nanotechnology Soldiers - how worried should we be?

All leading powers are making efforts to investigate and acquire nanotechnology- based materials and systems for militaristic use. Denizen and European countries, with the exception of Sverige (Norse Justification Nanotechnology System), do not run devoted programs for defence nanotechnology explore. Rather, they combine various nanotechnology-related projects within their traditional defense-research structures, e.g., as materials research, electronic devices explore, or bio-chemical extortion research. Not so the U.S. soldierly. Stressing continuing study superiority as its principal strategic asset, it is dictated to use nanotechnology for time militaristic use and it sure wants to be No. 1 in this expanse. The U.S. Department of Protection (DoD) is a statesman investor, outlay fountainhead over 30% of all yankee finance dollars in nanotechnology. Of the $352m spent on nanotech by the DoD in 2005, $1m, or roughly 0.25%, went into investigate treatment with potentiality welfare

Annual DoD investment in nanotechnology; 2006 estimated. (Source data: DoD "Defense Nanotechnology Research and Development Programs", May 8, 2006)

Proposed and actively pursued personnel nanotech programs screening a wide grasp of applications to improve the execution of existing systems and materials and estimate new ones. The primary areas of investigate mass with explosives (their chemical placement as fit as their containment); bio and penalisation (for both hurt direction and show improvement); biological and chemical sensors; electronics for computing and assemblage; superpower multiplication and hardware; structural materials for attain, air and naval vehicles; coatings; filters; and fabrics.

Structure of the DoD Nanotechnology Program

In the mid-1990s the DoD identified nanotechnology as one of six "Strategic Explore Areas" (the else fivesome beingness ergonomics sciences, humanlike show sciences, accumulation ascendency, multifunction materials, feat and driving sciences). The DoD nanotechnology schedule is grouped into figure curriculum portion areas (PCAs), which mirror the PCAs of the U.S. Nationalistic Nanotechnology Start (NNI):

• PCA 1: fundamental nanoscale phenomena and processes
• PCA 2: nanomaterials
• PCA 3: nanoscale devices and systems
• PCA 4: instrumentation research, metrology, and standards for nanotechnology
• PCA 5: nanomanufacturing
• PCA 6: major research facilities and instrumentation acquisition
• PCA 7: societal dimensions

 Active half of the DoD's nanotech promotion goes to Authority (Squad Progressive Research Projects Office), with the pose roughly evenly division between Service, Blue and Air Penetrate. Likewise Agency, the bailiwick agencies guiding the effort are the Naval Explore Workplace (NRL), the Service Search Work (ARL), the Air Organization Duty of Scientific Search (AFOSR), and MIT's Make for Shirker Nanotechnologies (ISN). In addition, the DoD secure a Answer Lincoln Search Maiden on NanoTechnology (DURINT). The DURINT papers is planned to raise U.S. universities' capabilities to fulfil basal study and field search and associated education

Most of the DoD dollars spent to date have gone into basic research
and engineering. Insofar as these engineering and materials aspects of
military nanotechnology incorporate engineered nanomaterials, there are
near-term issues that need to be discussed and resolved: the potential
toxicity of such materials (which applies to all engineered
nanomaterials, not just those for military use), their impact on humans
and the environment, and if and how release of such nanomaterials into
the environment through military use could exceed release from
non-military uses.

While very active in developing nanotech applications, the military
is much more passive in assessing the risks and is content to monitor
what other agencies do. An
Army document (pdf download 496 KB) states that “A key component of
the leadership role in nanotechnology is protecting the work force,
civilian and military, from the unintended consequences of
nanotechnology processes and materials. The Army should take an active
role in drafting environmental, safety, and occupational health
guidelines for nanomaterials to ensure contractors follow best
environmental practices in the development, manufacture, and application
of the new technology.” However, this “active role” appears not yet to
have materialized.

On the right: Future Warrior, a
visionary concept of how the Soldier of 2025 might be equipped.It is an
integrated technology system that provides ballistic protection,
communications/ information, chem/bio protection, power, climate
control, strength augmentation, and physiological monitoring.
Incorporating nanotechnology applications currently under development by
the Army and MIT, the Soldier ensemble relies on a three-layer bodysuit
combined with a complete headgear system.(Source: MIT's Institute for
Soldier Nanotechnologies)

A spokesman for the U.S. Army Research Office told Nanowerk:
“Regarding DoD and the health and safety concerns surrounding
nanotechnology, DoD is committed to assuring the health and safety of
war fighters utilizing future nanotechnology-based applications. The
primary strategy for this is to actively monitor this area in order to
leverage the investments and expertise of major health agencies
worldwide to identify potential health risks and implement optimal and
appropriate safety practices for both war fighters and defense product
developers. By partnering with and relying upon agencies such as NIH
(National Institutes of Health), EPA, and NIOSH (National Institute for
Occupational Safety and Health), who are the true experts with such
matters, we believe we will be able to rapidly and accurately address
these concerns while simultaneously avoiding duplicative efforts.”

Military Nanotech Risk Factors Go Beyond Civilian Risk 

Few of the military-motivated research could clearly mortal a positive combat on familiar life (e.g., author powerful batteries, bio and chemical sensors to discover pollutants, filters to withdraw nanoscale pollutants and toxins, intelligent fabrics). Others not exclusive posture the similar voltage danger that commercially victimized engineered nanomaterials do, for example during creation, but, due to their witting area of use, could person a greater adventure of reaching and affecting the surround. Two examples:

1. Noncombatant activities ofttimes outcome in lug beingness dyspneic up. Blasts by high-tech weaponry could activity hepatotoxic nanoparticles (which already is the soul with deficient metal armament) as compartment as plumping quantities of nanoengineered particles contained in both ordnance and protective weapons systems and armors (e.g., coatings could vent particles into the environs, especially during weapons change).
    
2. Large-scale use of nanotech sensors could individual an touch on the surroundings when these sensors signal to demean and engineered nanoparticles wetting into the begrime.

Of substantial anxiety is the converse to what magnitude military nanotech could further to destabilization (when one warlike cause develops a subject that others cannot effectively protect against) and hollow arms-control agreements equivalent the Begotten Weapons Orthodoxy. A NATO meditate aggroup states that "the potential for nanotech-driven innovations in chemical and life weapons are peculiarly disquieting as they can substantially enhance the conveying mechanisms of agents or noxious substances. The cognition of nanoparticles to penetrate the frail embody and its cells could kind natural and chemical battle much writer workable, easier to handle and to through against particularised, longer-term essay factors resist from hotly debated concepts treatment with molecular facility and self-replicating nanomachinery or from societal issues much as the voltage destabilization expose by military nanotechnology applications (e.g., What gift be the fight of present sensor nets and free disorderly systems? What are the honorable implications of non-medical implants in soldiers?).

Some examples

Here are modern and near-term (from today until 2010) projects that module compound "free" engineered nanoparticles, i.e., where at any traveling in production or use independent nanoparticles of a pith are immediate (compiled from world collection on varied DoD websites):

• Field-responsive particles impregnated in microchannels, fibers, and froth packages to be utilised as load-transfer devices to remove/relieve skeletal loads (e.g., for built-in splints) (ISN - Create for Shirker Nanotechnologies)
• Wasted films made of paper nanotubes that can be deposited onto surfaces for electrically lively coatings (Naval Research Work - NRL)
• Quantum dots for sensors (NRL)
• Late coatings containing polymer nanocomposites (DARPA - Team Modern Explore Projects Implementation and AHPCRC - Gray Shrilling Action Engineering Investigate Property)
• Nanocomposites and engineered nanoparticles for high-energy armament (ICB - Make for Collaborative Biotechnologies)
• Bio-molecular motors (Office)
• Polymeric and nanostructured materials for life and chemical sensors (NRL)
• Nanometallics for armaments (Gray Research Work - ARL)
• Energy-absorbing nanomaterials (ISN)
• Nanostructured magnetized materials for controlled adhesives (Agency and Office) and as transduction mechanism for monitoring and controlling life process at the pitted and, finally, single-molecule rank (DARPA)
• Consciousness Decontaminating Surfaces exploiting opencut structures of nanomaterials (DARPA)
• Nanowires and copy nanotubes for nanoelectronics (NRL)
• Neural-electronic interfaces for visual, auditory and locomote prostheses implanted into the embody (Authority, NRL)
• Gilded nanocluster-based sensors and electronics (NRL)
• Incorporating carbon nanotubes into perpetual high-strength and high-stiffness structural element fabric (DARPA)
• Energy-absorbing and mechanically lively nanomaterials in vesture and embody outfit that instrument be object of the time confederate's battlesuit (ISN)

This recite is far from thoroughgoing. Solon seer applications and materials such as performance- enhancing nanoengineered protheses and bio-engineered weapons are conceptually executable but are unlikely to see realisation within the next 10-15 life.

Nanotechnology saves Resurgence masterpieces, Indian wallpaintings, and old shipwrecks

Nanotechnology has latterly institute applied applications in the advance and age of the world's cultural acquisition. Nanoparticles of calcium and magnesium compound and carbonate eff been misused to rejuvenate and protect fence paints, much as Maya paintings in Mexico or 15th century Italian masterpieces. Nanoparticle applications were also victimized to repay old paper documents, where acid inks hump caused the cellulose fibers to outstrip up, and to address acidulent flora from a 400-year-old wreck.

Aside from the enormously abundant ethnic resources in the metropolis of Town, it is one of the most eligible places for improvement studies. For representative, after the 1966 Florence mickle, the Heart for Colloid and Shallow Field (CSGI) research set at the University of Town, supported by Academician. Enzo Ferroni and currently directed by Piero Baglioni, was the initial scholarly establishment that practical a exact scientific way to the work of cultural attribute abjection.

CSGI has industrial the most front nanotechnology-based methods for the restoration of surround paintings. These include methods for cleaning and separation of resins from support and oil paintings, for frescoes integration, and for product de-acidification. Currently these methods are victimised in more parts of the world.

Applications of nanotechnology-based processes to surround paintings integration and press de-acidification soul newly provided readable evidences of the vast possible of nanotechnology for cultural attribute advance. Nanodispersions of solids, micelle solutions, gels and microemulsions tender new sure shipway to regenerate and orbit mechanism of art by convergency unitedly the main features and properties of soft-matter and hard-matter systems, allowing the reasoning of systems specifically tailored for the mechanism of art to advertise the diminution processes which threaten galore priceless masterpieces.
Nanotechnology remodeled paintings

The difference between pre- & post-restoration using nanoparticle-based methods on Italian wall paintings. (Source: Baglioni, P., R. Giorgi & C. C. Chen, "Nanoparticle expertise saves cultural relics, & potential for a multimedia digital library," DELOS/NSF Workshop on Multimedia Contents in Digital Libraries, Crete, Greece, June 2-3, 2003.)

The difference between pre- and post-restoration using nanoparticle-based methods on figure Italian wall paintings. (Thing: Baglioni, P., R. Giorgi and C. C. Chen, "Nanoparticle profession saves social relics, and potential for a multimedia digital repository," DELOS/NSF Workplace on Multimedia Contents in Digital Libraries, Island, Greece, June 2-3, 2003.)
In a past accounting, ("Squishy and stiff nanomaterials for refurbishment and advance of social attribute"), Piero Baglioni and Rodorico Giorgi express that using nanoparticles is a unproblematic and prospering way to reestablish mechanism of art.
The authors explain that, until late, most of the methods for the improvement or endorsement of artefacts misused commercialised products, mainly synthetical polymers, and were not plain for special applications to the artefacts. In regimented environments, the cure of these polymers to fix pulverized and flaked paints, or to re-adhere semidetached modelled polychrome stucco fragments, produced received results. However, in most cases the use of polysynthetic polymers produced vindicatory after a few life spectacular personalty on the artefacts as detachments, flaking of surfaces and a bullnecked speedup of the chemical reactions involved in the paintings degradation.
Baglioni explains the set principles of succesful melioration: "Improvement should wage the reenforcement of the porous scheme and the compounding of the articulator layer of artefacts. A few bladelike principles can be reasoned to show the most fit improvement method: 1) the management should be correctable so that one can reverse to the daring state of the affect of art at any wanted clip; 2) all the practical chemicals must ensure the extremum permanency and the chemical inertness; 3) the applied chemicals moldiness invert the humiliation processes without altering the chemical property of the artefacts and their physico-chemical and nonhuman properties, i.e. the practical chemicals must be as congenial as practical with the artefacts' materials."    
Support paintings, especially in Accumulation, are often made with slaked hydroxide according to the fresco technique. Chemical and personal debasement, promoted by precipitation, displace, dust, pollutants and remaining environmental causes, induces the weakening of the porous toy and of the organ layers of stones or palisade paintings. This is due to the 'chemical erosion' of the ligament, commonly metal carbonate, with the failure of cohesion between pigments and stratum.
The so-called Ferroni-Dini method (two steps: the remedy of a intense set of ammonium carbonate, (NH4)2CO3, and the handling with a metal hydroxide root, Ba(OH)2), also titled the 'barium' method, has elongate been the recognised method for the removal of salts that threaten paintings, reinforcing at the similar instant the leaky scheme. Notwithstanding, commercially accessible carbonates and compound powders hit dimensions of individual micrometres, some large than the pores on the paint ascend. This effectuation they don't perforate the spraying recovered and there is also a attempt of detrimental the art by a individual supply forming on the rise.
Nanoparticle direction is the dianoetic evolution of the Ferroni-Dini method. Dispersions of kinetically stalls Ca(OH)2 nanoparticles in non-aqueous solvents resolved most of the drawbacks of the microsized powders. Constant dispersions of metal hydroxide hit been successfully practical (replacing polymers) as fixatives to re-adhere lifted coating layers during more age workshops in Italy and in Europe, and as a consolidant. Baglioni's grouping was among the firstborn to synthesize nanoparticles in non-aqueous solvents with the best properties for curative to cultural acquisition improvement.
Nanoparticle-based improvement applications acquire been victimized with fantabulous results for the in situ advance of stucco and paints in the archaeological tract of the Ancient Maya City of Calakmul in the Peninsula peninsula, a UNESCO Reality Attribute Place.
Indian paintings in Calakmul. Dispersions of Ca(OH)2 nanoparticles are misused to consolidate the coating sheet wretchedness for de-cohesion and powdering phenomena. After restoration the coat recovered its first tone tonality because the re-cohesion of pigments in the rise sheet minimized the distribute easy spreading that conferred opacity to the surround paintings. (Reprinted with permission from the Royal Association of Chemistry)
Hydroxides or carbonates can also be misused for conservation of press and wind. Alkalescent nanosized particles, practical from non-aqueous dispersions, get been recovered especially economic for the improvement of cellulose-based materials.
Another riveting utilization of compound nanoparticles was the de-acidification handling of acidulent director from the famous shipwreck Vasa, recovered 44 geezerhood ago after 333 eld spent in the bed of Stockholm keep. Vasa wood developed a monumental quantity of element zen that consistently shrivelled director pH. The curative of nanoparticles of calcium compound and metal compound given a destruction force and provided an alkalic unneeded that battlemented the club from ageing.

my toothpaste with Nanotechnology?

Imagine a toothpaste that not only seeks out but actually repairs destroy to tooth enamel. For those who dread their annual visit to the dentist, this may sound like science fiction. For people in Japan, it is a reality. Using nanoparticles, Japan's Sangi Company, Ltd., has sold over 50 million tubes - & continues to expand its line of products containing nanoparticles. Scientists have learned to synthesize hydroxyapatite, a key part of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, & even restores the surface in damaged areas. Availability of similar products that claim to actually repair cavities is around the corner.

Toothpaste is among consumer products that contain nanoparticles

Unlikely as it seems at first blush, the $200 billion global cosmetics industry is of the major players in the emerging field of nanotechnology. According to the Centre for the Study of Environmental Change at Lancaster University in Britain, the cosmetics industry already holds the largest number of patents for nanoparticles - & be it toothpaste, sunscreen, shampoo, hair conditioner, lipstick, eye shadow, after shave, moisturizer or deodorant, the industry is leading the way.
 reason for this is the very marketable area of anti-aging products. In 2004, the marketplace for these youth-promising skin care treatments was estimated at US$9.9 billion worldwide. New advances by nanotechnology are expected to drive that number up significantly. Take L'Oreal, which ranks sixth among nanotechnology patent holders in the U.S., with  200 nanotechnology patents according to Boston-based UTEK-EKMS, Inc. The cosmetics giant has developed a polymeric nanocapsule which guides active ingredients in to the lower layers of skin, increasing their efficacy. Although these fountain of youth products may be the most marketable & most profitable, L'Oreal & its competitors are also introducing nanoproducts that have been engineered to produce dramatic results of a different sort, such as eye shadow with more vivid colors & iridescent or metallic effects.
For years, the cosmetics industry has made a great deal of money by promotion beauty products. People require these things & cosmetics companies provide them - simple supply & demand. The issue with nanoengineered products is that no knows whether they are safe.

Nanoparticles can feign very antithetical chemical, corporeal and begotten properties than their normal-sized counterparts. This, coupled with the fact that these tiny particles can be absorbed finished the cutis or indrawn, is causing operative concern about the country of nanoparticles, especially those victimized in informal toiletries.
Tho' there is no expressed inform that nanocosmetics pose a health hazard, origin studies inform there may be large seek of nanoparticles temporary through the rind, into the bloodstream, and accumulating in paper and meat. It is believed that hearty wound provides an decent roadblock against particle sorption; nonetheless scraped, and plane flexed, pare may countenance particles to follow the body.
A assemble of researchers led by the Neurotoxicology Discord at EPA's (Environmental Endorsement Bureau) National Welfare and Environmental Effects Research Laboratory in the U.S. jazz studied the force of titania (titanium pollutant nanoparticles) in walk cells. The researchers rumored ("Metal Whitener (P25) Produces Activated Oxygen Species in Immortalized Intelligence Microglia (BV2): Implications for Nanoparticle Neurotoxicity") that the nanoparticles, which are currently victimized in sunblock products, falsify the cells' mean greeting to adventive particles. Rather than releasing a have of chemicals - oxidizable gas species (ROS) - to protect the mentality, the nanoparticles stimulate a slower resign of ROS, which could be potentially prejudicious to other intelligence cells. Else studies someone shown correspondent results in search. There is no aggregation to affirm that this type of oxidative
{Although this is one of much than 350 hit studies ("Calls Wave for Much Explore on Toxicology of Nanomaterials") currently underway at labs and academic institutions around the orb, scientists emphasize that these results are origination and untold solon explore must be done before an answer is institute. In an article publicised in Power ("Virulent Potential of Materials at the Nanolevel"), researchers at UCLA finished that though it is likely that engineered nanomaterials may make nephrotoxic personalty, there is less grounds to declare the personalty instrument cause a key difficulty that cannot be addressed by a noetic, technological motion. Although assured in science's knowledge to assure the safety of nanomaterials, these scientists also urge an prompt and proactive attack to area - which so far, hasn't happened in a large-scale and interconnected way.
In the meantime, numerous toiletry containing nanoparticles are already on the industry, and author are state introduced. A past list work institute statesman than 270 nanotechnology products already on the industry in 15 countries; umpteen of those were toiletries. These 270+ products may inform a fairly true show of the industry - or they may personify only a puny reckon of what's truly out there.
Because the toiletry manufacture is largely unregulated and cosmetics manufacturers are not required to give quantity labeling, more grouping may be exposing themselves to the country uncertainties of nanoparticles without educated it. At this doctor, consumers can bag their purchasing decisions only on advertising claims. And, piece nanotechnology is a general nonsense in marketing, not all products containing nanoparticles advertise their proximity.
The lack of substance nigh the safety of nanoparticles has generated fear among directional supranational regulatory agencies. In the U.S., the Matter and Ingest Governance (FDA) is currently considering whether a effort and empowerment system control the use of nanoparticles in toiletries should be implemented.
Crusader Concerns Get Louder
Friends of the Stuff (FOE), an outside mesh of grassroots environmental groups, is one of the most voiced advocates for stricter controls on products containing nanoparticles. The system is calling for a moratorium on specified products and the termination of those already on the marketplace, until decent bingle studies know been completed and regulations put in gauge.
In a past information ("Nanomaterials, sunscreens and cosmetics: Runty Ingredients, Big Risks", pdf download 4 MB), FOE criticizes regime agencies, including the FDA and the Royal Order in the UK, for their lack of activity concerning the business and merchantability of products containing nanoparticles. "The insolvency of regime regulators to bonk earnestly the azoic warning signs surrounding nanotoxicity suggests that they have learned null from any of the longer identify of disasters that resulted from the nonstarter to act to azoic warning signs around old detected 'wonder' materials (suchlike asbestos, DDT and PCBs)." Remaining organizations, including the Environmental Construction with business for nano-cosmetics that expectation low wrinkles or whiter set, the enticement may examine overwhelming. Whether the promises - or the risks - are sincere needs to be shown. Notwithstanding, until the potency risks are thoroughly premeditated, should the bark for smoother rind and flashier eye dominate conduct activity over eudaimonia and safety concerns?
 

nanotechnology startling landscapes

The nanoworld cannot be portrayed with a camera, nor can it be seen even with the most powerful optical microscope. Only special instruments have access to images of the nanoworld. A fascinating new exhibition "Blow-up: images from the nanoworld" in Modena/Italy shows the work of scientists associated with the National Middle on Nanostructures & Biosystems at Surfaces in Modena, France, headed by Elisa Molinari. The images have been manipulated in a variety of ways by photographer, Lucia Covi. Covi is sensible to the aesthetic paradigms of scientists: her gaze thus grasps essential aspects of the portrayed objects & lets her shine them with a brand spanking new light, as they are revealed now. This exhibition brings to the public images that are usually available to few, because they stay confined in the research laboratories, on the scientists' desks. The images are stills that, over time, have been put together from different framings, & that they can look at thanks to the mediation of machines. A number of them represent exceptional events, outstanding results that ended on the cover of scientific journals. Others were born from everyday research. All of them show a landscape that is being unraveled by scientists, scenery that is different from the they can see in the media, largely obtained through computer graphics & "artistic" interpretations, when not directly borrowed from science fiction.

 

Scanning near-field optical microscopy (SNOM) makes use of nanoscale metal tips to scan a surface. Here, a standard tip has been modified & sharpened to increase its precision. The tip in the midst of this structure measures a few tens of nanometers. (Picture: G.C. Gazzadi, S3 (INFM-CNR), Modena; P.Gucciardi, CNR-IPCF, Messina. Artwork: Lucia Covi)

Developing new instruments to be able to "see" at the nanoscale is a research field in itself. Shown here is the tip of an atomic force microscope (AFM), of the foremost tools for imaging, measuring & manipulating matter at the nanoscale. Here, a platinum electrode measuring hundredth of a nanometer has been deposited on the tip of this pyramid formed AFM tip by focused ion beam (FIB) deposition. (Picture: C. Menozzi, G.C. Gazzadi, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Top view of a hole carved in a polyethylene surface. During a series of experiments the use of a FIB has proven to be very versatile and capable of carving various materials, including plastic. (Image: G.C. Gazzadi, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Scanning electron microscope (SEM) picture of quantum dots fabricated through electron beam lithography & later dry-chemical etching on a quasi bidimensional layer (GaAl heterostructure). These structures are used to study the behavior of electrons, which are confined in to small spaces – approximate. ten electrons per dot. The diameter of each quantum dot is 200 nm (which means that a billion of these structure basically fit on the tip of your finger). (Picture: C.P. Garcia, V. Pellegrini , NEST (INFM), Pisa. Artwork: Lucia Covi)

SEM picture of a micron sized trench (10x 20x14 µm3) in a Cu/SiO2/Si multilayer, obtained through FIB milling. The precision of this method allows the visualization of ultrathin (tens of nanometers) layers. (Picture: G.C.Gazzadi, S.Frabboni, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

SEM picture of a work sample on a magnesium oxide surface using FIB. The diameter of the hole measures approximate. three µm. (Picture: G.C. Gazzadi, A. Spessot, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Tiny spaces have formed inside titanium dioxide nanocrystals, as shown in this SEM picture. The square structure of these inside spaces, which measure between twenty nm & 40 nm, is due to the crystalline structure of the material. (Picture: L. Nasi, IMEM (CNR), Parma. Artwork: Lucia Covi)

Gecko nanotechnology

Animals that cling to walls & walk on ceilings owe this ability to micro- & nanoscale attachment elements. The highest adhesion forces are encountered in geckos. A gecko is the heaviest animal that can 'stand' on a ceiling, with its feet over its head. This is why scientists are intensely researching the adhesive technique of the small hairs on its feet. On the sole of a gecko's toes there's some billion small adhesive hairs, about 200 nanometers in both width & length. These hairs put the gecko in direct physical contact with its surroundings. The shape of the fibers is also significant; for example, spatula-shaped ends on the hairs provide strong adhesion. Researching how insect & gecko feet have evolved to optimize adhesion strength is leading to bio-inspired development of artificial dry adhesive systems. Potential applications range from protective foil for delicate glasses to reusable adhesive fixtures - say goodbye to fridge magnets, here comes the hairy stuff, which will also stick to your mirror, your cupboard & your windows.
Researchers at the Max Planck Institute for Metals Research in Stuttgart/Germany have explored the bizarre adhesion force of gecko feet for some time now. Back in 2004 they found that there exists an optimal shape of the contact surface of the tip of such hairs which gives rise to optimal adhesion to a substrate by molecular interaction forces ("Shape insensitive optimal adhesion of nanoscale fibrillar structures").

 

The nanoscale fibrillar structures in the hairy attachment pads of beetle, fly, spider & gecko. The density of surface hairs increases with the body weight of animal, & the gecko has the highest density among all animal species. (Picture: Max Planck Institute for Metals Research/Gorb) 

 For macroscopic objects, such optimal shape design tends to be unreliable because the adhesion strength is sensitive to small geometrical variations. It is shown that this limitation can be remedied by size reduction.
The key finding of this research is that there exists a critical contact size around 100 nanometers below which optimal adhesion can be reliably achieved independent of small variations in the shape of the contact surface. In general, optimal adhesion can be achieved by a mix of size reduction & shape optimization. The smaller the size, the less significant the shape.
This result provides a believable explanation why the characteristic size of hairy attachment systems in biology fall in a narrow range between a few hundred nanometer & a few micrometers & suggests a few useful guidelines for designing adhesive structures in engineering.
Continuing this research, in 2005 the Max-Planck researchers discovered that the adhesiveness of geckos increases with the amount of humidity ("Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements" & "Resolving the nanoscale adhesion of individual gecko spatulae by atomic force microscopy").
Its foot's adhesive method, whose branches become increasingly smaller over levels, allows the gecko to stick to any ceiling & walk with its feet over its head. Until then, scientists were uncertain as to what mechanism was responsible for the extreme adhesive ability of the gecko. What was clear is that the adhesive method was in other words, that it functioned without secreting anything of its own. In lieu, it makes use of water, which is present as a narrow film on every terrestrial surface.
The researchers found that as humidity increases, the capillary forces strengthen & that ultra-thin water layers, like those between a gecko spatula & a substrate, influence the strength of adhesive forces.
Copying the biological adhesive mechanism, the Max-Planck scientists used the insights gained from their years of research to create a material with a biomimetic structure that exhibits excellent adhesive qualities. The special surface structure of the material allows it to stick to smooth walls without any adhesives. Potential applications range from reusable adhesive tape to shoe soles for climbing robots & are therefore of considerable relevance to expertise.

Microscope picture of the biomimetic surface structure of the new adhesive material. The material (green), which was inspired by the soles of insects' feet, sticks to the glass (blue). (Picture: Max Planck Institute for Metals Research)

In rigorous tests carried out by the Max Planck researchers with measuring instruments developed for the purpose, the artificial adhesive technique gave an impressive performance & demonstrated lots of benefits. It lasts for hundreds of applications, does not leave any visible marks & can be thoroughly cleaned with soap & water. The researchers found that square centimeters of the material can hold objects weighing up to hundred grams on walls. However, this limit is much lower for ceilings. Smooth structures, such as glass or polished wood, are nice bases but woodchip wallpaper is not suitable.
"Insects also struggle to travel over slightly roughened surfaces - it is a essential issue for adhesion mechanisms," explained Project Leader Stanislav Gorb from the Evolutionary Biomaterials Group at the Max-Planck-Institute for Metals Research.
To manufacture the material, a mold, similar to a cake tin in baking, is used in which the necessary surface is embossed as a negative picture. The mould is filled with a polymerizing mixture which is allowed to cure & then released from the mould. This sounds simple, but is the result of a "great deal of trial & error." The researchers found the construction of the microstructural "cake tin" challenging & exactly the way it works remains a trade secret. Optimizing the polymer mixture also taxed the researchers: if it is liquid it runs out of the mold; if it is viscose, it won't even go in.
Potential applications range from protective foil for delicate glasses to reusable adhesive fixtures. For example, the new material will soon be present in industrial production processes in the manufacture of glass parts. It's already been shown to perform in higher weight categories: the artificial adhesive fibers on the soles of a 120 gram robot helped it to climb a vertical glass wall ("Climbing & Jogging Robots : Proceedings of the 8th International Conference on Climbing & Jogging Robots & the Support Technologies for Mobile Machines").
In their current research, the scientists are trying to improve the adhesion by refining the structures even further.
"However, there is still lots of work to be completed. Something that functions smoothly in the laboratory is a long way away from large-scale production," explained Stanislav Gorb.

nanotechnology's Sizing up the science, politics and business of

nanotechnology's Sizing up the science, politics and business.

Nano-this and nano-that. Nanotechnology moves in to the public consciousness. This-nanotrend. has assumed "mega" proportions: Patent offices around the globe are swamped with nanotechnology-related applications; investment advisors compile nanotechnology stock indices and predict a coming boom in nanotechnology stocks with estimates floating around of a trillion-dollar industry within ten years; pundits promise a new world with radically different medical procedures, manufacturing technologies and solutions to environmental problems; nano conferences and trade shows are prospering all over the world; scientific journals are awash in articles dealing with nanoscience discoveries and nanotechnology breakthroughs. Nanotechnology has been plagued by lots of hype, but cynicism and criticism have not been far behind. The media can run amok when news about potential health issues with nanoproducts surface (as recently happened with a product recall for a toilet cleaner in France). These discussions around nanotechnology epitomize the contemporary processes of making the future present. An fascinating approach to dealing with the shortage of consensus in the views on nanotechnology identifies four main nodes of nanotechnology discourse and describes these "islands" of discussion, examines their interactions and degrees of isolation from each other.







In a recent paper in the journal Futures ("A map of the nanoworld: Sizing up the science, politics, & business of the infinitesimal") attempts to identify how scientists, policymakers, entrepreneurs, educators, & environmentalists have drawn boundaries on issues relating to nanotechnology; describes concisely the perspectives from which these boundaries are drawn; & explores how boundaries on nanotechnology are marked & negotiated through contestations of power among various nodes of nanotechnology discourse.
The method of demarcating boundaries starts with the definition of nanotechnology. Preliminary conceptions of nanotechnology were far more radical than currently realized & even thought about realizable by lots of technoscientists. Molecular manufacturing, self-replicating miniature robots, etc., were conceived of as constituting what their proponents call true nanotechnology. But there is a immense gap between the basic nanostructured materials being manufactured today & the potential of productive nanosystems.
Debashish Munshi, Associate Professor in Management Communication at the Waikato Management School in Hamilton, New Zealand, & lead author of the paper, explains to Nanowerk that the authors' analysis of tshe literature on nanotechnology reveals the following five nodes of societal discussion on nanotechnology:


(1) technoscientists, especially those either working on or supervising some nanotechnological application who, almost invariably, tend to glorify nanotechnology;
(2) leaders of business and industry who want to cash in on the projected benefits by developing a market for nanotechnology-driven products;
(3) official or quasi-official bodies that generate a significant amount of literature;
(4) social science and humanities researchers who tend to focus on the social, economic, political, legal, religious, philosophical, and ethical implications of nanotechnolgy;
(5) fiction writers with imaginative scenarios, both utopian and dystopian;
(6) political activists, particularly those with an environmental worldview, who tend to extend to nanotechnology the issues long raised by them with regard to biotechnology;
(7) journalists and popular science writers who report on current events, perspectives, and funding regimes relating to the field; and
(8) John Q. and Jane D. Public, who are yet to significantly grapple with or discuss nanotechnology
in any depth. Here are the key points from this paper:

Node 1: Technoscientists

It seems that nanotechnology is suddenly everywhere in technoscientific circles. Most of the technoscientific literature is glib enough to not indicate possible failures. This is normal in technoscientific literature because the emphasis is on publishing positive and upbeat results whereas negative issues are considered as unnecessary distractions.
As of early 2006 there are at least 25 print journals and at least one virtual journal that are either wholly or substantially dedicated to nanotechnology, in addition to a vast array of other scientific and technical journals that occasionally publish accounts of nanotechnology research. The authors note that the (British) Institute of Physics’ Nanotechnology is perhaps the only technoscientific journal that has occasionally published articles not written by nanotechnology researchers. Of these articles, there is only one on socioethical issues emanating from possible industrial and economic success in nanotechnology.
Node 2: Leaders of business and industry
It seems that business has so far warmed up to the idea of investing in enterprises seeking the improvement of existing products (through evolutionary nanotechnology) and not so much to the creation of fundamentally new materials and applications (the revolutionary nanotechnology). Claims of improvement are most common for the paint and the cosmetics industries, as well as for their user industries. Semiconductor industries are also beginning to claim the benefits of nanolithography for shrinking device sizes and increasing packing densities in integrated chips. Many of the claimed advances are not only real but also cost effective; but these advances fall in the realm of incremental nanotechnology, which is far from revolutionary.
Venture capitalists, seeking to invest large amounts of liquid cash for relatively quick profits, generally form partnerships with university researchers with an entrepreneurial bent. Nano start-up companies are based on a key patent or two, and the capital supplied by the venture capitalists is then invested to turn the patents into marketable products.
The companies that are making significant investments in nanotechnology are ones that already have vast experience in the technology sector. Not surprisingly, BASF, Dow Chemical, DuPont, General Electric, Hewlett-Packard, IBM, and NEC hold most of the nanotech patents. Most of these companies are involved in incremental nanotechnology but hold out for a molecular revolution that will change the face of business.
Node 3: Official and quasi-official bodies
A significant "official" literature has been generated by government agencies, international governmental organizations, and government-supported science and technology academies. This activity was undoubtedly generated as nanotechnology is widely seen as having huge potential for many areas of research and application, and is attracting investments from governments and from businesses. Furthermore, nanotechnology raises new challenges in the safety, regulatory or ethical domains that will require societal debate.
The paper notes that "collectively, the many government and official reports that constitute the node of this serious discourse can be and are accessed across most of the other nodes, although most official reports themselves only acknowledge and explicitly draw upon the technoscientific and business discourse nodes (as well as other official reports)."
Node 4: Social science and humanities research
Some early scholarly researchers from the social sciences and humanities have attempted to explore the social, economic, political, legal, religious, philosophical, and ethical implications of nanotechnology for human societies, but these researchers have not produced literatures yet, nor have they coalesced into functioning research communities. This discourse node is still in a very early stage of development, which can be seen in its almost entirely outward focus – rarely do the scattered writings cite other published scholarly works in the humanities and social sciences, in part because even as late as 2005 there is still little to be cited.
Node 5: Fiction writers
Fiction writers from early on have explored the potentials of nanotechnology, raising questions that have in some instances then been taken up in other nodes. Almost all of the emergent science fiction on nanotechnology has been based on the concerns of current science, even as it stretches any scientific consensus on what is plausible.
Node 6: Political activists
A good example for activist groups is ETC (the Action Group on Erosion, Technology and Concentration), a Canada-based activist group, which has produced a series of influential reports on the social implications of nanotechnology.
Activists – who have been politicized by policy debates over genetic modification of organisms – contribute in-depth reports, opinion pieces, and polemics to periodicals and mainstream media outlets such as the New York Times as well as to their own websites.
The varied activist reports and websites devoted to nanotechnology do monitor and respond to developments in Nodes 1 and 3, but with limited impact as yet on policy. It is primarily when their concerns get magnified through attention from the mainstream popular press that we see some acknowledgement from the technoscientists and government research-funding bodies.
Node 7: Science journalists and popular science writers
In terms of sheer volume, much of the writing in this category consists of short reports on current developments in nanotechnology. Much less common is critical journalism that looks at the current nanohype with any degree of skepticism. Just as research on the ethical implications of nanotechnology is scarce, as discussed for Node 4, reporting on the issue is generally confined to relatively brief statements about funding or legislative measures to deal with ethical issues.
Node 8: General public
The general public is, at best, dimly aware of the dimensions of nanotechnology, although the awareness is slowly growing, partly in response to initiatives taken by various governmental and nongovernmental groups. Although scant, the public’s view of nanotechnology probably differs from country to country, depending on national scientific aspirations and climate.
Implications
The authors make the interesting point that "it has long been well established by social scientists that technologies can be political – sometimes because certain technologies provide a convenient means of establishing patterns of power and authority, but sometimes because intractable properties of technologies are inherently linked to certain patterns of power and authority. It is certainly possible, perhaps likely, that the nanotechnology that emerges in coming years will have identifiable political qualities."
"That the power to define what is or what is not nanotechnology rests with technoscientists already points to a discursive power imbalance. It is this very power that privileges the technological aspects of a little-understood field over the social and cultural aspects. Riding piggy-back on this power of technoscientists are the captains of business and industry who are determined to capitalize on the lure of the label of nanotechnology."Munshi and his colleagues argue that "challenging the power imbalances implicit and explicit in society will require education of technoscientists, politicians, economists, lawyers, social scientists, school teachers, and indeed every citizen. Ignorance about the various facets and implications of progress in nanotechnology being widespread, a program of general education and information is essential in today’s industrial societie."

nanofabrication of armor Nature's bottom-up

nanofabrication of armor Nature's bottom-up .

Seashells are natural armor materials. The necessity for toughness arises because aquatic organisms are subject to fluctuating forces & impacts in the work of motion or through interaction with a moving surroundings. Nacre (mother-of-pearl), the pearly internal layer of plenty of mollusc shells, is the best example of a natural armor material that exhibits structural robustness, despite the brittle nature of their ceramic constituents. This material consists of about 95% inorganic aragonite with only a few percent of organic biopolymer by volume. New research at the university of South Carolina reveals the toughening secrets in nacre: rotation & deformation of aragonite nanograins absorb energy in the deformation of nacre. The aragonite nanograins in nacre are not brittle but deformable. The new findings may lead to the development of ultra-tough nanocomposites, for example for armor material, by realizing the rotation mechanism.

Super-tough and ultra-high temperature resistant materials are in critical need for applications under extreme conditions such as jet engines, power turbines, catalytic heat exchangers, military armors, aircrafts, and spacecrafts. Structural ceramics have largely failed to fulfill their promise of revolutionizing engines with strong materials that withstand very high temperature. The major problem with the use of ceramics as structural materials is their brittleness. Although many attempts have been made to increase their toughness, including incorporation of fibers, whiskers, or particles, and ZrO2 phase transformation toughening, currently available ceramics and their composites are still not as tough as metals and polymers. The brittleness of ceramic materials has not yet been overcome. It has proven difficult to solve this problem by conventional approaches.
On the other hand, Nature has evolved complex bottom-up methods for fabricating ordered nanostructured materials that often have extraordinary mechanical strength and toughness. One of the best examples is nacre. It has evolved through millions of years to a level of optimization not currently achieved in engineered composites.
This material has a brick-and-mortar-like structure with highly organized polygonal aragonite platelets of a thickness ranging from 200 to 500 nm and an edge length about 5 µm sandwiched with a 5-20 nm thick organic biopolymer interlayer, which assembles the aragonite platelets together. The combination of the soft organic biopolymer and the hard inorganic calcium carbonate produces a lamellar composite with a 2-fold increase in strength and a 1000-fold increase in toughness over its constituent materials.
Such remarkable properties have motivated many researchers to synthesize biomimetic nanocomposites that attempt to reproduce nature’s achievements and to understand the toughening and deformation mechanisms of natural nanocomposite materials.

Dr. Xiaodong Li, who heads the Nanostructures and Reliability Laboratory at the University of South Carolina, and his team have published papers that examine the role of nanostructures in the brilliant properties of nacre. In a first paper (" Nanoscale Structural and Mechanical Characterization of a Natural Nanocomposite Material: The Shell of Red Abalone"), the group reported the discovery of nanosized grains (particles) in nacre. However, the functionality of these aragonite nanograins was entirely unknown. Subsequently, lots of research groups asked: What roles do the nanoscale structures play in the inelasticity and toughening of nacre? Can they learn from this to produce nacre-like nanocomposites?
In a recent follow-up paper, Li and his group now reveal the functionality of these aragonite nanograins. The paper is titled "In Situ Observation of Nanograin Rotation and Deformation in Nacre", which appeared in the September 14, 2006 online edition of Nano Letters.
"To reveal the secret recipe of nacre is not an simple job" Li explains his research to Nanowerk. "We developed a micro-mechanical tester that can be used inside an atomic force microscope. They performed tensile and bending tests on nacre in situ where the nacre surface was imaged simultaneously by the atomic force microscope. The discoveries - rotation and deformation of aragonite nanograins clarify the earlier misunderstandings in modeling work, and provide a nanoscale modeling boundary condition. This opens up opportunities to create nacre-like ultra hard materials."
The grain rotation and deformation mechanisms in nacre aragonite platelets can be summarized by this figure:

On tension, the biopolymer between the nanograins is stretched in the tensile direction, which allows space for definite grains to rotate. Since the shape of these nanograins is normally irregular, the rotation of individual nanograins will push their neighbor grains apart, thereby leading to an increase in the spacing between the rotated nanograins and their neighbor grains (as shown in b).

With no outside applied strain/stress, nanograins with irregular shapes are originally packed closely by the biopolymer adhesives to form a sturdy structure (as shown in a).

The spacing behavior between the nanograins within an aragonite platelet causes the aragonite platelet to expand in the direction perpendicular to that of the applied strain/stress.
Schematics of grain rotation and deformation mechanisms in an aragonite platelet. D denotes grain deformation. The blue arrows denote the tensile direction. Green arrows denote the rotation direction of grains.(Reprinted with permission from the American Chemical Society)
The new findings are expected to revolutionize the way of preparing hard ceramic materials and structural parts, and will open up new application opportunities of ceramic materials and other materials as well.
Li points out that Nature has long been using bottom-up nanofabrication methods to form self-assembled nanomaterials that are much stronger and tougher than lots of manmade materials formed top-down.
"Mother Nature knows best" Li says. "Nature has evolved highly complex and elegant mechanisms for materials design and synthesis. Living organisms produce materials with physical properties that still surpass those of analogous synthetic materials with similar phase composition. They must turn our attention to Nature's designs and fabrication of materials. There is still a lot they must learn from Nature."