The Second Cycle of Nanotechnology?

Posted on August 31, 2014 by Walt | Permalink 0

The time may be coming for nanotechnology to really take off. There are many descriptions of how technology become ingrained in the public perception. Most observations are based on the “business cycle” that relates to the profitability of developing a produce. There is also a cycle that relates to the application of technology and its acceptance by the general public.

The “business cycle” usually is described as an “S” curve. [Ref. 1] The initial phase of the effort requires considerable expenditure of funds to develop a product that meets the initial goals of the development effort. Assuming that is achieved, and many times it is not, then there is the development of a process to produce the ”technology” product. The acquisition by the early adopters will provide feedback for modifications. The level of acceptance will provide some feedback on whether the development will be a viable success. Assuming that this is progressing as desired, the organization will start recovering their investment and “making” money of this effort. After a period of time, the technology product matures and revenue stream diminishes until it is replaced by another product.

It is possible to ask a similar question about technology, in particular nanotechnology. Is there a cycle that relates to the technology itself? The initial one that comes to mind is the technology adoption lifecycle.   It is traditionally represented as a bell-curve that consists of innovators, early adaptors, early majority, late majority, and laggards. [Ref. 2] Another aspect is from observations on the web. Companies are measured by the length of time it takes to reach 100 million customers/clients/users. The faster the companies that “magic” number, the more perceived value it has. The “geeks” or “Techies” are normally very knowledgeable about developments, but it is not until the “mainstream” public becomes aware that “things” start to happen.

Recently, mid-August 2014, I was traveling on Alaska Airlines and picked up their Alaska Airlines Magazine. I was surprised to find an article on page 136 of the August issue entitled: Big Potential in Going Small” by Sally James. Her article is spread over 9 pages and can be found on line [Ref. 3]. It is a very good overview article that presents background information and some elements of current research efforts. It talks about the efforts ongoing at the University of Washington. The potential benefits of currently investigated applications are presented along with the possible dangers. This article has been receiving readership among the passengers of Alaska Airlines, which is not representative of the general population. However, one tends to read all the articles in an airline’s magazine to pass the time. Consequently, people would not read “tech” articles will be reading it.

The question to ponder is: Whether this article represents the start of another generation of articles on nanotechnology that will reach a wider portion of the general population and achieve the critical number of readers for nanotechnology to be understood and used by the majority of people?

 References:

[1] http://en.wikipedia.org/wiki/Technology_life_cycle

[2] http://en.wikipedia.org/wiki/Technology_adoption_lifecycle

[3] http://www.paradigmcg.com/digitaleditions/aam-0814/index.html  pages 136-150

Nanotechnology

PEER Review or Pier Review?

Posted on July 19, 2014 by Walt | Permalink 0

As has been stated previously, “scientific” research that can not be validated is not scientific and certainly not research according to the standards of accepted practice. I have stated that publications of reports in the new media that use words like “may”, “could”, “might” and many other conditionals should not have been published as scientific work because the comments obviously express the writer’s opinion of what he or she read or observed.

The one constant has been that if something is published in a peer reviewed publication, experts have reviewed it and made comments on the validity of the methodology, the thoroughness of the investigation, and the soundness of the conclusions. If modifications are needed, the author may need to resubmit the manuscript with changes for further review. Once through this process and published, the reader of the publication can understand that the information being presented is accurate.

Unfortunately, there has been a major revelation that a major scientific organization has been publishing research results that is presented as peer reviewed but is filled with many flaws and false information. [1]

What is involved in “peer” reviews? As a founding and past editor-in-chief of a peer reviewed publication, I have some experience with the process. Usually, a paper is submitted to the organization for review and publication. The paper is logged into a data base for tracking purposes. The paper normally has an abstract and a list of key words. The editor

If a summary or overview paper is requested for a special topic, the review process might be somewhat faster because it will not be presenting new research results and as a summary paper will not be totally comprehensive on all possible authors or related papers. It should cover the major topics. The review of this type of paper can be done by as few as two people plus the editor.

The assigned editor reviews the paper and makes a decision that includes: a) contents/topic acceptable for the publication; b) contents acceptable, but the format is not acceptable and the author will need to reformat the paper to fit the requirements of the publication before being considered; c) recommend that the paper be submitted to another publication; and, d) outright rejection due to inappropriate topic or sloppy work. If the work belongs in the publication, the editor sends the paper out for review. For research papers, ideally there are four reviewers assigned, although three can be acceptable as long as all return comprehensive reviews. There is normally a date provided for when the review need to be returned. In the vast majority of cases, the reviews are volunteers and receive no compensation for their work. With additional publication constantly being created, this causes a workload issue for reviewers. Typically, a reviewer would not receive more than two or three requests per year for peer reviewed papers.

The reviews are received and compiled by the editor. The comment are compiled anonymously and the critique of the paper is sent to the author with a recommendation. This normally falls into one of five categories. The first is publish unchanged. In more than ten years as editor-in-chief, I do not recall ever having a single paper where that occurred. The second category is publish with minor changes. The third is requiring a revision of a section or clarification of some section. This can be a restructuring of the contents to have an easier flow to subject and analysis, which I have occasionally done as a reviewer. This may or not require another pass through the peer review process. The fourth possibility is to require that the paper have additional work and/or additional sections added to the paper, which then must go through the peer review process again. The last category is to outright reject the paper for technical, research procedure, or other issues that invalidate the paper.

Some areas, such as new technological developments, can be challenging to find enough capable reviews for rapidly developing technologies. The editor has to be knowledgeable in the subject matter to be able to reach out to possible reviewers that possess the background to review the work. Anything short of this process is not a true peer review process.

From some of the published information on authors picking who reviews their papers does not provide confidence in the results. To me, it is like two researchers going down to a lake on a nice summer afternoon, having some beverages, and sitting on the pier talking about what would be good to publish. And, then publishing that result.

The problem with bad science is that people will believe it if it sounds credible. Legislatures will make regulations based on it. People in general will be subjected to the consequences coming from the bad science. This is especially true for an emerging field like nanotechnology. Where does that leave us? Basically, trust nothing that does not have peer reviews with sufficient details of the experiments, the results with all the data, and conclusions based on the preceding information.

References:

[1] http://online.wsj.com/articles/hank-campbell-the-corruption-of-peer-review-is-harming-scientific-credibility-1405290747

Misc Ramblings, Nanotechnology Risk Management

Nano Electronics

Posted on June 27, 2014 by Walt | Permalink 0

What actually is nano electronics?  The semiconductor people have been working with features that are 100 nm or smaller for close to 20 years.  The current generation of semiconductors are classified as being 32 nm or smaller.

So we have transistor and other components that are sub-100 nm.  Does that classify as nano-electronics?  Or are they nano-electronic components?  What classifies something as electronics?  Is it the function as a system or only constituent parts?  If the term refers to the system, the development of nanoscale electronics is significantly more challenging.

Consider the elements of a system.  The system must do something, whether it is measure a variable, record some data, provide an output, and survive in its environment.  Consider an electronic-based thermometer.  The device must measure temperature, which can be accomplished by a variety of means, current flow in thermally sensitive resistor, deflection of a gauge, etc.  Once the device makes this measurement, it must record the measurement or display it.  Of course, these electronics must be packaged in some kind of container.  Being electronics, the system requires power from somewhere.  It could be from a battery inside the package.  Let’s start with the existing state-of-the-art in small batteries.

Small batteries have been in the news this year.  NBCNews Technology [1] has a picture of a wireless medical implant that is roughly the size of a grain of rice.  The battery, which is part of the package, has a wireless connection capability for recharging it so that the device can be kept functioning.  ExtremeTech [2] has an article on graphene based battery that is also roughly the size of a grain of rice.  ScienceDaily [3] had an article on a battery small enough to be injected.  The picture in the article shows the battery to be about the length of a grain of rice but slightly larger in diameter.  From these and other releases, one can surmise that the length of a grain of rice is the smallest battery size in production today.

What are the dimensions of a grain of rice?  Rice grain are a function of two characteristics.  The first one is the length, which can range from under 6.2 mm for short grain to over 6.6 mm for long grain rice.  The second characteristic is the ratio of the length to the diameter.  This ranges from 3.1 for long grain to 1.9 for milled rice.  For an approximation, one can consider the grain of rice to be 6 mm by 2mm.  Consider that at the nanoscale.  The dimensions are 6,000,000 nm by 2,000,000 nm!  That is not small. And, that is only the battery not the rest of the electronics that needs to be included in the package.  Consequently, reducing the size of the power for the electronics will be a major challenge.  Other portions of the nano-electronics will be covered in future blogs.  We have a long way to go to get to true nanoscale electronic systems.

 

References:

[1] http://www.nbcnews.com/tech/innovation/woireless-medical-implan-smaller-grain-rice-n109431

[2] http://www.extremetech.com/extreme/176949-graphene-based-microbattery-could-power-biotelemetry-implants

[3] http://www.sciencedaily.com/releases/2014/02/140218143330.htm

Electronics, Nanotechnology

Nano-toxicity IS NOT Nano-Safety

Posted on June 7, 2014 by Walt | Permalink 0

There have been some recent mentions of nano-toxicity as being nanotechnology safety.  There are Government requests for review of proposed documents regarding either nano-safety or nano-toxicity.  The way these items are stated could lead a casual reader to the conclusion that the terms are identical.

The field of nano(technology or materials) toxicity relates to investigations into the impact of nanomaterials on humans or the environment that can create undesirable and/or unwanted effects.  Some of the effects are known to possibly occur after years of exposure or occur years after exposure.  Whether due to initial exposure or long-term exposure, the resulting harm can have a serious impact and the exposure needs to be eliminated or the effects mitigated.

Nano-toxicity investigates the impact through testing, which normally requires exposure to the substance in question and observations of the resultant effects on subjects.  In many cases these are done post-mortem.  Consequently, substitutes are employed to represent the impact on humans.  In order to expedite the evaluation, high dosages may be employed to imply the impact of smaller doses over a longer period of time.  A potential issue is that certain materials, like arsenic, may be acceptable at doses of low parts per million (ppm) but deadly at higher concentrations.  Large doses of inorganic arsenic containing 60 ppm or 60,000 parts per billion is toxic.  Smaller doses of 30 ppm will cause sickness along with other effects.  (These dosages are more than 10,000 times the amount found in most drinking water in the United States.)  The nature of arsenic has been known since ancient times [1].  There are some known long-term effects due to exposure.  Consequently, testing of arsenic effects does not increase the amount of exposure to shorten the time to determine its impact.

The methodology for testing creates an interesting situation.  If one assumes that creating a higher dosage will equate to the same effects as a lower dosage over a longer time, then increasing the arsenic dosage would correlate to a lower dosage over time.  From the report cited above, if one wanted to test the effect of 15 ppm and shorten the test duration, one could increase the dosage to 60 ppm or 75 ppm.  Obviously, this is not done because we have knowledge that the higher dose is fatal.  BUT, what if we don’t know the long term effect?  Can one safely assume that increasing the quantity of carbon nanotubes in the test animal provides an indication of long term effects of a lower dosage? Or, does the dosage cross a threshold quantity that becomes detrimental?  In many cases we can not answer that question.  Correlations are made to provide justifications for assumptions, but the absolute answer is not known.

In order to reduce the amount of testing, the use of grouping materials may be employed to determine its impact.  An early consideration, and still in use by many, is that any substance that was 100nm and smaller was considered nano.  In previous blogs, I have mentioned the reactive nature of aluminum nanoparticles.  There is a threshold that once crossed yields material that is highly reactive.  At 50 nm, the main concern of exposure to the aluminum nanoparticles is from the dust being inhaled.  However, at 30 nm, the same material becomes highly reactive and will explode in exposure to oxygen.  If I have a batch of aluminum nanoparticles that has a mean of 40 nm, what will happen?  It the half-width of the distribution is 1 nm, the results can be predicted.  If the half-width is 15 nm, it probably will have a different reaction.  But, both can be classified as a 40 nm particle distribution.  The ability to determine the half-width is not readily available.

Nano-toxicity is about the impact of nanomaterials on people and the environment.  It can not be all inclusive due to the immense number of possible combinations of materials.  The obvious question is: How do we handle the material?  That is not nano-toxicity.  Nano-Safety is.

Nano-Safety focuses on the measures, training, and procedures to create an environment where researchers/workers are able to evaluate situations and determine proper actions to mitigate potential dangers in the creation and handling of nanomaterials.  The next blog will address some of the progress that has been made in our Nano-Safety efforts.

References:

[1] http://www.atsdr.cdc.gov/phs/phs.asp?id=18&tid=3

 

Nanotechnology Health, Nanotechnology Safety

Graphene is a hot topic, but what are we missing?

Posted on May 24, 2014 by Walt | Permalink 0

Recent articles [1, 2, 3, 4] show that people are interested in producing graphene in many differ ways.  The referenced articles provide descriptions of various means of manufacturing graphene.  Reference 1 covers a few of the methods.  Slide 10 in reference 3 lists a number of suppliers with their manufacturing process listed.  There are a large number of other articles available on the manufacturing methods.

There is concern that there could be a safety issue in that a sheet of graphene can enter cells.  Reference 5 mentions that a thickness of less than 4 nm provides the ability to enter into cells.  Reference 6 states: “They found that the jagged edges of graphene nanoparticles, super sharp and super strong, easily pierced through cell membranes in human lung, skin and immune cells, suggesting the potential to do serious damage in humans and other animals.”  Let’s consider this issue.  First produced graphene has a small area and is normally attached to a carrier.  That gives it thickness that reduces or eliminates the possibility of being a cutting edge.  To be a source of danger, the graphene sample would need to be much larger than currently manufacturable.  If it were larger in area, does it retain its stiffness? Or does it tend to bend?  If it bends, does that reduce or eliminate the probability of being able to do damage?

To examine this from a different viewpoint, consider hydrogen.  As an element, it is the lightest.  Consequently, some of the early “lighter-than-air” devices were constructed with hydrogen as the lifting mechanism.  The unfortunate consequences of hydrogen’s reactivity with a proper stimulus is evidenced by the destruction of the von Hindenburg zeppelin.  In today’s environment of protect first on the real or imagined potential harm, work on using hydrogen would be strongly opposed.  This would have eliminated the possibility of hydrogen fueled vehicles.  The energy comes from the combination of hydrogen and oxygen, which yields power and water.  Knowing the reactivity of hydrogen, there are means of reducing the dangers of hydrogen as used in vehicles.  What will the application of graphene or carbon nanotubes yield that will provide benefit for humanity?

Reference 7 states: “All interesting nanomaterials have peculiar properties, and being declared hazardous does not doom a material, since many hazardous materials are already successfully used in semiconductor manufacturing, including lead, mercury, and cadmium.”  We must remember this in the development of any nanomaterial product and provide sufficient safety precautions.

With the strong emphasis on graphene, it raises the question: “Is this emphasis on graphene diverting attention on other similar materials?”  Graphene is a hot research topic, but there are other two-dimensional materials.  (Any three dimensional material that is only one atom thick is normally qualified as having no thickness or being two-dimensional. Among these materials are Boron Nitride, MoS2, Bi2Te3, Bi2Se3, with new ones being added regularly.)

There is another question that needs to be asked.  Assume that some of these developments are actually producible.  What are we going to do with them?  How will they make life better?

References:

[1] http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/high-quality-graphene-could-be-produced-in-bulk

[2] http://www.extremetech.com/extreme/180977-graphene-breakthrough-could-dramatically-reduce-cost-increase-production

[3] http://web.ornl.gov/adm/partnerships/events/Dec_Spark/Speight_Graphene%20v5.pdf

[4] http://gigaom.com/2014/05/23/graphene-production-could-scale-up-with-this-new-technique-out-of-mit/

[5] http://www.pnas.org/content/early/2013/07/09/1222276110.full.pdf

[6] http://www.gizmag.com/graphene-bad-for-environment-toxic-for-humans/31851/

[7] http://www.eetimes.com/document.asp?doc_id=1318965

Nanotechnology, Technology

Science and Bullying?

Posted on April 15, 2014 by Walt | Permalink 0

Are these two themes related?   There are claims that nanotechnology causes various types of diseases, can cause defects in humans and animals, and will cause long term issues in the environment.  (See previous blogs for some specific examples.)  There are more web sites that have “news” about nanotechnology or other technologies being harmful.  Usually, the recommendations are to stop employing the technologies or to ban the application or usage of the technologies.  The analyses in these reports carry terms like “feel”, “think”, “know”, “believe”, or similar verbiage without any supporting evidence.

Since the 17th century, there has been a method that employs “principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of the hypotheses” [1] with the dissemination of information in sufficient details that other experimenters can replicate the results.

The information that is available on the internet does not come with a pedigree.  The information needs to be viewed with a “buyer beware” sign.  This is not to say that the information is good or bad only that one needs to evaluate the source and the credibility of information.  The core idea that underpins science is “trust but verify.” [2] Results must be subject to challenges from experiment.  Unfortunately, the peer reviewed publications do not publish many papers that report failures in hypothesis testing.  This in turn creates the need to develop “positive” results for publications, which are necessary for promotion in many organizations.  What happens when there are published results that refute previously published papers?

With the widespread distribution of the internet, it is possible to attack the researcher and his/her credibility, or to hire researchers to create experiments that will produce the desired results.  The former may be done through character assassination in order to discredit the results.  The latter takes money, but for large companies with even larger money at stake, this is always an option.  There are a number of ways to attack this “problem” of results that one does not want considered.   Is this approach “bullying”?  You decide.

What is the impact on you?  Consider the two recent articles, one in USAToday [3] and the other in Forbes [4].  There has been a lot of confusion on the effects of vaccinations, with a number of opponents suggesting the some of the constituents are responsible for causing other diseases/illnesses.  There has been a number of very prominent statements made by various groups on these “dangers” of vaccinations.  The other view is that the vaccinations prevent the spread of common diseases.  The articles report on a different side of the effects.

Which is correct?  Is it possible that both sides have valid points?  Does it require that individuals review the facts and make individual decisions?  It is one thing to make a personal decision and a totally different one to insist that everyone follow the writer’s beliefs.  When we try to force people to do what we perceive as correct, is that not bullying?  Unfortunately, we seem to have lost the ability to have discussions or debates.  That means everyone needs to do more research and studying on pronouncements.  Remember the comment from earlier in the blog: “Trust but Verify”.

 

[1] http://www.merriam-webster.com/dictionary/scientific%20method

[2] http://www.economist.com/news/leaders/21588069-scientific-research-has-changed-world-now-it-needs-change-itself-how-science-goes-wrong

[3] http://www.usatoday.com/story/news/nation/2014/04/06/anti-vaccine-movement-is-giving-diseases-a-2nd-life/7007955/

[4] http://www.forbes.com/sites/emilywillingham/2014/04/05/chilis-autism-awareness-problem/

 

Nanotechnology Risk Management, Science

Nanotoxicity is NOT Nano-Safety

Posted on March 31, 2014 by Walt | Permalink 0

There are a number of comments and articles currently floating around that push the importance of Nanotoxicity.  First, I will raise my typical question.  Why does anyone care about a billionth toxicity?  To me, that sounds like something that is very safe.  When the prefix, in this case “nano”, is attached to a word, it is a modifier and changes the value of what it is modifying.  One can assume, but that is an assumption, that nanotoxicity actually is referring to nanomaterial toxicity or nanotechnology toxicity, but that requires making an assumption.

Toxicity refers to degree that a substance, chemical, material, etc., can create damage to an organism.  This impact can be on the entire organism or to a small subcomponent of it.  A key concept is that the effects are dose-dependent.  Everything can be dangerous when taken in too great a dose.  However, the opposite is also true.  There is a dose below which there is no observable effect.  This is true for chemical, biological, and other material (physical) items.  Consequently, toxicity addresses the effects based on predetermined doses.

Safety refers to “being safe.”  This implies that safety addresses situations where “non-safety” or harm could results.  It covers everything from personal safety (as in exposing one to dangerous situation where harm could occur) to providing a methodology for ensuring that any activity engaged in will not cause the individual (or environment) harm.  An example is “fire safety” where guidelines are created to prevent the occurrence of unwanted fire situation to the methodology to address the removal of an unwanted fire occurrence.

Nano-Safety or Nanotechnology Safety addresses the concept that considers the processes and procedures required to provide protection to people and the environment from possible applications that could involve a nanotechnology hazard.  The primary issue is that whether something is or is not a hazard may not be known for a number of years.  Consequently, the development of nano-safety education requires the development of methodologies that provide guidance in addressing situations where the material and its possible impact are unknown.  This can be likened to training people to fight various types of fires.  First one classifies the fire type, which then categorizes the possible methods to address the fire elimination.  A similar methodology is being developed in the courses at Texas State University, which was mentioned in a previous blog.

Nano-Toxicity is important to determine the potential issues with various nanomaterials and other nanothings.  The issue is that there is not sufficient time available to perform all the tests.  Since material properties change in the lower double digit nanometer range, how does one determine that the situation being addressed contains 30 nm aluminum particles and not 45 nm ones?  Since there can be many differences in the material size in a mixture, it is best to develop general procedures and apply them.  Nano-Toxicity is not Nano-Safety, but only a small component that can be employed in developing the Nano-Safety effort.

Nanotechnology Risk Management, Nanotechnology Safety

Nano Silver and Graphene

Posted on March 15, 2014 by Walt | Permalink 0

There are two separate topics in this blog: Nanosilver and Graphene.   Nanosilver is back in the news.  The headline from a recent web article [1] states: Research into nanosilver leads scientists to give warning.  It states that nanosilver can penetrate the skin and cause damage due to the formation of free radicals.  Since the formation free radicals have been linked to serious diseases such as Alzheimer’s and Parkinson’s.  A comment is also made that the research is at an early stage and has not shown how nanosilver might be absorbed.  However, they warn that supplements containing nanosilver should not be taken.

There are two points that need to be made.  First, the study has not demonstrated any correlation between the nanosilver and the creation of free-radicals that explicitly are related to diseases.  The supposition is that if A is related to B and a form of B can cause C, A will definitely cause C.  The second point is that this is not new.  An article, published in 2008 [2], titled: “Nanosilver disinfects – but at what price?” indicates that nanosilver might wreak havoc with the human immune system.  (Emphasis mine.)  This is the publication of work with wording that is picked up by publishers who ignore the completeness of the research in order to print headlines that will draw readers.

Graphene is still in the news.  There is a recent report from the University of Maryland titled: Tiny Origami Boxes Hold Promise for Energy Storage. [3] It is an interesting concept on increasing the density of hydrogen storage capacity.  {An interesting article on why electric vehicles will not go mainstream is in reference 4.)  Several car manufacturers have hydrogen fueled vehicles.  The issue is the storage capacity.  This could be a possible source of greater storage capacity.

There is a European project that aims to deliver industrial scale quantities of reinforced thermosetting polymers. [5]  The purpose of this effort is to produce industrial scale quantities for thermosetting polymers.  Graphene-Info announced a Graphene World Summit to address issues of standardization and commercialization. [6]  Finally, small is getting smaller.  Nanotechweb reported an “Atomic chisel chips away at graphene.” [7]  This link provides additional information on the ability to create smaller structures. Possibility other variations of the origami boxes?

References:

[1] http://www.cosmeticsdesign-europe.com/Formulation-Science/Research-into-nanosilver-leads-scientists-to-give-warning

[2] https://www.sciencenews.org/blog/science-public/nanosilver-disinfects-%E2%80%94-what-price

[3] http://www.umdrightnow.umd.edu/news/tiny-origami-boxes-hold-big-promise-energy-storage

[4] http://www.examiner.com/article/electric-cars-a-passing-fad

[5] http://www.graphene-info.com/new-european-project-aims-deliver-industrial-scale-quantities-graphene-reinforced-thermosetting

[6] http://www.graphene-info.com/smithers-apex-announces-first-graphene-world-summit

[7] http://nanotechweb.org/cws/article/tech/56426

Nanotechnology, Technology

Metamaterials

Posted on February 28, 2014 by Walt | Permalink 0

What are metamaterials?  Why are they important to nanotechnology?  There was a recent article in the IEEE Spectrum Magazine that addressed the customization of material structures [1].  Meta is from the Greek and means beyond or after.  Metamaterials are materials that exhibit properties that are not found in nature.  The current trend in metamaterials is the “invisibility cloaking” devices and wireless charging is a near term possible application [2].  There is an interesting depiction in the IEEE article showing what the effects of a negative index of refraction.     A key is the ability to custom build the material structure to provide the desired effect.

A question that always arises – at least to me – is what are the properties of 100% pure elements?  As we develop applications/products, there are specifications that we add to the purity of the materials being used, e.g., 99% or 99.9% pure material.  Why do we specify the purity?  We want to have a certain level of performance.  If we have circuits that require high levels of conductivity, we may move from one material to another, e.g., aluminum to copper.  There is always a trade-off.  Higher levels of purity might improve performance, but higher levels of purity are more expensive.  Consequently, switching to a higher conductivity material in semiconductors required developing a new process for depositing the copper.  When the cost of developing a new process is amortized over billions of devices, the initial high cost is not that significant as compared to higher material costs.

We currently insert doping atoms into materials to change the properties of materials and create materials that permit the control of electron flow.  Nature does the same thing.  Diamonds, which are a form of carbon, are normally clear (white).  However, if there are impurities in the carbon when the diamond was created the color can change to blue, yellow, or other colors.

There had been work, both theoretical and experimental, that has shown that some materials, silver and platinum, have a magnetic moment in 13 atom clusters.  If we add the fact that arrangements of atoms can create nanomaterials and these nanomaterials can aggregate (group together) and not merge into a larger nanomaterial or into the bulk material, there are opportunities to develop interesting applications.  This work has only started.  The future looks very interesting.

[1] http://spectrum.ieee.org/semiconductors/materials/how-to-make-a-better-invisibility-cloakwith-lasers

[2] http://www.businessinsider.com/metamaterials-invisibility-cloak-2013-12

Metamaterials

Nanotechnology and Future Bionics

Posted on February 6, 2014 by Walt | Permalink 0

There is a recent report [1] of an amputee with a bionic hand being able to feel texture and shape of objects in his grasp.  This was a month long test in Italy that has encouraged researchers on the ability to have control of the hand. Typically, there has been no sensation with the prosthesis and the user (wearer) could inadvertently crush objects instead of being able to hold or lift them.  There has been previous work that has connected prosthesis to a person nerves and enabled control and movement of the prosthesis, but the fine control has not been available.

The announcement released February 5, 2014 indicated that the study was led by Micera and Stanisa Raspopovic and colleagues at Switzerland’s Ecole Polytechnique Fédérale de Lausanne (EPFL) and the BioRobotics Institute in Pisa, Italy.  The scientist claim that this is the first time that an amputee had real-time sensory feeling from the prosthetic.  An interesting result was that even though the amputee had lost his hand over a decade previously, the sense of touch was reactivated.

The patient was blindfolded and had earplugs to test the capability of the artificial hand.  He was able to distinguish between a mandarin orange and a baseball.  He could also feel whether he was holding soft tissue, a hard piece of wood, or a flimsy plastic cup.  The implant, of the connections to the patient’s nerves, was removed after 30 days due to safety restrictions.  He returned to using his previous prosthesis, but without the sense of feeling.  The researchers project that it will be five years before some miniaturized version of the artificial hand will be available.  The current device is bulky due to the size of the electronics.

Where does nano fit in to this work?  What does our hands tell us?  It is more than hard and soft.  We are able to tell hot and cold.  Without that capability, we could put on hand down on a cooking burner.  There is a need for temperature sensing.  We can tell sharp and dull.  That capability is a function of the proximity of different sensors.  The same can be said for wet and dry.  The list of capabilities of the hand is long.  The work that was reported, while significant, is only the start.  If I consider the tip of a finger, how many sensors are required to determine temperature?  How many to distinguish sharp from dull?  How many to determine the differences between wet and dry or damp and dry?  How small do the sensors need to be?  Will they be significantly less than a micron?

Answering these questions leads to another.  How do to multiplex all these signals to the brain?  I think that we currently have the computing power to analyze the multiple signals coming from a finger or hand to determine conditions like hot or cold and only transmit the nerve impulse that indicates that condition.  It will take some years before the optimal condition of signal processing is determined, but the controller(s) will be receiving a large number of inputs from very small areas.  This will drive some of the connections into the nano realm.  One can envision one or more microprocessors embedded in the hand (arm) that provides all the major signal processing and relays a much simpler set of signals to the brain.

Scientific advances, like this one, open up more opportunities to develop solutions that take advantage of materials in the nano realm.

References:

[1] http://www.thelocal.ch/20140205/epfl-helps-pioneer-feeling-bionic-hand

Nanotechnology, Nanotechnology Health