quickly, cleanly, and inexpensively, building products directly from blueprints.

◄ Click to enlarge
Artist's Conception of a Personal Nanofactory
Courtesy of John Burch, Lizard Fire Studios (3D Animation, Game Development)

Exponential Proliferation

Nanotechnology not only will allow making many high-quality products at very low cost, but it will allow making new nanofactories at the same low cost and at the same rapid speed. This unique (outside of biology, that is) ability to reproduce its own means of production is why nanotech is said to be an exponential technology. It represents a manufacturing system that will be able to make more manufacturing systems—factories that can build factories—rapidly, cheaply, and cleanly. The means of production will be able to reproduce exponentially, so in just a few weeks a few nanofactories conceivably could become billions. It is a revolutionary, transformative, powerful, and potentially very dangerous—or beneficial—technology.

How soon will all this come about? Conservative estimates usually say 20 to 30 years from now, or even much later than that. However, CRN is concerned that it may occur sooner, quite possibly within the next decade. This is because of the rapid progress being made in enabling technologies, such as optics, nanolithography, mechanochemistry and 3D prototyping. If it does arrive that soon, we may not be adequately prepared, and the consequences could be severe.

We believe it's not too early to begin asking some tough questions and facing the issues:
bullet Who will own the technology?
bullet Will it be heavily restricted, or widely available?
bullet What will it do to the gap between rich and poor?
bullet How can dangerous weapons be controlled, and perilous arms races be prevented?

Many of these questions were first raised over a decade ago, and have not yet been answered. If the questions are not answered with deliberation, answers will evolve independently and will take us by surprise; the surprise is likely to be unpleasant.

It is difficult to say for sure how soon this technology will mature, partly because it's possible (especially in countries that do not have open societies) that clandestine military or industrial development programs have been going on for years without our knowledge.

We cannot say with certainty that full-scale nanotechnology will not be developed with the next ten years, or even five years. It may take longer than that, but prudence—and possibly our survival—demands that we prepare now for the earliest plausible development scenario.