Tag Archives: carbon nanotubes

What is a buckybomb?

I gather buckybombs have something to do with cancer treatments. From a March 18, 2015 news item on ScienceDaily,

In 1996, a trio of scientists won the Nobel Prize for Chemistry for their discovery of Buckminsterfullerene — soccer-ball-shaped spheres of 60 joined carbon atoms that exhibit special physical properties.

Now, 20 years later, scientists have figured out how to turn them into Buckybombs.

These nanoscale explosives show potential for use in fighting cancer, with the hope that they could one day target and eliminate cancer at the cellular level — triggering tiny explosions that kill cancer cells with minimal impact on surrounding tissue.

“Future applications would probably use other types of carbon structures — such as carbon nanotubes, but we started with Bucky-balls because they’re very stable, and a lot is known about them,” said Oleg V. Prezhdo, professor of chemistry at the USC [University of Southern California] Dornsife College of Letters, Arts and Sciences and corresponding author of a paper on the new explosives that was published in The Journal of Physical Chemistry on February 24 [2015].

A March 19, 2015 USC news release by Robert Perkins, which despite its publication date originated the news item, describes current cancer treatments with carbon nanotubes and this new technique with fullerenes,

Carbon nanotubes, close relatives of Bucky-balls, are used already to treat cancer. They can be accumulated in cancer cells and heated up by a laser, which penetrates through surrounding tissues without affecting them and directly targets carbon nanotubes. Modifying carbon nanotubes the same way as the Buckybombs will make the cancer treatment more efficient — reducing the amount of treatment needed, Prezhdo said.

To build the miniature explosives, Prezhdo and his colleagues attached 12 nitrous oxide molecules to a single Bucky-ball and then heated it. Within picoseconds, the Bucky-ball disintegrated — increasing temperature by thousands of degrees in a controlled explosion.

The source of the explosion’s power is the breaking of powerful carbon bonds, which snap apart to bond with oxygen from the nitrous oxide, resulting in the creation of carbon dioxide, Prezhdo said.

I’m glad this technique would make treatment more effective but I do pause at the thought of having exploding buckyballs in my body or, for that matter, anyone else’s.

The research was highlighted earlier this month in a March 5, 2015 article by Lisa Zynga for phys.org,

The buckybomb combines the unique properties of two classes of materials: carbon structures and energetic nanomaterials. Carbon materials such as C60 can be chemically modified fairly easily to change their properties. Meanwhile, NO2 groups are known to contribute to detonation and combustion processes because they are a major source of oxygen. So, the scientists wondered what would happen if NO2 groups were attached to C60 molecules: would the whole thing explode? And how?

The simulations answered these questions by revealing the explosion in step-by-step detail. Starting with an intact buckybomb (technically called dodecanitrofullerene, or C60(NO2)12), the researchers raised the simulated temperature to 1000 K (700 °C). Within a picosecond (10-12 second), the NO2 groups begin to isomerize, rearranging their atoms and forming new groups with some of the carbon atoms from the C60. As a few more picoseconds pass, the C60 structure loses some of its electrons, which interferes with the bonds that hold it together, and, in a flash, the large molecule disintegrates into many tiny pieces of diatomic carbon (C2). What’s left is a mixture of gases including CO2, NO2, and N2, as well as C2.

I encourage you to read Zynga’s article in whole as she provides more scientific detail and she notes that this discovery could have applications for the military and for industry.

Here’s a link to and a citation for the researchers’ paper,

Buckybomb: Reactive Molecular Dynamics Simulation by Vitaly V. Chaban, Eudes Eterno Fileti, and Oleg V. Prezhdo. J. Phys. Chem. Lett., 2015, 6 (5), pp 913–917 DOI: 10.1021/acs.jpclett.5b00120 Publication Date (Web): February 24, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

Spinal cords, brains, implants, and remote control

I have two items about implants and brains and an item about being able to exert remote control of the brain, all of which hint at a cyborg future for at least a few of us.

e-Dura, the spinal column, and the brain

The first item concerns some research, at the École Polytechnique de Lausanne (EPFL) which features flexible electronics. From a March 24, 2015 article by Ben Schiller for Fast Company (Note: Links have been removed),

Researchers at the Swiss Federal Institute of Technology, in Lausanne, have developed the e-Dura—a tiny skinlike device that attaches directly to damaged spinal cords. By sending out small electrical pulses, it stimulates the cord as if it were receiving signals from the brain, thus allowing movement.

“The purpose of the neuro-prosthesis is to excite the neurons that are on the spinal cord below the site of the injury and activate them, just like if they were receiving information from the brain,” says Stéphanie Lacour, a professor at the institute.

A January 8, 2015 (?) EPFL press release provides more information about the research,

EPFL scientists have managed to get rats walking on their own again using a combination of electrical and chemical stimulation. But applying this method to humans would require multifunctional implants that could be installed for long periods of time on the spinal cord without causing any tissue damage. This is precisely what the teams of professors Stéphanie Lacour and Grégoire Courtine have developed. Their e-Dura implant is designed specifically for implantation on the surface of the brain or spinal cord. The small device closely imitates the mechanical properties of living tissue, and can simultaneously deliver electric impulses and pharmacological substances. The risks of rejection and/or damage to the spinal cord have been drastically reduced. An article about the implant will appear in early January [2015] in Science Magazine.

So-called “surface implants” have reached a roadblock; they cannot be applied long term to the spinal cord or brain, beneath the nervous system’s protective envelope, otherwise known as the “dura mater,” because when nerve tissues move or stretch, they rub against these rigid devices. After a while, this repeated friction causes inflammation, scar tissue buildup, and rejection.

Here’s what the implant looks like,

Courtesy: EPFL

Courtesy: EPFL

The press release describes how the implant is placed (Note: A link has been removed),

Flexible and stretchy, the implant developed at EPFL is placed beneath the dura mater, directly onto the spinal cord. Its elasticity and its potential for deformation are almost identical to the living tissue surrounding it. This reduces friction and inflammation to a minimum. When implanted into rats, the e-Dura prototype caused neither damage nor rejection, even after two months. More rigid traditional implants would have caused significant nerve tissue damage during this period of time.

The researchers tested the device prototype by applying their rehabilitation protocol — which combines electrical and chemical stimulation – to paralyzed rats. Not only did the implant prove its biocompatibility, but it also did its job perfectly, allowing the rats to regain the ability to walk on their own again after a few weeks of training.

“Our e-Dura implant can remain for a long period of time on the spinal cord or the cortex, precisely because it has the same mechanical properties as the dura mater itself. This opens up new therapeutic possibilities for patients suffering from neurological trauma or disorders, particularly individuals who have become paralyzed following spinal cord injury,” explains Lacour, co-author of the paper, and holder of EPFL’s Bertarelli Chair in Neuroprosthetic Technology.

The press release goes on to describe the engineering achievements,

Developing the e-Dura implant was quite a feat of engineering. As flexible and stretchable as living tissue, it nonetheless includes electronic elements that stimulate the spinal cord at the point of injury. The silicon substrate is covered with cracked gold electric conducting tracks that can be pulled and stretched. The electrodes are made of an innovative composite of silicon and platinum microbeads. They can be deformed in any direction, while still ensuring optimal electrical conductivity. Finally, a fluidic microchannel enables the delivery of pharmacological substances – neurotransmitters in this case – that will reanimate the nerve cells beneath the injured tissue.

The implant can also be used to monitor electrical impulses from the brain in real time. When they did this, the scientists were able to extract with precision the animal’s motor intention before it was translated into movement.

“It’s the first neuronal surface implant designed from the start for long-term application. In order to build it, we had to combine expertise from a considerable number of areas,” explains Courtine, co-author and holder of EPFL’s IRP Chair in Spinal Cord Repair. “These include materials science, electronics, neuroscience, medicine, and algorithm programming. I don’t think there are many places in the world where one finds the level of interdisciplinary cooperation that exists in our Center for Neuroprosthetics.”

For the time being, the e-Dura implant has been primarily tested in cases of spinal cord injury in paralyzed rats. But the potential for applying these surface implants is huge – for example in epilepsy, Parkinson’s disease and pain management. The scientists are planning to move towards clinical trials in humans, and to develop their prototype in preparation for commercialization.

EPFL has provided a video of researcher Stéphanie Lacour describing e-Dura and expressing hopes for its commercialization,

Here’s a link to and a citation for the paper,

Electronic dura mater for long-term multimodal neural interfaces by Ivan R. Minev, Pavel Musienko, Arthur Hirsch, Quentin Barraud, Nikolaus Wenger, Eduardo Martin Moraud, Jérôme Gandar, Marco Capogrosso, Tomislav Milekovic, Léonie Asboth, Rafael Fajardo Torres, Nicolas Vachicouras, Qihan Liu, Natalia Pavlova, Simone Duis, Alexandre Larmagnac, Janos Vörös, Silvestro Micera, Zhigang Suo, Grégoire Courtine, Stéphanie P. Lacour. Science 9 January 2015: Vol. 347 no. 6218 pp. 159-163 DOI: 10.1126/science.1260318

This paper is behind a paywall.

Carbon nanotube fibres could connect to the brain

Researchers at Rice University (Texas, US) are excited about the possibilities that carbon nanotube fibres offer in the field of implantable electronics for the brain. From a March 25, 2015 news item on Nanowerk,

Carbon nanotube fibers invented at Rice University may provide the best way to communicate directly with the brain.

The fibers have proven superior to metal electrodes for deep brain stimulation and to read signals from a neuronal network. Because they provide a two-way connection, they show promise for treating patients with neurological disorders while monitoring the real-time response of neural circuits in areas that control movement, mood and bodily functions.

New experiments at Rice demonstrated the biocompatible fibers are ideal candidates for small, safe electrodes that interact with the brain’s neuronal system, according to the researchers. They could replace much larger electrodes currently used in devices for deep brain stimulation therapies in Parkinson’s disease patients.

They may also advance technologies to restore sensory or motor functions and brain-machine interfaces as well as deep brain stimulation therapies for other neurological disorders, including dystonia and depression, the researchers wrote.

A March 25, 2015 Rice University news release (also on EurekAlert*), which originated the news item, provides more details,

The fibers created by the Rice lab of chemist and chemical engineer Matteo Pasquali consist of bundles of long nanotubes originally intended for aerospace applications where strength, weight and conductivity are paramount.

The individual nanotubes measure only a few nanometers across, but when millions are bundled in a process called wet spinning, they become thread-like fibers about a quarter the width of a human hair.

“We developed these fibers as high-strength, high-conductivity materials,” Pasquali said. “Yet, once we had them in our hand, we realized that they had an unexpected property: They are really soft, much like a thread of silk. Their unique combination of strength, conductivity and softness makes them ideal for interfacing with the electrical function of the human body.”

The simultaneous arrival in 2012 of Caleb Kemere, a Rice assistant professor who brought expertise in animal models of Parkinson’s disease, and lead author Flavia Vitale, a research scientist in Pasquali’s lab with degrees in chemical and biomedical engineering, prompted the investigation.

“The brain is basically the consistency of pudding and doesn’t interact well with stiff metal electrodes,” Kemere said. “The dream is to have electrodes with the same consistency, and that’s why we’re really excited about these flexible carbon nanotube fibers and their long-term biocompatibility.”

Weeks-long tests on cells and then in rats with Parkinson’s symptoms proved the fibers are stable and as efficient as commercial platinum electrodes at only a fraction of the size. The soft fibers caused little inflammation, which helped maintain strong electrical connections to neurons by preventing the body’s defenses from scarring and encapsulating the site of the injury.

The highly conductive carbon nanotube fibers also show much more favorable impedance – the quality of the electrical connection — than state-of-the-art metal electrodes, making for better contact at lower voltages over long periods, Kemere said.

The working end of the fiber is the exposed tip, which is about the width of a neuron. The rest is encased with a three-micron layer of a flexible, biocompatible polymer with excellent insulating properties.

The challenge is in placing the tips. “That’s really just a matter of having a brain atlas, and during the experiment adjusting the electrodes very delicately and putting them into the right place,” said Kemere, whose lab studies ways to connect signal-processing systems and the brain’s memory and cognitive centers.

Doctors who implant deep brain stimulation devices start with a recording probe able to “listen” to neurons that emit characteristic signals depending on their functions, Kemere said. Once a surgeon finds the right spot, the probe is removed and the stimulating electrode gently inserted. Rice carbon nanotube fibers that send and receive signals would simplify implantation, Vitale said.

The fibers could lead to self-regulating therapeutic devices for Parkinson’s and other patients. Current devices include an implant that sends electrical signals to the brain to calm the tremors that afflict Parkinson’s patients.

“But our technology enables the ability to record while stimulating,” Vitale said. “Current electrodes can only stimulate tissue. They’re too big to detect any spiking activity, so basically the clinical devices send continuous pulses regardless of the response of the brain.”

Kemere foresees a closed-loop system that can read neuronal signals and adapt stimulation therapy in real time. He anticipates building a device with many electrodes that can be addressed individually to gain fine control over stimulation and monitoring from a small, implantable device.

“Interestingly, conductivity is not the most important electrical property of the nanotube fibers,” Pasquali said. “These fibers are intrinsically porous and extremely stable, which are both great advantages over metal electrodes for sensing electrochemical signals and maintaining performance over long periods of time.”

Here’s a link to and a citation for the paper,

Neural Stimulation and Recording with Bidirectional, Soft Carbon Nanotube Fiber Microelectrodes by Flavia Vitale, Samantha R. Summerson, Behnaam Aazhang, Caleb Kemere, and Matteo Pasquali. ACS Nano, Just Accepted Manuscript DOI: 10.1021/acsnano.5b01060 Publication Date (Web): March 24, 2015

Copyright © 2015 American Chemical Society

The paper is open access provided you register on the website.

Remote control for stimulation of the brain

Mo Costandi, neuroscientist and freelance science writer, has written a March 24, 2015 post for the Guardian science blog network focusing on neuronal remote control,

Two teams of scientists have developed new ways of stimulating neurons with nanoparticles, allowing them to activate brain cells remotely using light or magnetic fields. The new methods are quicker and far less invasive than other hi-tech methods available, so could be more suitable for potential new treatments for human diseases.

Researchers have various methods for manipulating brain cell activity, arguably the most powerful being optogenetics, which enables them to switch specific brain cells on or off with unprecedented precision, and simultaneously record their behaviour, using pulses of light.

This is very useful for probing neural circuits and behaviour, but involves first creating genetically engineered mice with light-sensitive neurons, and then inserting the optical fibres that deliver light into the brain, so there are major technical and ethical barriers to its use in humans.

Nanomedicine could get around this. Francisco Bezanilla of the University of Chicago and his colleagues knew that gold nanoparticles can absorb light and convert it into heat, and several years ago they discovered that infrared light can make neurons fire nervous impulses by heating up their cell membranes.

Polina Anikeeva’s team at the Massachusetts Institute of Technology adopted a slightly different approach, using spherical iron oxide particles that give off heat when exposed to an alternating magnetic field.

Although still in the experimental stages, research like this may eventually allow for wireless and minimally invasive deep brain stimulation of the human brain. Bezanilla’s group aim to apply their method to develop treatments for macular degeneration and other conditions that kill off light-sensitive cells in the retina. This would involve injecting nanoparticles into the eye so that they bind to other retinal cells, allowing natural light to excite them into firing impulses to the optic nerve.

Costandi’s article is intended for an audience that either understands the science or can deal with the uncertainty of not understanding absolutely everything. Provided you fall into either of those categories, the article is well written and it provides links and citations to the papers for both research teams being featured.

Taken together, the research at EPFL, Rice University, University of Chicago, and Massachusetts Institute of Technology provides a clue as to how much money and intellectual power is being directed at the brain.

* EurekAlert link added on March 26, 2015.

Carbon nanotube commercialization report from the US National Nanotechnology Initiative

Apparently a workshop on the topic commercializing carbon nanotubes was held in Washington, DC. in Sept. 2014. A March 12, 2015 news item on Nanowerk (originated by  March 12, 2015 US National Nanotechnology Initiative news release on EurekAlert) announces the outcome of that workshop (Note: Links have been removed),

The National Nanotechnology Initiative today published the proceedings of a technical interchange meeting on “Realizing the Promise of Carbon Nanotubes: Challenges, Opportunities, and the Pathway to Commercialization” (pdf), held at the National Aeronautics and Space Administration (NASA) Headquarters on September 15, 2014. This meeting brought together some of the Nation’s leading experts in carbon nanotube materials to identify, discuss, and report on technical barriers to the production of carbon nanotube (CNT)-based bulk and composite materials with properties that more closely match those of individual CNTs and to explore ways to overcome these barriers.

The outcomes of this meeting, as detailed in this report, will help inform the future directions of the NNI Nanotechnology Signature Initiative “Sustainable Nanomanufacturing: Creating the Industries of the Future”, which was launched in 2010 to accelerate the development of industrial-scale methods for manufacturing functional nanoscale systems.

The Technical Interchange Proceedings ‘Realizing the Promise of Carbon Nanotubes: Challenges, Opportunities, and the Pathway to Commercialization‘ (30 pp. PDF) describes areas for improvement in its executive summary,

A number of common themes and areas requiring focused attention were identified:

● Increased efforts devoted to manufacturing, quality control, and scale-up are needed. The development of a robust supply of CNT bulk materials with well-controlled properties would greatly enhance commercialization and spur use in a broad range of applications.
● Improvements are needed in the mechanical and electrical properties of CNT-based bulk materials (composites, sheets, and fibers) to approach the properties of individual CNTs. The development of bulk materials with properties nearing ideal CNT values would accelerate widespread adoption of these materials.
● More effective use of simulation and modeling is needed to provide insight into the fundamentals of the CNT growth process. Theoretical insight into the fundamentals of the growth process will inform the development of processes capable of producing high-quality material in quantity.
● Work is needed to help develop an understanding of the properties of bulk CNT-containing materials at longer length scales. Longer length scale understanding will enable the development of predictive models of structure–process–properties relationships and structural design technology tailored to take advantage of CNT properties.
● Standard materials and protocols are needed to guide the testing of CNT-based products for commercial applications. Advances in measurement methods are also required to characterize bulk CNT material properties and to understand the mechanism(s) of failure to help ensure material reliability.
● Life cycle assessments are needed for gauging commercial readiness. Life cycle assessments should include energy usage, performance lifetime, and degradation or disposal of CNT-based products.
● Collaboration to leverage resources and expertise is needed to advance commercialization of CNT-based products. Coordinated, focused efforts across academia, government laboratories, and industry to target grand challenges with support from public–private partnerships would accelerate efforts to provide solutions to overcome these technical barriers.

This meeting identified a number of the technical barriers that need to be overcome to make the promise of carbon nanotubes a reality. A more concerted effort is needed to focus R&D activities towards addressing these barriers and accelerating commercialization. The outcomes from this meeting will inform the future directions of the NNI Nanomanufacturing Signature Initiative and provide specific areas that warrant broader focus in the CNT research community. [p. vii print; p. 9 PDF]

This report, in its final section, explains the basis for the interest in and the hopes for carbon nanotubes,

Improving the electrical and mechanical properties of bulk carbon nanotube materials (yarns, fibers, wires, sheets, and composites) to more closely match those of individual carbon nanotubes will enable a revolution in materials that will have a broad impact on U.S. industries, global competitiveness, and the environment. Use of composites reinforced with high-strength carbon nanotube fibers in terrestrial and air transportation vehicles could enable a 25% reduction in their overall weight, reduce U.S. oil consumption by nearly 6 million barrels per day by 2035 [42], and reduce worldwide consumption of petroleum and other liquid fuels by 25%. This would result in the reduction of CO2 emissions by as much as 3.75 billion metric tons per year. Use of carbon nanotube-based data and power cables would lead to further reductions in vehicle weight, fuel consumption, and CO2 emissions. For example, replacement of the copper wiring in a Boeing 777 with CNT data and power cables that are 50% lighter would enable a 2,000-pound reduction in airplane weight. Use of carbon nanotube wiring in power distribution lines would reduce transmission losses by approximately 41 billion kilowatt hours annually [42], leading to significant savings in coal and gas consumption and reductions in the electric power industry’s carbon footprint.

The impact of developing these materials on U.S. global competitiveness is also significant. For example, global demand for carbon fibers is expected to grow from 46,000 metric tons per year in 2011 to more than 153,000 metric tons in 2020 due to the exponential growth in the use of composites in commercial aircraft, automobiles, aerospace, and wind energy [43]. Ultrahigh-strength CNT fibers would be highly attractive in each of these applications because they offer the advantage of reduced weight and improved performance over conventional carbon fibers. [p. 10 print; p. 20 PDF]

As these things go, this is a very short document, which makes it a fast read, and it has a reference list, something I always find useful.

My colleague, Dexter Johnson in a March 17, 2015 posting on his Nanoclast blog (on the IEEE [Institute for Electrical and Electronics Engineers] website) provides some background information before launching into an analysis of the report’s recommendations (Note: Links have been removed),

In the last half-a-decade we have witnessed once-beloved carbon nanotubes (CNTs) slowly being eclipsed by graphene as the “wonder material” of the nanomaterial universe.

This changing of the guard has occurred primarily within the research community, where the amount of papers being published about graphene seems to be steadily increasing. But in terms of commercial development, CNTs still have a leg up on graphene, finding increasing use in creating light but strong composites. Nonetheless, the commercial prospects for CNTs have been taking hits recently, with some producers scaling down capacity because of lack of demand.

With this as the backdrop, the National Nanotechnology Initiative (NNI), famous for its estimate back in 2001 that the market for nanotechnology will be worth $1 trillion by 2015,  has released a report based on a meeting held last September. …

I recommend reading Dexter’s analysis.

Self-organizing nanotubes and nonequilibrium systems provide insights into evolution and artificial life

If you’re interested in the second law of thermodynamics, this Feb. 10, 2015 news item on ScienceDaily provides some insight into the second law, self-organized systems, and evolution,

The second law of thermodynamics tells us that all systems evolve toward a state of maximum entropy, wherein all energy is dissipated as heat, and no available energy remains to do work. Since the mid-20th century, research has pointed to an extension of the second law for nonequilibrium systems: the Maximum Entropy Production Principle (MEPP) states that a system away from equilibrium evolves in such a way as to maximize entropy production, given present constraints.

Now, physicists Alexey Bezryadin, Alfred Hubler, and Andrey Belkin from the University of Illinois at Urbana-Champaign, have demonstrated the emergence of self-organized structures that drive the evolution of a non-equilibrium system to a state of maximum entropy production. The authors suggest MEPP underlies the evolution of the artificial system’s self-organization, in the same way that it underlies the evolution of ordered systems (biological life) on Earth. …

A Feb. 10, 2015 University of Illinois College of Engineering news release (also on EurekAlert), which originated the news item, provides more detail about the theory and the research,

MEPP may have profound implications for our understanding of the evolution of biological life on Earth and of the underlying rules that govern the behavior and evolution of all nonequilibrium systems. Life emerged on Earth from the strongly nonequilibrium energy distribution created by the Sun’s hot photons striking a cooler planet. Plants evolved to capture high energy photons and produce heat, generating entropy. Then animals evolved to eat plants increasing the dissipation of heat energy and maximizing entropy production.

In their experiment, the researchers suspended a large number of carbon nanotubes in a non-conducting non-polar fluid and drove the system out of equilibrium by applying a strong electric field. Once electrically charged, the system evolved toward maximum entropy through two distinct intermediate states, with the spontaneous emergence of self-assembled conducting nanotube chains.

In the first state, the “avalanche” regime, the conductive chains aligned themselves according to the polarity of the applied voltage, allowing the system to carry current and thus to dissipate heat and produce entropy. The chains appeared to sprout appendages as nanotubes aligned themselves so as to adjoin adjacent parallel chains, effectively increasing entropy production. But frequently, this self-organization was destroyed through avalanches triggered by the heating and charging that emanates from the emerging electric current streams. (…)

“The avalanches were apparent in the changes of the electric current over time,” said Bezryadin.

“Toward the final stages of this regime, the appendages were not destroyed during the avalanches, but rather retracted until the avalanche ended, then reformed their connection. So it was obvious that the avalanches correspond to the ‘feeding cycle’ of the ‘nanotube inset’,” comments Bezryadin.

In the second relatively stable stage of evolution, the entropy production rate reached maximum or near maximum. This state is quasi-stable in that there were no destructive avalanches.

The study points to a possible classification scheme for evolutionary stages and a criterium for the point at which evolution of the system is irreversible—wherein entropy production in the self-organizing subsystem reaches its maximum possible value. Further experimentation on a larger scale is necessary to affirm these underlying principals, but if they hold true, they will prove a great advantage in predicting behavioral and evolutionary trends in nonequilibrium systems.

The authors draw an analogy between the evolution of intelligent life forms on Earth and the emergence of the wiggling bugs in their experiment. The researchers note that further quantitative studies are needed to round out this comparison. In particular, they would need to demonstrate that their “wiggling bugs” can multiply, which would require the experiment be reproduced on a significantly larger scale.

Such a study, if successful, would have implications for the eventual development of technologies that feature self-organized artificial intelligence, an idea explored elsewhere by co-author Alfred Hubler, funded by the Defense Advanced Research Projects Agency [DARPA]. [emphasis mine]

“The general trend of the evolution of biological systems seems to be this: more advanced life forms tend to dissipate more energy by broadening their access to various forms of stored energy,” Bezryadin proposes. “Thus a common underlying principle can be suggested between our self-organized clouds of nanotubes, which generate more and more heat by reducing their electrical resistance and thus allow more current to flow, and the biological systems which look for new means to find food, either through biological adaptation or by inventing more technologies.

“Extended sources of food allow biological forms to further grow, multiply, consume more food and thus produce more heat and generate entropy. It seems reasonable to say that real life organisms are still far from the absolute maximum of the entropy production rate. In both cases, there are ‘avalanches’ or ‘extinction events’, which set back this evolution. Only if all free energy given by the Sun is consumed, by building a Dyson sphere for example, and converted into heat then a definitely stable phase of the evolution can be expected.”

“Intelligence, as far as we know, is inseparable from life,” he adds. “Thus, to achieve artificial life or artificial intelligence, our recommendation would be to study systems which are far from equilibrium, with many degrees of freedom—many building blocks—so that they can self-organize and participate in some evolution. The entropy production criterium appears to be the guiding principle of the evolution efficiency.”

I am fascinated

  • (a) because this piece took an unexpected turn onto the topic of artificial life/artificial intelligence,
  • (b) because of my longstanding interest in artificial life/artificial intelligence,
  • (c) because of the military connection, and
  • (d) because this is the first time I’ve come across something that provides a bridge from fundamental particles to nanoparticles.

Here’s a link to and a citation for the paper,

Self-Assembled Wiggling Nano-Structures and the Principle of Maximum Entropy Production by A. Belkin, A. Hubler, & A. Bezryadin. Scientific Reports 5, Article number: 8323 doi:10.1038/srep08323 Published 09 February 2015

Adding to my delight, this paper is open access.

Multi-walled carbon nanotubes and blood clotting

There’s been a lot of interest in using carbon nanotubes (CNTs) for biomedical applications such as drug delivery. New research from Trinity College Dublin (TCD) suggests that multi-walled carbon nanotubes (MWCNTs) may have some limitations when applied to biomedical uses. From a Jan. 20, 2014 news item on Nanowerk (Note: A link has been removed),

Scientists in the School of Pharmacy and Pharmaceutical Sciences in Trinity College Dublin, have made an important discovery about the safety issues of using carbon nanotubes as biomaterials which come into contact with blood. The significance of their findings is reflected in their paper being published as the feature story and front page cover of the international, peer-reviewed journal Nanomedicine (“Blood biocompatibility of surface-bound multi-walled carbon nanotubes”).

A Jan. 19, 2015 TCD press release, which originated the news item, offers a good description of the issues around blood clotting and the research problem (nonfunctionalized CNTs and blood compartibility) the scientists were addressing (Note: Links have been removed),

When blood comes into contact with foreign surfaces the blood’s platelets are activated which in turn leads to blood clots being formed. This can be catastrophic in clinical settings where extracorporeal circulation technologies are used such as during heart-lung bypass, in which the blood is circulated in PVC tubing outside the body. More than one million cardiothoracic surgeries are performed each year and while new circulation surfaces that prevent platelet activation are urgently needed, effective technologies have remained elusive.

One hope has been that carbon nanotubes, which are enormously important as potentially useful biomedical materials, might provide a solution to this challenge and this led the scientists from the School of Pharmacy and Pharmaceutical Sciences in collaboration with Trinity’s School of Chemistry and with colleagues from UCD and the University of Michigan in Ann Arbour to test the blood biocompatibility of carbon nanotubes. They found that the carbon nanotubes did actually stimulate blood platelet activation, subsequently leading to serious and devastating blood clotting. The findings have implications for the design of medical devices which contain nanoparticles and which are used in conjunction with flowing blood.

Speaking about their findings, Professor Marek Radomski, Chair of Pharmacology, Trinity and the paper’s senior author said: “Our results bear significance for the design of blood-facing medical devices, surface-functionalised with nanoparticles or containing surface-shedding nanoparticles. We feel that the risk/benefit ratio with particular attention to blood compatibility should be carefully evaluated during the development of such devices. Furthermore, it is clear that non-functionalised carbon nanotubes both soluble and surface-bound are not blood-compatible”.

The press release also quotes a TCD graduate,

Speaking about the significance of these findings for Nanomedicine research, the paper’s first author Dr Alan Gaffney, a Trinity PhD graduate who is now Assistant Professor of Anaesthesiology in Columbia University Medical Centre, New York said: “When new and exciting technologies with enormous potential benefits for medicine are being studied, there is often a bias towards the publication of positive findings. [emphasis mine] The ultimate successful and safe application of nanotechnology in medicine requires a complete understanding of the negative as well as positive effects so that un-intended side effects can be prevented. Our study is an important contribution to the field of nanomedicine and nanotoxicology research and will help to ensure that nanomaterials that come in contact with blood are thoroughly tested for their interaction with blood platelets before they are used in patients.”

Point well taken Dr. Gaffney. Too often there’s an almost euphoric quality to the nanomedicine discussion where nanoscale treatments are described as if they are perfectly benign in advance of any real testing. For example, I wrote about surgical nanobots being used in a human clinical trial in a Jan. 7, 2015 post which features a video of the researcher ‘selling’ his idea. The enthusiasm is laudable and necessary (researchers work for years trying to develop new treatments) but as Gaffney notes there needs to be some counter-ballast and recognition of the ‘positive bias’ issue.

Getting back to the TCD research, here’s a link to and a citation for the paper (or counter-ballast),

Blood biocompatibility of surface-bound multi-walled carbon nanotubes by Alan M. Gaffney, MD, PhD, Maria J. Santos-Martinez, MD, Amro Satti, Terry C. Major, Kieran J. Wynne, Yurii K. Gun’ko, PhD, Gail M. Annich, Giuliano Elia, Marek W. Radomski, MD. January 2015 Volume 11, Issue 1, Pages 39–46 DOI: http://dx.doi.org/10.1016/j.nano.2014.07.005 Published Online: July 26, 2014

This paper is open access.

Acoustics and carbon nanotubes

Mikhail Koslov from the University of Texas at Dallas has written a Dec. 18, 2014 Nanowerk Spotlight article about his research into carbon nanotubes and their acoustic properties,

Carbon nanotube assemblies enabled design of a hybrid thermo-electromagnetic sound transducer with unique sound generation features that are not available from conventional diaphragm and thermo-acoustic speakers.

EM image of multi-walled carbon nanotube sheet used for thermo-electromagnetic sound transducer. (Image: Mikhail Kozlov, University of Texas at Dallas)

EM image of multi-walled carbon nanotube sheet used for thermo-electromagnetic sound transducer. (Image: Mikhail Kozlov, University of Texas at Dallas)

Kozlov goes on to explain his work in more detail,

… a hybrid thermo-electromagnetic sound transducer (TEMST) [was] fabricated using highly porous multi-walled carbon nanotube sheet that was placed in the proximity of a permanent magnet. Upon electrical AC excitation, thermal response of the material is combined with diaphragm-like sheet oscillations induced by the electromagnetic action of the Lorentz force.

Unlike conventional diaphragm loudspeaker, acoustic spectrum of the TEMST device consists of a superposition of TA and EM responses that can be altered by applied bias voltage. Variation of bias voltage changes spectral intensity and spatial distribution of generated sound.

In particular, propagation direction of the sound can be reversed by switching bias polarity that somewhat resembles voltage-controlled acoustic reflection. Such uncommon behavior was explained by interference of the two contributions being beneficial for diverse sound management applications.

It was found also that amplitude of first TEMST harmonic changes a lot with applied magnetic field, while the second one remains almost field independent. This unusual feature is convenient for magnetic sensing similar to that enabled by Lorentz force magnetometers. The magnetic field detection in the TEMST device is facilitated by the audio sensing system.

Here’s a link to and a citation for the paper,

Thermo-electromagnetic sound transducer based on carbon nanotube sheet by Mikhail Kozlov and Jiyoung Oh. J. Appl. Phys. 116, 094301 (2014); http://dx.doi.org/10.1063/1.4894143 Published online Sept. 2, 2014

This paper is behind a paywall.

OCSiAL (carbon nanotubes) makes moves: a production plant, maybe, in Israel and an international network

OCSiAl, the world’s largest nanotechnology business or developer of the revolutionary material TUBALL depending on the way the wind is blowing, has indicated interest in building a carbon nanotube production facility in Israel according to a Nov. 11, 2014 news item on the Economic Times (of India) website,

Nanotechnology company OCSiAl said on Tuesday [Nov. 11, 2014] it was in advanced talks to establish a production facility in southern Israel at an investment of $30 million.

OCSiAl said it intends to employ around 30 workers in Israel, mainly chemical engineers, industrial engineers, process engineers and automatic machine operators. It has started examining possible sites for the plant.

A Nov. 11, 2014 Time of Israel news article by David Shamah has more details,

The world’s biggest nanotechnology production company, OCSiAl, is shopping around in southern Israel for a site to build what could be the world’s largest nanotube production facility. It will produce as much as 50 tons of Single Wall Carbon Nanotubes (SWCNTs) a year – making it “possibly the largest producer of such nanotubes in the world,” the company announced Tuesday [Nov. 11, 2014].

….

… OCSiAl, … is the world’s biggest maker of the tiny SWCNTs. OCSiAl is an international nanotechnology company with operations in the US, UK, Germany, South Korea and Russia, headquartered in Luxembourg. The company employs 160 workers and is expected to hire 30 people for its Negev plant.

“Israel is one of the world’s leading knowledge and innovation centers in nanotechnology, and this is why we are interested in setting up a plant here,” said Konstantin Notman, vice president of OCSiAl. “We intend to deepen the contact with the Israeli market in all aspects – setting up our largest production facility here, enlarging our customer base, establishing contacts with Israeli dealers, and conducting cooperation with industrial companies and academic bodies.”

OCSiAL has a Nov. 13, 2014 news release, which despite the date seems to have inspired this news item about a SWCNT production plant in Israel.

There is this video produced by OCSiAL showing off some of its current production facilities,

On other fronts, OCSiAL has announced a worldwide partnership network program in a Nov. 12, 2014 news item on Azonano,

OCSiAl, developer of the revolutionary material TUBALL, is now focused on creating a worldwide partnership network. Facing a growing worldwide demand for new materials and solutions on one side, and a great interest of industrial manufacturers in providing these solutions without major changes in their business models and production processes on the other, OCSiAl presented TUBALL as an answer to these demands six months ago and now launches a partnership program.

An OCSiAL Nov. 14, 2014 news release, which despite the date seems to have originated the news item, provides more details,

TUBALL, first introduced in London this past spring, has gained attention of major brands in several industries since then. Not only due to its high “as produced” purity (75%+ of SWCNTs), but also because of its market price, which is 50 times lower than of other products with similar properties. That has been achieved by OCSiAl’s technology, which allows cost-efficient SWСNT synthesis in sufficient volumes and doesn’t require any further enrichment procedures.

To demonstrate TUBALL’s capabilities and to increase the number of its applications, OCSiAl has developed and licensed production technology for several TUBALL-based industrial modifiers: for cathodes of Li-ion batteries (TUBALL BATT), rubbers and tires (TUBALL RUBBER), thermoplastics (TUBALL PLAST), thermoset composites (TUBALL COMP) and for transparent conductive films (TUBALL INK). Modifiers for aluminium, concrete, paints and some other materials are under development.

The partnership program is compatible with various business models and works perfectly for different types of companies, including:

  • product manufacturers, who can produce TUBALL-enhanced versions of their current products;
  • solution providers, who can start their own production of TUBALL-based industrial modifiers (masterbatches and suspensions) using OCSiAl’s licensed technology for their own business, or to satisfy the demands of their clients;
  • large-scale distributors, who can introduce TUBALL and TUBALL-based modifiers to their local markets.

“We have great expectations for further prosperity of our business in cooperation with OCSiAl”, – says Managing Director of Evermore company Wu Lu-Hao. “We hope not only to attract new clients via highly sought TUBALL product, but to advance existing partnerships through offering new opportunities for development of our client’s products”

TUBALL’s introduction to the nanomaterials market served as a pivot point for many industries, which previously experienced difficulties with the industrial usage of nanomodifiers, due to their high cost and absence of an efficient synthesis technology, and the lack of any alternative solutions.

Now further development of a worldwide partnership network will remove the last geographical, technological and economical borders, empowering new wave of revolution in materials manufacture.

“Analytical studies suggest that the nanomaterials market will experience rapid growth in the next five to ten years, — says Yuri Koropachinskiy, OCSiAl’s President and co-founder — If you want to be there in 2025 — now is the time to start.”

You can find out more OCSiAl on its website; I last wrote about the company in a Sept. 11, 2014 posting.

India, Lockheed Martin, and canal-top solar power plants

Apparently the state of Gujarat (India) has inspired at least one other state, Punjab, to build (they hope) a network of photovoltaic (solar energy) plants over top of their canal system (from a Nov. 16, 2014 article by Mridul Chadha for cleantechnica.com),

India’s northern state of Punjab plans to set up 1,000 MW of solar PV projects to cover several kilometres of canals over the next three years. The state government has announced a target to cover 5,000 km of canals across the state. Through this program, the government hopes to generate 15% of the state’s total electricity demand.

Understandably, the construction of canal-top power plants is technically and structurally very different from rooftop or ground-based solar PV projects. The mounting structures for the solar PV modules cannot be heavy, as it could adversely impact the structural integrity of the canal itself. The structures should be easy to work with, as they are to be set up over a slope.

This is where the Punjab government has asked Lockheed Martin for help. The US-based company has entered into an agreement with the Punjab government to develop lightweight mounting structures for solar panels using nanotechnology.

Canal and rooftop solar power projects are the only viable options for Punjab as it is an agricultural state and land availability for large-scale ground-mounted projects remains an issue. As a result, the state government has a relatively lower (compared to other states) capacity addition target of 2 GW.

There’s more about the Punjab and current plans to increase its investment in solar photovoltaics in the article.

Here’s an image of a canal-top solar plant near Kadi (Gujarat),

Canal_Top_Solar_Power_PlantImage Credit: Hitesh vip | CC BY-SA 3.0

A Nov. 15, 2014 news item by Kamya Kandhar for efytimes.com provides a few more details about this Memorandum of Understanding (MOU),

Punjab government had announced its tie up with U.S. aerospace giant Lockheed Martin to expand the solar power generation and overcome power problems in the State. As per the agreement, the state will put in 1,000 MW solar power within the next three years. Lockheed Martin has agreed to provide plastic structures for solar panels on canals by using nano technology.

While commenting upon the agreement, a spokesperson said, “The company would also provide state-of-the-art technology to convert paddy straw into energy, solving the lingering problem of paddy straw burning in the state. The Punjab government and Lockheed Martin would ink a MoU in this regard [on Friday, Nov. 14, 2014].”

The decision was taken during a meeting between three-member team from Lockheed Martin, involving the CEO Phil Shaw, Chief Innovation Officer Tushar Shah and Regional Director Jagmohan Singh along with Punjab Non-Conventional Energy Minister Bikram Singh Majithia and other senior Punjab officials.

As for paddy straw and its conversion into energy, there’s this from a Nov. 14, 2014 news item on India West.com,

Shaw [CEO Phil Shaw] said Lockheed has come out with waste-to-energy conversion solutions with successful conversion of waste products to electricity, heat and fuel by using gasification processes. He said it was an environmentally friendly green recycling technology, which requires little space and the plants are fully automated.

Getting back to the nanotechnology, I was not able to track down any information about nanotechnology-enabled plastics and Lockheed Martin. But, there is a Dec. 11, 2013 interview with Travis Earles, Lockheed Martin Advanced materials and nanotechnology innovation executive and policy leader, written up by Kris Walker for Azonano. Note: this is a general interview and focuses largely on applications for carbon nanotubes and graphene.

Super-capacitors on automobiles

Queensland University of Technology* (QUT; Australia) researchers are hopeful they can adapt supercapacitors in the form of a fine film tor use in electric vehicles making them more energy-efficient. From a Nov. 6, 2014 news item on ScienceDaily,

A car powered by its own body panels could soon be driving on our roads after a breakthrough in nanotechnology research by a QUT team.

Researchers have developed lightweight “supercapacitors” that can be combined with regular batteries to dramatically boost the power of an electric car.

The discovery was made by Postdoctoral Research Fellow Dr Jinzhang Liu, Professor Nunzio Motta and PhD researcher Marco Notarianni, from QUT’s Science and Engineering Faculty — Institute for Future Environments, and PhD researcher Francesca Mirri and Professor Matteo Pasquali, from Rice University in Houston, in the United States.

A Nov. 6, 2014 QUT news release, which originated the news item, describes supercapacitors, the research, and the need for this research in more detail,

The supercapacitors – a “sandwich” of electrolyte between two all-carbon electrodes – were made into a thin and extremely strong film with a high power density.

The film could be embedded in a car’s body panels, roof, doors, bonnet and floor – storing enough energy to turbocharge an electric car’s battery in just a few minutes.

“Vehicles need an extra energy spurt for acceleration, and this is where supercapacitors come in. They hold a limited amount of charge, but they are able to deliver it very quickly, making them the perfect complement to mass-storage batteries,” he said.

“Supercapacitors offer a high power output in a short time, meaning a faster acceleration rate of the car and a charging time of just a few minutes, compared to several hours for a standard electric car battery.”

Dr Liu said currently the “energy density” of a supercapacitor is lower than a standard lithium ion (Li-Ion) battery, but its “high power density”, or ability to release power in a short time, is “far beyond” a conventional battery.

“Supercapacitors are presently combined with standard Li-Ion batteries to power electric cars, with a substantial weight reduction and increase in performance,” he said.

“In the future, it is hoped the supercapacitor will be developed to store more energy than a Li-Ion battery while retaining the ability to release its energy up to 10 times faster – meaning the car could be entirely powered by the supercapacitors in its body panels.

“After one full charge this car should be able to run up to 500km – similar to a petrol-powered car and more than double the current limit of an electric car.”

Dr Liu said the technology would also potentially be used for rapid charges of other battery-powered devices.

“For example, by putting the film on the back of a smart phone to charge it extremely quickly,” he said.

The discovery may be a game-changer for the automotive industry, with significant impacts on financial, as well as environmental, factors.

“We are using cheap carbon materials to make supercapacitors and the price of industry scale production will be low,” Professor Motta said.

“The price of Li-Ion batteries cannot decrease a lot because the price of Lithium remains high. This technique does not rely on metals and other toxic materials either, so it is environmentally friendly if it needs to be disposed of.”

A Nov. 10, 2014 news item on Azonano describes the Rice University (Texas, US) contribution to this work,

Rice University scientist Matteo Pasquali and his team contributed to two new papers that suggest the nano-infused body of a car may someday power the car itself.

Rice supplied high-performance carbon nanotube films and input on the device design to scientists at the Queensland University of Technology in Australia for the creation of lightweight films containing supercapacitors that charge quickly and store energy. The inventors hope to use the films as part of composite car doors, fenders, roofs and other body panels to significantly boost the power of electric vehicles.

A Nov. 7, 2014 Rice University news release, which originated the news item, offers a few technical details about the film being proposed for use as a supercapacitor on car panels,

Researchers in the Queensland lab of scientist Nunzio Motta combined exfoliated graphene and entangled multiwalled carbon nanotubes combined with plastic, paper and a gelled electrolyte to produce the flexible, solid-state supercapacitors.

“Nunzio’s team is making important advances in the energy-storage area, and we were glad to see that our carbon nanotube film technology was able to provide breakthrough current collection capability to further improve their devices,” said Pasquali, a Rice professor of chemical and biomolecular engineering and chemistry. “This nice collaboration is definitely bottom-up, as one of Nunzio’s Ph.D. students, Marco Notarianni, spent a year in our lab during his Master of Science research period a few years ago.”

“We built on our earlier work on CNT films published in ACS Nano, where we developed a solution-based technique to produce carbon nanotube films for transparent electrodes in displays,” said Francesca Mirri, a graduate student in Pasquali’s research group and co-author of the papers. “Now we see that carbon nanotube films produced by the solution-processing method can be applied in several areas.”

As currently designed, the supercapacitors can be charged through regenerative braking and are intended to work alongside the lithium-ion batteries in electric vehicles, said co-author Notarianni, a Queensland graduate student.

“Vehicles need an extra energy spurt for acceleration, and this is where supercapacitors come in. They hold a limited amount of charge, but with their high power density, deliver it very quickly, making them the perfect complement to mass-storage batteries,” he said.

Because hundreds of film supercapacitors are used in the panel, the electric energy required to power the car’s battery can be stored in the car body. “Supercapacitors offer a high power output in a short time, meaning a faster acceleration rate of the car and a charging time of just a few minutes, compared with several hours for a standard electric car battery,” Notarianni said.

The researchers foresee such panels will eventually replace standard lithium-ion batteries. “In the future, it is hoped the supercapacitor will be developed to store more energy than an ionic battery while retaining the ability to release its energy up to 10 times faster – meaning the car would be powered by the supercapacitors in its body panels,” said Queensland postdoctoral researcher Jinzhang Liu.

Here’s an image of graphene infused with carbon nantoubes used in the supercapacitor film,

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Courtesy of Nunzio Motta/Queensland University of Technology - See more at: http://news.rice.edu/2014/11/07/supercharged-panels-may-power-cars/#sthash.0RPsIbMY.dpuf

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Courtesy of Nunzio Motta/Queensland University of Technology

Here are links to and citations for the two papers published by the researchers,

Graphene-based supercapacitor with carbon nanotube film as highly efficient current collector by Marco Notarianni, Jinzhang Liu, Francesca Mirri, Matteo Pasquali, and Nunzio Motta. Nanotechnology Volume 25 Number 43 doi:10.1088/0957-4484/25/43/435405

High performance all-carbon thin film supercapacitors by Jinzhang Liu, Francesca Mirri, Marco Notarianni, Matteo Pasquali, and Nunzio Motta. Journal of Power Sources Volume 274, 15 January 2015, Pages 823–830 DOI: 10.1016/j.jpowsour.2014.10.104

Both articles are behind paywalls.

One final note, Dexter Johnson provides some insight into issues with graphene-based supercapacitors and what makes this proposed application attractive in his Nov. 7, 2014 post on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website; Note: Links have been removed),

The hope has been that someone could make graphene electrodes for supercapacitors that would boost their energy density into the range of chemical-based batteries. The supercapacitors currently on the market have on average an energy density around 28 Wh/kg, whereas a Li-ion battery holds about 200Wh/kg. That’s a big gap to fill.

The research in the field thus far has indicated that graphene’s achievable surface area in real devices—the factor that determines how many ions a supercapacitor electrode can store, and therefore its energy density—is not any better than traditional activated carbon. In fact, it may not be much better than a used cigarette butt.

Though graphene may not help increase supercapacitors’ energy density, its usefulness in this application may lie in the fact that its natural high conductivity will allow superconductors to operate at higher frequencies than those that are currently on the market. Another likely benefit that graphene will yield comes from the fact that it can be structured and scaled down, unlike other supercapacitor materials.

I recommend reading Dexter’s commentary in its entirety.

*’University of Queensland’ corrected to “Queensland University of Technology’ on Nov. 10, 2014 at 1335 PST.

Bomb-sniffing and other sniffing possibilities from Utah (US state)

A Nov. 4, 2014 news item on Phys.org features some research in Utah on the use of carbon nanotubes for sensing devices,

University of Utah engineers have developed a new type of carbon nanotube material for handheld sensors that will be quicker and better at sniffing out explosives, deadly gases and illegal drugs.

A carbon nanotube is a cylindrical material that is a hexagonal or six-sided array of carbon atoms rolled up into a tube. Carbon nanotubes are known for their strength and high electrical conductivity and are used in products from baseball bats and other sports equipment to lithium-ion batteries and touchscreen computer displays.

Vaporsens, a university spin-off company, plans to build a prototype handheld sensor by year’s end and produce the first commercial scanners early next year, says co-founder Ling Zang, a professor of materials science and engineering and senior author of a study of the technology published online Nov. 4 [2014] in the journal Advanced Materials.

The new kind of nanotubes also could lead to flexible solar panels that can be rolled up and stored or even “painted” on clothing such as a jacket, he adds.

Here’s Ling Zang holding a prototype of the device,

Ling Zang, a University of Utah professor of materials science and engineering, holds a prototype detector that uses a new type of carbon nanotube material for use in handheld scanners to detect explosives, toxic chemicals and illegal drugs. Zang and colleagues developed the new material, which will make such scanners quicker and more sensitive than today’s standard detection devices. Ling’s spinoff company, Vaporsens, plans to produce commercial versions of the new kind of scanner early next year. Courtesy: University of Utah

Ling Zang, a University of Utah professor of materials science and engineering, holds a prototype detector that uses a new type of carbon nanotube material for use in handheld scanners to detect explosives, toxic chemicals and illegal drugs. Zang and colleagues developed the new material, which will make such scanners quicker and more sensitive than today’s standard detection devices. Ling’s spinoff company, Vaporsens, plans to produce commercial versions of the new kind of scanner early next year. Courtesy: University of Utah

A Nov. 4, 2014 University of Utah news release (also on EurekAlert), which originated the news item, provides more detail about the research,

Zang and his team found a way to break up bundles of the carbon nanotubes with a polymer and then deposit a microscopic amount on electrodes in a prototype handheld scanner that can detect toxic gases such as sarin or chlorine, or explosives such as TNT.

When the sensor detects molecules from an explosive, deadly gas or drugs such as methamphetamine, they alter the electrical current through the nanotube materials, signaling the presence of any of those substances, Zang says.

“You can apply voltage between the electrodes and monitor the current through the nanotube,” says Zang, a professor with USTAR, the Utah Science Technology and Research economic development initiative. “If you have explosives or toxic chemicals caught by the nanotube, you will see an increase or decrease in the current.”

By modifying the surface of the nanotubes with a polymer, the material can be tuned to detect any of more than a dozen explosives, including homemade bombs, and about two-dozen different toxic gases, says Zang. The technology also can be applied to existing detectors or airport scanners used to sense explosives or chemical threats.

Zang says scanners with the new technology “could be used by the military, police, first responders and private industry focused on public safety.”

Unlike the today’s detectors, which analyze the spectra of ionized molecules of explosives and chemicals, the Utah carbon-nanotube technology has four advantages:

• It is more sensitive because all the carbon atoms in the nanotube are exposed to air, “so every part is susceptible to whatever it is detecting,” says study co-author Ben Bunes, a doctoral student in materials science and engineering.

• It is more accurate and generates fewer false positives, according to lab tests.

• It has a faster response time. While current detectors might find an explosive or gas in minutes, this type of device could do it in seconds, the tests showed.

• It is cost-effective because the total amount of the material used is microscopic.

This study was funded by the Department of Homeland Security, Department of Defense, National Science Foundation and NASA. …

Here’s a link to and a citation for the research paper,

Photodoping and Enhanced Visible Light Absorption in Single-Walled Carbon Nanotubes Functionalized with a Wide Band Gap Oligomer by Benjamin R. Bunes, Miao Xu, Yaqiong Zhang, Dustin E. Gross, Avishek Saha, Daniel L. Jacobs, Xiaomei Yang, Jeffrey S. Moore, and Ling Zang. Advanced Materials DOI: 10.1002/adma.201404112 Article first published online: 4 NOV 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

For anyone curious about Vaporsens, you can find more here.