It’s time to revisit Nano Technology Safety (Nano-Safety)

Fifteen years ago (2006) there was a white paper published [Ref. 1] that addressed the need to create a structured approach to the handling and usage of nanomaterials.  As stated in the September 2013 blog on Nano-Safety, the primary issues involving nanotechnology is the concern for working with various materials whose properties are different and unknown from the bulk material.

“What is safety with respect to nanotechnology?  In the simplest terms, it is the development, manufacture, application, and control of nanomaterials in a manner that minimizes potential issues, both known and unknown that may impact both people and the environment.  All chemicals can kill one, it is just a matter of quantity.  Dangerous materials, even poisons, can be beneficial if applied in the proper dosage.  Just because something is dangerous does not mean it should not be used.  Fire is dangerous if mishandled, but does that mean we should not use it?

“One concern about safety in handling nanomaterials is based on the unknown issues.  Not knowing the impact on people or the environment can lead to unfounded concerns and a reluctance to accept developments.  This is not only true for nanomaterials but many commonly employed materials/processes when they were first introduced.  If you want to examine issues that have long had proponents and opponents, examine the application of milk pasteurization or the case of adding fluoride to drinking water.  

“In approaching this problem, … the issue of Nano-Safety can be addressed a systematic manner that involves 4 key concepts or pillars, which are: 1) Nanomaterial properties; 2) Impact on people and the environment; 3) Handling of nanomaterials; and, 4) Business focus.” [Ref. 2] 

The application of nanotechnology to health issues has seen significant developments along with related issues.  Gold nanoparticles have been employed to attach to cancer cells and then be irradiated by IR wavelength that pass harmlessly through skin but heat the gold and destroy the cancer cell that the particle is attached to.  Concerns can arise about the accumulation of the gold in the body.    

Fortunately, the tools available for investigation of the nanomaterials has been improving along with a better understanding of the interaction of nanomaterials with the human body.  

Research is approaching an interesting time.  Work is being done on nanosensors that can be connected to create a sense of “feeling” in prosthetics.  Graphene, of which research has been conducted, is now finding applications is material composite, where each layer is a single atom thick.  We are not close to large scale manufacturing – yet, but applications are being developed that promise to be able to reproduce some concepts of human feeling capabilities.  There is some work being done that could mitigate eye damage like Macular Degeneration. 

One issue that needs to be addressed is the impact of the new composites on people and the environment.  The process for long term evaluation and governmental approval is long.  This is especially true when considered to the half-life of startup companies. 

There is a need for a reevaluation of the existing guidelines for Nano-Safety and to create an update that is directed at nanotechnology and the medical environment.  The ability to expedite the development and application of nanotechnology in medical situation could provide a benefit for many.  This could be a 5th element of Nano-Safety.  More on this topic will be in future blogs.

References:

  1. Available at http://www.tryb.org/a_white_paper_on_nano-safety.pdf
  2. September 2013 blog http://www.nano-blog.com/?m=201309

Posted in Uncategorized

Let’s start 2021 out with a question.

In today’s technical reports, there are more references to Artificial Intelligence performing analyses of materials for developing an understanding of the properties of various combinations of materials at the nano-level structure.  Single layer materials are being combined with other single layer materials to produce various changes in the material properties that are not observed in the bulk realm.  As computer programs increase in complexity and capability, more and more materials are being evaluated for “interesting” characteristics. 

First consider the computers and the programs.  Prior to the mid-1980s, computers were large and relative slow.  Memory was expensive.  Expert Systems that were developed could not access large quantities of information, so the systems needed to have a table to reference its data.  The systems I built in the early 1980s used a matrix, like today’s spreadsheets, to reference probabilities of occurrences.  The system was designed to guide the worker in more quickly identifying the source of an issue.  After that specific source was identified, the worker entered the data, and the system updated the probabilities of occurrences.  An interesting observation was that employing this particular system at two different and not linked facilities provided different probabilities of occurrences at the different locations.  [References 1 & 2 are background on Expert Systems and Artificial Intelligence.  Wikipedia is also a good starting point.) 

It must be noted that there was a specialized computer developed based on MIT Artificial Intelligence that was identified as a LISP machine and had 36-bit operating system.  Interesting story [Ref. 3]

Today’s Artificial Intelligence programs have the ability to draw on a much larger database, can self-extract information from published materials, and can be programmed to continually run evaluations based on directed changes in the events/materials being selected.  While the field has grown in the Twenty-first century, there are some questions arising about the inability to prevent biases from being incorporated into the programming.  (Possibly something like the situation described about expert systems?) 

A saying that has been around for almost as long as computers is GIGO.  Garbage In, Garbage out!  The quality of the data is critical to the resultant output.  This takes us back to the application of Artificial Intelligence to evaluating novel materials.  The quality of the calculated material properties will be only as good as the data that the calculations are based upon.  There is no question that the working materials can be characterized fairly exactly.  The question is: “Do we know the material properties of absolutely pure materials?

Semiconductors are created by introducing a very small number of impurity atoms to change the characteristics of the base material.  The mathematics and the experimentation that provided the data is proven.  It works on the bulk scale.  But, what happens as the total amount of material under modification becomes smaller and smaller.  This is a serious question that needs to be answered.

In working with materials, the purity is specified.  99.99% pure is quite pure.  Six 9s is even better.  That is one part impurity in one million.  If one uses an approximation that there are 7 atoms of gold in one cubic nanometer, then there are 7 million gold atoms in a 100nm cubed sample, which implies 7 atoms that are not gold.  How does that change the properties of the material?  How do we purify gold or any other material to remove every extraneous atom?  Do we know the material properties of absolutely pure material?

References:

  1. https://azati.ai/the-return-of-expert-systems/
  2. https://www.parascript.com/blog/machine-learning-ai-vs-expert-systems-ai/
  3. https://en.wikipedia.org/wiki/Artificial_intelligence

Posted in Uncategorized

Developments as the Year ends

As technology moves more into the nano realm, interesting items are turning up.  Researchers at the University of Manchester, UK have found quasiparticles in a lattice of boron nitride with graphene in the middle and another layer of boron nitride [Ref. 1].  The definition of a quasiparticle is rather complex and can be described as a “phenomenon that occurs when a microscopically complicated system such as a solid behaves as if it contained different weakly interacting particles in vacuum” [Ref. 2].  If the comment is “so what”, the answer is interesting.  These phenomena provide the opportunity to create electronic properties that can be developed without needing to use chemical doping.  New type of semiconductors?

Gold particles have been employed to destroy cancerous cells due to the ability of the particles to rapidly heat when exposed to infrared radiation.  Attaching the nanoparticle to a particle that will be gathered by the cancer, enables the nano gold particles to accumulate at the cancerous site and be destroyed via IR heating.  Researchers at University of Cambridge and University of Leeds [Ref. 3] found that gold nanotubes can enter mesothelioma cells and subsequently destroy the cancerous cells whet the nanotubes are subjected to IR radiation.  The advantages of the nanotubes are that they can be tuned to absorb light at specific wavelengths.  There are two near-IR wavelengths that can easily penetrate skin tissue.  The tuning is accomplished by modifying the thickness of the nanotubes.  Another item in favor of this approach is that the nanotubes are created with similar dimensions to asbestos fibers.  So, the gold nanotubes should attach in similar places where the cancer and asbestos fibers are.

Nanyang Technological University in Singapore developed a green friendly, magnetically-activated glue technology [Ref. 4].  Typical operations in the fashion wear industry employ heat to activate glue that holds materials, like sport shoe components together.  Since the temperatures can range from 20 to 80C, it requires significant energy.  The researchers have added magnetic nanoparticles to adhesive material.  The magnetic field activates the adhesive and creates a bond as strong as obtained through heating.  This process uses much less energy and considering the size of the industry, could potentially save significant energy requirements. 

Japanese researchers have developed an ultra-thin sensor consisting of multilayers of conductive and dielectric nanomesh structures.  These structures when employed as an artificial skin patch does not affect the touch sensitivity beneath the patch [Ref. 5].  The challenge for creating the patch that transmits the sense of feeling is that there is a high density of sensors even over areas a small as 50 microns.  The patch must transmit the sense of touch while being flexible to follow the underlying skin structures.  The sensor developed consists of two porous layers.  The first layer is insulating and mesh-like while being in the range of 200 to 400nm thick.  The second layer is a capacitance network of lines.  The change in capacitance when the area experiences pressure provides the signal that translates into touch.

Wishing everyone a safe and prosperous New Year with great possibilities for interesting applications of nanotechnology.

References:

  1. https://physicsworld.com/a/new-family-of-quasiparticles-appears-in-graphene/?
  2. Dictionary.com  Quasiparticle
  3. https://physicsworld.com/a/gold-nanotubes-and-infrared-light-could-treat-asbestos-related-cancer/
  4. https://semiengineering.com/manufacturing-bits-dec-23-3/
  5. https://physicsworld.com/a/nanomesh-pressure-sensor-preserves-skins-sense-of-touch  

Posted in Uncategorized

Technology Roadmaps update & more unusual nano properties

In the June 2018 blog both the International Technology Roadmap for Semiconductors and the current International Roadmap for Devices and Systems were mentioned in a discussion of the need for roadmaps [Ref. 1].   As the semiconductor industry moves into the smaller single digit nanometers structures there are increasing challenges.  If one assumes that there needs to be a tolerance on 10% deviation from the straightness of the lines (it’s actually less), something new comes into play.    If one has a 3nm dimension, a 10% tolerance would imply a 0.3nm deviation.   The issue that will arise is that the dimensions of the molecules of material used to form the lines is roughly 0.5nm.  To achieve the 0.3nm tolerance would require being able to construct the arrangement of the molecules in such a manner that there would be no misalignment.  Two issues with this.  The first is that we do not have the technology to create such an exacting structure.  The second, and more important, is that we are unable to measure to this accuracy with the precision and speed required for manufacturing. 

In so research that was done at the University of Texas at Austin, there are some unusual properties observed.  A rotation of two layers of graphene by 1.12 degrees causes electrons to behave in strange ways.  [Ref. 2]  Electrons start moving 100 times more slowly than previously.  These strange properties of layered 2-D materials appears to result from interactions.  Part of this effort is directed at developing an understanding of high temperature superconductivity.  This concept was first identified theoretically and dismissed as not a real occurrence.  Due to the difficulty in developing and measuring an experiment, it was not expected to be demonstrated.  The researchers at the University of Texas developed an experimental configuration that permitted the evaluating an observation of the strange properties. 

Additional work has been published on using gold nanotubes and IR light to possible treat asbestos related cancer.  Work done at the University of Cambridge and the University of Leeds demonstrated that gold nanotubes tuned to have strong IR absorption and enter mesothelioma cells.  Heating the gold particles destroys the cancer.  Work on gold nanoparticles and IR heating for a method of destroying cancer cells has been ongoing since the early 2000s.  The application of the nanotubes permits the penetration of the mesothelioma cells.  So the attachment challenge can be solved.  IR radiation and gold nanoparticles is one method of destroying the cancer cells that has been proven.  With the ability to attach to the cancer provides the potential for a means of eliminating these specific cells. 

The last item in this month’s blog is not necessarily nano but intriguing.  Researchers at Simon Fraser University in Canada have created an experiment to demonstrate that hot water actually does freeze faster than cold water [Ref. 4].  While the actual experiment did not create the frozen water, the experiment demonstrated the process of molecule activity that leads to the conclusion that the warmer water has more molecular activity that causes the distribution of the warmer liquid to move more rapidly and distribute the temperature over a larger area more quickly than cold water. 

References:

  1. June 2018 blog http://www.nano-blog.com/?m=201806
  2. https://phys.org/news/2019-10-physics-magicangle-graphene-switchable.html
  3. https://physicsworld.com/a/gold-nanotubes-and-infrared-light-could-treat-asbestos-related-cancer/?utm_medium=email&utm_source=iop&utm_term=&utm_campaign=14258-48087&utm_content=Title%3A%20Gold%20nanotubes%20and%20infrared%20light%20could%20treat%20asbestos-related%20cancer%20%20-%20research_update&Campaign+Owner=
  4. https://physicsworld.com/a/experiments-pin-down-conditions-that-make-hot-water-freeze-before-cold/?utm_medium=email&utm_source=iop&utm_term=&utm_campaign=14290-46927&utm_content=Title%3A%20Experiments%20pin%20down%20conditions%20that%20make%20hot%20water%20freeze%20before%20cold%20%20-%20Editors_pick&Campaign+Owner=

Posted in Uncategorized

Nanotechnology gets even stranger

Nanotechnology is interesting.  When one starts to think that we have a reasonable knowledge of particle behavior, someone finds something new and interesting.  A basic assumption in thermodynamics is that objects change temperature (warming up or cooling down) at the same rate as a function of the environment of the particles.  Researchers at the Max Planck Institute of Biophysical Chemistry have predicted temperature change asymmetry based on mathematical models of confined nanoparticles [Ref. 1].  This modeling effort predicts that the motion of the warmer particles ends to bring them more quickly into the center of the probability distribution.  The researchers think that their results will improve the understanding of temperature change in nanoscale systems and provide insights into the Mpemba effect.  This phenomenon is the effect that warmer particles more quickly when its starting temperature is warmer.  They hope to confirm the theoretical results thought physical experiments. 

Researchers at the University of Arkansas have developed a graphene-based circuit, which they claim can produce clean power.  Their work appears to contradict Feynman’s theory that Brownian motion can not perform work.  The researchers contend that micron sized sheets of freestanding graphene move in a manner that is conducive to energy harvesting.    Their lab tests have indicated that freestanding sheets of graphene can generate an alternating current.  The researchers content that the thermal movement in the graphene is inherent in the material and not a result of temperature differential. 

Suhas Kumar of HP Labs, R. Stanley Williams at Texas A&M, and Ziwen Wang at Stanford have developed an electronic device that functions like a neuron.  The device combines resistance, capacitance, and Mott memristance. The most crucial part is the nanometers-thin niobium oxide (NbO2) layer.  (Note: Memristors are devices that hold memory based on the resistance of the current that has flowed through them. Mott memristors add the ability to incorporate any temperature-driven change in resistance.)  The structure of the material layers requires a high degree of precision.  The researchers developed the circuit through lengthy trial and error.

Most materials get thinner when they are stretched.  (A rubber band is a good example where it gets thinner as the length is elongated.)  Auxertic materials are different.  HELEN Gleeson, University of Leeds, has led research on auxertic materials that can be defined as material that also expands in one of the directions perpendicular to the elongation.  While these materials were originally formed in the 1970-80s, research into the development of synthetic auxetics ahs not been highly investigated.  The materials occur naturally in complex biomaterials.  Examples include human tendons.  Inorganic auxetics include copper, gold, and other face centric cubic materials.  When these materials are stretched, they undergo an internal reorganization, which forms voids that lowers the overall density.  The thoughts on potential applications include automotive windshields.  When an impact can cause a delamination between the various layers, incorporation of an auxertic could create an expansion where the base material undergoing an elongations and thinning.  This would increase the strength of the initial product.

As always, the world of nanotechnology provides unexpected insights into he property of materials at the nanorealm.

References:

  1. https://physicsworld.com/a/nanoparticles-warm-up-faster-than-they-cool-down/
  2. https://www.upi.com/Science_News/2020/10/02/Graphene-based-circuit-yields-clean-limitless-power/1571601661030/
  3. https://spectrum.ieee.org/nanoclast/semiconductors/devices/memristor-first-single-device-to-act-like-a-neuron?
  4. https://physicsworld.com/a/new-auxetic-material-stretches-the-limits/?

Posted in Uncategorized

Below nano gets more interesting

Last blog mentioned metallic hydrogen at a very small level.  As the computational power increases, we are able to examine (theoretically at least) the behavior of various materials.  There is a significant amount of effort being directed at the investigation of a new state of matter of metals, defined as “strange metals”, which actually involves understanding the behavior of the electrons.

The difference from traditional understanding of metals, is that “strange” metals have electrical resistance directly linked to its temperature.  The conductivity is linked to both Planck’s constant and Boltzmann’s constant.  [Ref. 1]  Planck’s constant establishes the energy a photon can have, while the Boltzmann constant is the relationship of the kinetic energy of particles in a gas with temperature of the gas. 

According to Reference 2, a robust computational model of “strange’ metals provided sufficient details to classify these “strange” metals existing in a new state of matter.  Their explanation of “strange” metals is that the name is generated base on the behavior of electrons in the metal.  In metals, electrons travel freely in the material with little resistance and few interactions.  “Strange” metal electrons are more restricted and slower moving that would be anticipated.  In effect, “strange” metals are not metal nor insulator.  The referenced article also employs the term “reluctant” metals.

This discovery is a result of research on high-temperature super-conductivity [Ref. 3]  In 1990, researchers discovered that cuprates have a strange behavior that does not vary with temperature as anticipated or as other high temperature super-conductors.  Current theory can explain superconducting  properties below 30 K, but that property up to temperatures of 130 K  was puzzling.  Fermi liquid theory predicts that at low temperatures, the metal resistance should depend on the square of the temperature.  Cuprates resistance varies linearly down to when they become superconducting.  This testing has been performed at a wide range of temperatures and with field strengths of up to 80 T (tesla).

Some research at TU Wien (Vienna University of Technology) is focused on developing higher temperature super conducting materials [Ref. 4].  They have been using ytterbium, rhodium, and silicon (YbRn2Si2), which is know for its “strange” properties.  They are using a new molecular beam epitaxy (MBE) process.  They build the layers of the material atomic layer by atomic layer.  (A side issue was to create the substrate for building the material.  Germanium turns out to be a geometrical match for the structure of the new material.  They have found that a sudden change in the carrier concentration induces the “strange” metal state.  Significant additional work needs to be done to understand the state of the materials before any development can proceed.

The implications of this work are many.  While the mention of super conductivity has been basis for projections of high speed transport via magnetic levitation, the increase in conductivity could increase the effective amount of electrical power for everyone.  Currently, the transmissions losses are significant and being able to almost eliminate the losses would effectively increase the electrical power available.  This type of application becoming mainstream is based on atomic level precision and methods of building materials layer by atomic layer.   That ability to create very large amounts of the material is still a few years in the future.  Tools need to be developed and techniques for measuring and evaluating the resultant materials need to be developed.  This is part of the continual search for new material properties starting at the atomic and nanometer sizes.   

References:

  1. https://newatlas.com/physics/strange-metals-new-state-of-matter/
  2. https://physicsworld.com/a/reluctant-metals-make-a-new-state-of-matter/
  3. https://physicsworld.com/a/strange-metals-become-even-stranger/
  4. https://www.eurekalert.org/pub_releases/2020-01/vuot-anl011620.php

Posted in Uncategorized

Interesting things

A couple thoughts on Hydrogen.  This might be old news to some, but two Harvard scientists have created metallic hydrogen [Ref. 1] by employing extreme pressures. This material is predicted to be metastable.  This implies that when the pressure is removed, the hydrogen will remain as a metal.  The example employed indicates that diamond, a metastable form of graphite, remains as a solid unless it is heated to a very  high temperature when I will revert to graphite.

This achievement has been pursued over the last century.  The possibility exists that the metallic hydrogen might possibly be a room temperature superconductor.   One advantage for propulsion systems is that metallic hydrogen should have more than three times the energy release than liquid hydrogen.   The work will continue without any short term promises of quantities of the material being available.

 An Indiana firm has a process for operating vehicles using hydrogen for fuel [Ref. 2].  It is currently retrofitting a truck for the city of Carmel, Indiana.  The process employed requires a less than one-hundred-pound metal box with a device that manufactures hydrogen, which is fed into the modified engine.  The critical component of this device contains six stainless steel canisters with a 113 gram “button” of aluminum and a gallium alloy.  A small amount of water drips onto the buttons creating a chemical reaction that separates the hydrogen and oxygen in the water.  The hydrogen is released and the oxygen forms aluminum oxide.  If the buttons are depleted, the truck will resort to traditional fuel. 

Many companies are experimenting with hydrogen powered vehicles.  The major issue is the availability of the hydrogen.  Plus, the majority of the hydrogen powered vehicles require a refueling that involves some form of liquid.  This limits the usability of hydrogen powered vehicles.  This “pellet” approach might provide a means of accelerating the application of hydrogen for a fuel.  The Residue of the product is water, which is not a pollutant. 

Back to ethics and integrity.  It seems that the news is full of contradicting information regarding the current COVID-19 pandemic.  There are medical reports that have been recalled due to questionable results and the researchers’ refusal to provide information about their experiments.  Politics has jumped into the fray with all sorts of blame for someone else.  The issue also consists of the fact that people listening to the statements either do not understand or do not actually read what is being presented.

 The Kansas state’s health secretary created a chart that demonstrated the State’s mask mandate appeared successful.  The figure below is the original presentation to the general public.  It compares the rolling average of daily cases per 100K population for mask usage and non-mask usage.  The gold line is the mask usage and the blue line is non-mask usage.  The blue line is relatively consistent while the gold line shows a very significant reduction.  The media publicized this information as proving the validity of requiring masks [Ref. 3]. 

There is only one problem.  The “y” axes are different for each of the variables.  The data for the “official” chart from the State was taken from the chart below.  The impression provided by the state official was erroneous in order to get people to fall for it.  It was uncovered and published by Wall Street Journal. 

The issue with creating false information is that the public starts to not believe anything that officials state as needed.  The medical profession has firmly stated that masks are not required and then decided they are required.  Certain medications are helpful and no they are not.  A vaccine will be developed, and everyone should have one even though long-term effects are unknown.  Herd immunity might only take 60% immunization to be effective, but all other types of immunizations required over 90%.  Researchers produce reports that are then retracted or not able to be verified.  Can anyone be believed? 

Without the ability to trust anyone, how does a society operate?  We must get back to ethics and integrity in all phase of civilized life.

References:

  1. https://getpocket.com/explore/item/holy-grail-metallic-hydrogen-is-going-to-change-everything
  2. https://spectrum.ieee.org/energywise/transportation/alternative-transportation/hydrogen-on-tapdevice-trucks-fuel-efficient-vehicles?utm_source=energywise&utm_medium=email&utm_campaign=energywise-05-06-20&mkt_tok=eyJpIjoiT0Rjd09UWTJaakJtTVRGbCIsInQiOiJ0MWNlVVdVVWdTWFNqRHJ0ZXkyRHFMb25NY2NMeXdqQkVKb2dRR1JzbXpjUFwvaHVISlZIWWlDck9KU0Q0dkRmZmFXeldwa2JKQ2FvS045R1FuWFowV05TZUwwZmZSZ3hTalJEVUN2dUJMbGNlMjJia244VGdOdEtUNWlGUXdyZ3AifQ%3D%3D
  3. https://www.wsj.com/articles/kansas-democrats-covid-chart-masks-the-truth-11598483406?mod=opinion_lead_pos10

Posted in Uncategorized

New Developments in the World of Nano

Tools: In previous blogs I have mentioned that to truly work at a small scale, one needs to be able to measure to at least a dimension that is one-tenth the size of what you are measuring.  Ideally, the capabilities should be two orders of magnitude smaller.  This has been a real problem with material in the low double digit and single digit nanometer scale.  There is a report [Ref. 1] from two researchers at UC Irvine have developed a methodology using a scanning transmission electron microscope to image charge density at sub-angstrom scales.  This is in the early stages of development and there are limitations on sample sizes and spatial resolution in their current equipment.  They project that learning from this initial effort will provide the direction for novel measurement capabilities.

So, what is the principle on how this development works? “Nearly all the physical properties of materials are determined by how electron charge is rearranged between nuclei when atoms aggregate together. Being able to directly visualize how electrons are distributed is therefore important. Compared to other diffraction methods, aberration-corrected STEM (AC-STEM) allows for atomic-scale imaging of a sample using an electron beam, or probe, focused to about half an angstrom in size. When electrons pass through the sample, they interact with the internal electric field in their path through the Lorentz force. This changes the beam’s momentum, which can then be measured by diffraction.” [Ref. 1]

 The researchers work with a composite material employing ferroelectric oxide bismuth ferrite and oxide strontium titanite as the insulator.  They did a raster scan of a surface area and acquired a diffraction pattern at each point on the sample.  They then employed this technique to visualize the charge transfer between the two materials.  With high resolution there were able to determine the local charge distribution, which provides information on the distribution of the positive ionic cores and the separation of the electrons.  [Full paper available in Ref. 2]

Materials: A concern with materials in applications that are subjected to very low temperatures is that metals shrink.  (This is the opposite effect that water has as it turns into ice.)  This is true for planes and requires using composites and/or alloys with opposing expansion properties to balance the shrinkage out.  Research being conducted at the U.S. DoE Brookhaven National Laboratories is exploring a metal that dramatically expands at low temperatures. [Ref. 3] Using samarium sulfide doped with impurities, they are delving into details of the material’s atomic structure and the electron-based origins of the materials negative thermal expansion. 

Unlike water, with a good explanation of the expansion properties, the cause of the expansion of samarium sulfide was unknown.  This particular compound can be formed into two different types depending on the external condition in developing the material.  The gold-colored variety of the compound is a conductor with electrons moving freely, while the black -colored one is a semiconductor.  The resultant investigations and theoretical calculations pointed to a Kondo effect.  This effect is that electrons will interact with magnetic impurities and in a material and align spin in the opposite direction of the larger magnetic particles to cancel their effect.  It appears that the completeness of the outer electron shell is critical.  It appears that the negative thermal expansion of samarium sulfide can be tuned by varying the amount of impurities.  The researchers indicated that samarium, thulium, and ytterbium should all have properties that can be useful.

References:

  1. https://physicsworld.com/a/4d-electron-microscopy-images-charge-density-at-sub-angstrom-scales/?
  2. https://www.nature.com/articles/s41586-019-1649-6
  3. https://www.aerodefensetech.com/component/content/article/adt/supplements/amm/insider/36779?utm_source=TB_Aero_News&utm_medium=email&utm_campaign=20200430&oly_enc_id=2682C9224356G9L

Posted in Uncategorized

Updates and Some Nanotechnology Developments

In doing research for an upcoming published paper, I ran across an interesting article.  In September 2019, a research article was published that postulated the worst case situation for a worldwide pandemic, of unknown origins, might have a devastating impact on the world.  This was the first annual report by the Global Preparedness Monitoring Board [Ref. 1].  This paper was published before the evidence of the coronavirus (COVID-19) was detected.  Consequently, these hypothetical findings were transferred to the projections of coronavirus impact.

In a related area, it appears that there are more instances of publications of faulty or purposely misleading scientific and medical research, even by prestigious researchers [Ref. 2, 3].  Whether it is researchers who refuse to provide details on their models or experts that have a segment of researchers in their field insisting on retracting papers, the overall effect is to build a distrust in any research that is published.  This will have serious consequences when the general public develops an attitude that all scientific pronouncements are not to be believed.

Back to nanotechnology.  A team from Binghamton University lead by Pu Zhang developed a liquid metal lattice material [Ref. 4].  The basic concept of the material is that a silicone shell holds the metal composite together, so the material can be crushed but is able to return to its original form.  The metal composite has a melting point of 62C, which enables a restructuring possible using heated water.  The concept relies on the shell to return to its original form.  Without that shell, the liquid metal would become a blob of metal.  In its solid form, the material is very strong and stable.  If is much more resistant to deformation than similar property-type polymers that are able to be reshaped.    

From Queensland University of Technology comes some computational studies that diamond-like carbon nanothreads could be employed in a strained mechanical battery system [Ref. 5].  As described in the referenced article: First described in 2015,  nanothreads joined a catalogue of carbon nanomaterials that have emerged over the past four decades. Nanothreads are 1D structures with carbon atoms linked by single bonds (like those in diamond) to three other carbon atoms and a hydrogen atom. Where the hydrogen atom is missing, the carbon atom may bond to a fourth carbon atom in an adjacent thread. This bonding contrasts with the hexagonal carbon lattices found in buckyballs, carbon nanotubes and graphene. In these materials, electron orbitals from each carbon atom are shared between just three other carbon atoms.” It is interesting to note that Penn State University has a National Science Foundation Center for Nanothread Chemistry.  There should be some interesting research coming from this new Center.

Medicine is moving into the nano realm to study and obtain insights about amyloid plaques [Ref. 6].  These amyloid plaques are characteristic of neurodegenerative diseases.  (Diseases like Parkinson’s and Alzheimer’s.)  These plaques are abnormal aggregates that have been linked to numerous diseases.  The goal of the research was to understand the structure of the plaques.  In order to accomplish their study, it required for the development of a new aspect of microscopy.  Their “super” resolution microscopy involves the latest in high resolution equipment with the addition of a dual channel polarized fluorescence light.  With their invention, they are able to observe the working of the molecules interacting with the plaques. 

There is the annual SEMICon West conference occurring next month (July).  This year it is virtual.  There will be a number of presentations on the issues/challenges as semiconductor devices have to overcome as the dimensions go lower into the single digit nanometers.  This is one area where nanotechnology is very much in the forefront of new developments.

References:

  1. https://apps.who.int/gpmb/assets/annual_report/GPMB_annualreport_2019.pdf
  2. https://www.wsj.com/articles/the-lancets-politicized-science-on-antimalarial-drugs-11591053222?mod=hp_opin_pos_3
  3. https://www.washingtontimes.com/news/2020/may/9/covid-19-puts-spotlight-science-scientists-often-l/
  4. https://physicsworld.com/a/new-material-could-be-used-to-make-a-liquid-metal-robot/?
  5. https://physicsworld.com/a/diamond-nanothreads-could-beat-batteries-for-energy-storage-theoretical-study-suggests/?
  6. https://physicsworld.com/a/super-resolution-microscopy-reveals-nanoscale-details-of-amyloid-protein-structures/?

Posted in Uncategorized

Research Impacts at the End of the Great Shutdown

As the world starts to come out of the Covid–19 shutdown, there are many things that will be required for research organizations to address prior to beginning their research again. Businesses have a similar but different process that needs to be completed as the organizations come out of the Great Shutdown. There are opportunities to reevaluate processes and procedures during the restart.

The items that need to be addressed from the research perspective include the workforce, equipment maintenance and calibration, material purity and integrity, and the validity of the most recent research. The initial consideration will include any new rules, regulations, and procedures the overall organization has developed and required to be implemented.  The challenge will be that all of these things need to be accomplished simultaneously. This is one of those times when a fast start may require additional assistance from recently retired personnel or external experts.

The workforce has several components that need to be addressed. The first one is the question of whether all personnel will be returning to the organization. It is possible that those not returning could have had a serious or deadly effect of Covid-19, still be recovering, found a new position, or have decided not to return to work until some later time. It is obvious that the new people who would need to be employed to replace people no longer available will require training. The returning people will need to go through a refresher training since it has been three months or more since they last use the equipment or processes, they will be working on. In addition, there may be regulations on social distancing that require changes in the workplace.

The equipment maintenance and calibration are an important part of any research effort. Since it has been months that the equipment has been non-operating, the equipment needs to have a thorough maintenance update. (I recall returning from a two-week shutdown to find that several of our wire binders had rust on parts of the mechanism. The temperature and humidity controlled rooms keep a level of moisture in the atmosphere all the time. We had to fix that before we can begin operating again.) After the equipment is up and running it will need to be calibrated. Since it has been months since its last operation, the equipment calibration should be the more thorough version to ensure the equipment is functioning properly.

While one normally does not think too much about the material purity or liquid contamination, these could be issues do to the long storage without usage. In previous blogs I have mentioned things like changing characteristics during shipment due to exposure to air. Liquids have the potential for dilution or contamination, which would change their characteristics when used in various processes. This requires some additional time to ensure the material you think you have is the material you actually have.

The last of these major points is the need to validate the research that was being done at the time of the Great Shutdown. Research that was not complete when the event happened needs to be redone from the very beginning. Research that had been completed shortly before the Great Shutdown needs to be replicated to ensure that the new experiments produces the same results as prior to the shutdown. The purpose of this extra effort is to ensure that something else in the workplace environment did not change and create an impact on the results that were obtained.

So, the real challenge is do everything at once and to do it is accurately as possible. In many cases the items will be done sequentially which will extend out the time for the completion of the research. Another portion of this time duration of lost research time is that it probably has a serious impact on the funds that were available for the research. This is one of the times in an organizations history that leading the way provide significant benefits. Being among the first, there are opportunities to pick up seasoned employees with skill levels that are greatly needed. Those organizations that start later may not have as wide a selection of skilled workers to choose from.

There are many more details that could be added to the startup of the research along with the actual startup of business. This could be a time to look at information flow, equipment priorities, hierarchical structure, equipment needs, and other items that would enable more accurate and faster research results. There will be strong competition within organizations for additional funding, so those who are prepared and move quickly will have an advantage. Good luck and God’s speed.

I do not provide an explicit email address due to that email address becoming overloaded with spam and advertising.  I can be reached via email: “ideas at nano-blog dot com”.  Replace the “at” and “dot” with the appropriate symbols. 

Posted in Uncategorized