Monthly Archives: December 2015

A bioelectronic future made possible with DNA-based electromechanical switch

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DNA-based electronics are discussed in the context of a Dec. 14, 2015 news item by Beth Ellison for Azonano about research into electromechanical switches at the University of California at Davis,

Researchers from the University of California, Davis (UC Davis) and the University of Washington have shown the possibility of using DNA-based electromechanical switches for nanoscale computing.

DNA is considered to be the molecule of life, and researchers have shown considerable interest in utilizing DNA as a nanoscale material in various applications.

A Dec. 14, 2015 UC Davis news release on EurekAlert, which originated the news item, provides more detail,

In their paper published in Nature Communications, the team demonstrated that changing the structure of the DNA double helix by modifying its environment allows the conductance (the ease with which an electric current passes) to be reversibly controlled. This ability to structurally modulate the charge transport properties may enable the design of unique nanodevices based on DNA. These devices would operate using a completely different paradigm than today’s conventional electronics.

“As electronics get smaller they are becoming more difficult and expensive to manufacture, but DNA-based devices could be designed from the bottom-up using directed self-assembly techniques such as ‘DNA origami’,” said Josh Hihath, assistant professor of electrical and computer engineering at UC Davis and senior author on the paper. DNA origami is the folding of DNA to create two- and three-dimensional shapes at the nanoscale level.

“Considerable progress has been made in understanding DNA’s mechanical, structural, and self-assembly properties and the use of these properties to design structures at the nanoscale. The electrical properties, however, have generally been difficult to control,” said Hihath.

New Twist on DNA? Possible Paradigms for Computing

In addition to potential advantages in fabrication at the nanoscale level, such DNA-based devices may also improve the energy efficiency of electronic circuits. The size of devices has been significantly reduced over the last 40 years, but as the size has decreased, the power density on-chip has increased. Scientists and engineers have been exploring novel solutions to improve the efficiency.

“There’s no reason that computation must be done with traditional transistors. Early computers were fully mechanical and later worked on relays and vacuum tubes,” said Hihath. “Moving to an electromechanical platform may eventually allow us to improve the energy efficiency of electronic devices at the nanoscale.”

This work demonstrates that DNA is capable of operating as an electromechanical switch and could lead to new paradigms for computing.

To develop DNA into a reversible switch, the scientists focused on switching between two stable conformations of DNA, known as the A-form and the B-form. In DNA, the B-form is the conventional DNA duplex that is commonly associated with these molecules. The A-form is a more compact version with different spacing and tilting between the base pairs. Exposure to ethanol forces the DNA into the A-form conformation resulting in an increased conductance. Similarly, by removing the ethanol, the DNA can switch back to the B-form and return to its original reduced conductance value.

One Step Toward Molecular Computing

In order to develop this finding into a technologically viable platform for electronics, the authors also noted that there is still a great deal of work to be done. Although this discovery provides a proof-of-principle demonstration of electromechanical switching in DNA, there are generally two major hurdles yet to be overcome in the field of molecular electronics. First, billions of active molecular devices must be integrated into the same circuit as is done currently in conventional electronics. Next, scientists must be able to gate specific devices individually in such a large system.

“Eventually, the environmental gating aspect of this work will have to be replaced with a mechanical or electrical signal in order to locally address a single device,” noted Hihath.

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

Conformational gating of DNA conductance by Juan Manuel Artés, Yuanhui Li, Jianqing Qi, M. P. Anantram, & Joshua Hihath. Nature Communications 6, Article number: 8870 doi:10.1038/ncomms9870 Published 09 December 2015

This paper is open access.

Ceramic firefighting foam: better at extinguishing fires and nontoxic

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A Dec. 14, 2015 news item on Nanowerk announces a new ceramic firefighting foam developed in Russia,

A team of chemists from ITMO University, in collaboration with research company SOPOT, has developed a novel type of firefighting foam based on inorganic silica nanoparticles. The new foam beats existing analogues in fire extinguishing capacity, thermal and mechanical stability and biocompatibility.

A Dec. 14, 2015 ITMO University press release on EurekAlert, which originated the news item, provides more details,

Fighting large-scale fires usually involves firefighting foams based on synthetic substances, such as prefluorinated surfactants, that, despite their effectiveness, are extremely toxic for living organisms. Complete biodegradation of such foams can last for more than 200 years [emphasis mine], with residues quickly penetrating deep into soil and surface water. This leads to the the accumulation of toxic elements in living organisms, such as plants, animals and men. Many countries have declined the use of such fire extinguishing agents or opted for reducing the production of such substances despite the absence of any decent alternatives.

A group of scientists from the International Laboratory of Advanced Materials and Technologies (SCAMT) at ITMO University in Saint Petersburg and research company SOPOT devised a foam, which was awarded full biodegradability and whose fire extinguishing capacity is higher than that of any existing analogue currently in use by fire fighters. After the fire is extinguished, the substance actively absorbs water, softens and falls apart into bioinert silica particles. And even when the foam accidentally enters living organisms, it does not not pose any danger to them.

“Our foam is based on silica nanoparticles, which create a polymer network when exposed to air,” says Alexander Vinogradov, deputy head of the SCAMT laboratory. “Such a network embraces and adheres to the burning object and momentarily cools it down. At the same time, the foam itself hardens. The inorganic origin of this polymer network allows it to resist temperatures above 1000 degrees Celsius, which ensures gigantic stability from the aggressive environment in the midst of a raging fire.”

“Most existing foams are made of organic materials and quickly deteriorate when temperature approaches 300 degrees Celsius. In our case, the foam creates a hard frame that not only puts out the fire, but also protects the object from re-ignition. With ordinary foams, re-ignition occurs within seconds after flame is applied to the object again.”

The scientists conducted a series of large-scale experiments of the hardening foam, including the imitation of an actual forest fire. The foam was used to create a flame retardant belt that was supposed stop the spread of the fire. The tests demonstrated that the foam easily localizes the forest fire seat and can stay active during the whole fire season.

“The flame retardant belt made of our foam will prevent the spread of any forest fire, regardless of its strength and level of complexity,” says Gennady Kuprin, head of SOPOT. “We can localize the fire and be sure that the adjacent territories will be safe. This is crucial to organize evacuation works during forest fires, where 9 of 10 people die in our and other countries.”

The standard firefighting foam can take up to 200 years before completely degrading? I hope this new foam is all they say it is and that they can get it to market. In the meantime, here’s a link to and a citation for the researchers’ paper,

Silica foams for fire prevention and firefighting by Alexander V. Vinogradov, Denis Kuprin, Iosif Abduragimov, Gennadii Kuprin, Evgeniy Serebriyakov, and Vladimir V. Vinogradov. ACS Appl. Mater. Interfaces, DOI: 10.1021/acsami.5b08653
Publication Date (Web): October 22, 2015

Copyright © 2015 American Chemical Society

This is paper is behind a paywall. But, the researchers have made an image of the foam available,

Caption: This is an electronic microscope image of hybrid silica foam. Credit: ITMO University

Caption: This is an electronic microscope image of hybrid silica foam. Credit: ITMO University

For anyone curious about SOPOT, here’s more from the company’s About page,

  “NPO Sopot” was founded in 1994 in St. Petersburg. Its creation was preceded by many years of scientific research and experimental design work done in person at the head of the firm basis of the Ministry of Defence and the Ministry of Internal Affairs of Russia, as well as, with the participation and cooperation with representatives of several institutions of the defense industry (the Sukhoi Design Bureau, Institute TRANSMASH, Academy. Zhukovsky etc.), the Ministry of Civil aviation, Fire Prevention Russian Interior Ministry, the Russian Interior Ministry VIPTSH

General Director of JSC “NPO” Sopot “Gennady Kuprin. Winner of the National Industry Award” Bison-2006 “, the grand prize Emergencies Ministry in 2005 and 2006., Awarded the” Golden Shield of the Russian economy, “international diploma” European quality “member of the International Academy of Patronage, the World Academy of Integrated Security.

…

Wearable tech for Christmas 2015 and into 2016

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This is a roundup post of four items to cross my path this morning (Dec. 17, 2015), all of them concerned with wearable technology.

The first, a Dec. 16, 2015 news item on phys.org, is a fluffy little piece concerning the imminent arrival of a new generation of wearable technology,

It’s not every day that there’s a news story about socks. But in November [2015], a pair won the Best New Wearable Technology Device Award at a Silicon Valley conference. The smart socks, which track foot landings and cadence, are at the forefront of a new generation of wearable electronics, according to an article in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society [ACS].

That news item was originated by a Dec. 16, 2015 ACS news release on EurekAlert which adds this,

Marc S. Reisch, a senior correspondent at C&EN, notes that stiff wristbands like the popular FitBit that measure heart rate and the number of steps people take have become common. But the long-touted technology needed to create more flexible monitoring devices has finally reached the market. Developers have successfully figured out how to incorporate stretchable wiring and conductive inks in clothing fabric, program them to transmit data wirelessly and withstand washing.

In addition to smart socks, fitness shirts and shoe insoles are on the market already or are nearly there. Although athletes are among the first to gain from the technology, the less fitness-oriented among us could also benefit. One fabric concept product — designed not for covering humans but a car steering-wheel — could sense driver alertness and make roads safer.

Reisch’s Dec. 7, 2015 article (C&EN vol. 93, issue 48, pp. 28-90) provides more detailed information and market information such as this,

Materials suppliers, component makers, and apparel developers gathered at a printed-electronics conference in Santa Clara, Calif., within a short drive of tech giants such as Google and Apple, to compare notes on embedding electronics into the routines of daily life. A notable theme was the effort to stealthily [emphasis mine] place sensors on exercise shirts, socks, and shoe soles so that athletes and fitness buffs can wirelessly track their workouts and doctors can monitor the health of their patients.

“Wearable technology is becoming more wearable,” said Raghu Das, chief executive officer of IDTechEx [emphasis mine], the consulting firm that organized the conference. By that he meant the trend is toward thinner and more flexible devices that include not just wrist-worn fitness bands but also textiles printed with stretchable wiring and electronic sensors, thanks to advances in conductive inks.

Interesting use of the word ‘stealthy’, which often suggests something sneaky as opposed to merely secretive. I imagine what’s being suggested is that the technology will not impose itself on the user (i.e., you won’t have to learn how to use it as you did with phones and computers).

Leading into my second item, IDC (International Data Corporation), not to be confused with IDTechEx, is mentioned in a Dec. 17, 2015 news item about wearable technology markets on phys.org,

The global market for wearable technology is seeing a surge, led by watches, smart clothing and other connected gadgets, a research report said Thursday [Dec. 16, 2015].

IDC said its forecast showed the worldwide wearable device market will reach a total of 111.1 million units in 2016, up 44.4 percent from this year.

By 2019, IDC sees some 214.6 million units, or a growth rate averaging 28 percent.

A Dec. 17, 2015 IDC press release, which originated the news item, provides more details about the market forecast,

“The most common type of wearables today are fairly basic, like fitness trackers, but over the next few years we expect a proliferation of form factors and device types,” said Jitesh Ubrani , Senior Research Analyst for IDC Mobile Device Trackers. “Smarter clothing, eyewear, and even hearables (ear-worn devices) are all in their early stages of mass adoption. Though at present these may not be significantly smarter than their analog counterparts, the next generation of wearables are on track to offer vastly improved experiences and perhaps even augment human abilities.”

One of the most popular types of wearables will be smartwatches, reaching a total of 34.3 million units shipped in 2016, up from the 21.3 million units expected to ship in 2015. By 2019, the final year of the forecast, total shipments will reach 88.3 million units, resulting in a five-year CAGR of 42.8%.

“In a short amount of time, smartwatches have evolved from being extensions of the smartphone to wearable computers capable of communications, notifications, applications, and numerous other functionalities,” noted Ramon Llamas , Research Manager for IDC’s Wearables team. “The smartwatch we have today will look nothing like the smartwatch we will see in the future. Cellular connectivity, health sensors, not to mention the explosive third-party application market all stand to change the game and will raise both the appeal and value of the market going forward.

“Smartwatch platforms will lead the evolution,” added Llamas. “As the brains of the smartwatch, platforms manage all the tasks and processes, not the least of which are interacting with the user, running all of the applications, and connecting with the smartphone. Once that third element is replaced with cellular connectivity, the first two elements will take on greater roles to make sense of all the data and connections.”

Top Five Smartwatch Platform Highlights

Apple’s watchOS will lead the smartwatch market throughout our forecast, with a loyal fanbase of Apple product owners and a rapidly growing application selection, including both native apps and Watch-designed apps. Very quickly, watchOS has become the measuring stick against which other smartwatches and platforms are compared. While there is much room for improvement and additional features, there is enough momentum to keep it ahead of the rest of the market.

Android/Android Wear will be a distant second behind watchOS even as its vendor list grows to include technology companies (ASUS, Huawei, LG, Motorola, and Sony) and traditional watchmakers (Fossil and Tag Heuer). The user experience on Android Wear devices has been largely the same from one device to the next, leaving little room for OEMs to develop further and users left to select solely on price and smartwatch design.

Smartwatch pioneer Pebble will cede market share to AndroidWear and watchOS but will not disappear altogether. Its simple user interface and devices make for an easy-to-understand use case, and its price point relative to other platforms makes Pebble one of the most affordable smartwatches on the market.

Samsung’s Tizen stands to be the dark horse of the smartwatch market and poses a threat to Android Wear, including compatibility with most flagship Android smartphones and an application selection rivaling Android Wear. Moreover, with Samsung, Tizen has benefited from technology developments including a QWERTY keyboard on a smartwatch screen, cellular connectivity, and new user interfaces. It’s a combination that helps Tizen stand out, but not enough to keep up with AndroidWear and watchOS.

There will be a small, but nonetheless significant market for smart wristwear running on a Real-Time Operating System (RTOS), which is capable of running third-party applications, but not on any of these listed platforms. These tend to be proprietary operating systems and OEMs will use them when they want to champion their own devices. These will help within specific markets or devices, but will not overtake the majority of the market.

The company has provided a table with five-year CAGR (compound annual growth rate) growth estimates, which can be found with the Dec. 17, 2015 IDC press release.

Disclaimer: I am not endorsing IDC’s claims regarding the market for wearable technology.

For the third and fourth items, it’s back to the science. A Dec. 17, 2015 news item on Nanowerk, describes, in general terms, some recent wearable technology research at the University of Manchester (UK), Note: A link has been removed),

Cheap, flexible, wireless graphene communication devices such as mobile phones and healthcare monitors can be directly printed into clothing and even skin, University of Manchester academics have demonstrated.

In a breakthrough paper in Scientific Reports (“Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications”), the researchers show how graphene could be crucial to wearable electronic applications because it is highly-conductive and ultra-flexible.

The research could pave the way for smart, battery-free healthcare and fitness monitoring, phones, internet-ready devices and chargers to be incorporated into clothing and ‘smart skin’ applications – printed graphene sensors integrated with other 2D materials stuck onto a patient’s skin to monitor temperature, strain and moisture levels.

Detail is provided in a Dec. 17, 2015 University of Manchester press release, which originated the news item, (Note: Links have been removed),

Examples of communication devices include:

• In a hospital, a patient wears a printed graphene RFID tag on his or her arm. The tag, integrated with other 2D materials, can sense the patient’s body temperature and heartbeat and sends them back to the reader. The medical staff can monitor the patient’s conditions wirelessly, greatly simplifying the patient’s care.

• In a care home, battery-free printed graphene sensors can be printed on elderly peoples’ clothes. These sensors could detect and collect elderly people’s health conditions and send them back to the monitoring access points when they are interrogated, enabling remote healthcare and improving quality of life.

Existing materials used in wearable devices are either too expensive, such as silver nanoparticles, or not adequately conductive to have an effect, such as conductive polymers.

Graphene, the world’s thinnest, strongest and most conductive material, is perfect for the wearables market because of its broad range of superlative qualities. Graphene conductive ink can be cheaply mass produced and printed onto various materials, including clothing and paper.

“Sir Kostya Novoselov

To see evidence that cheap, scalable wearable communication devices are on the horizon is excellent news for graphene commercial applications.

Sir Kostya Novoselov (tweet)„

The researchers, led by Dr Zhirun Hu, printed graphene to construct transmission lines and antennas and experimented with these in communication devices, such as mobile and Wifi connectivity.

Using a mannequin, they attached graphene-enabled antennas on each arm. The devices were able to ‘talk’ to each other, effectively creating an on-body communications system.

The results proved that graphene enabled components have the required quality and functionality for wireless wearable devices.

Dr Hu, from the School of Electrical and Electronic Engineering, said: “This is a significant step forward – we can expect to see a truly all graphene enabled wireless wearable communications system in the near future.

“The potential applications for this research are huge – whether it be for health monitoring, mobile communications or applications attached to skin for monitoring or messaging.

“This work demonstrates that this revolutionary scientific material is bringing a real change into our daily lives.”

Co-author Sir Kostya Novoselov, who with his colleague Sir Andre Geim first isolated graphene at the University in 2004, added: “Research into graphene has thrown up significant potential applications, but to see evidence that cheap, scalable wearable communication devices are on the horizon is excellent news for graphene commercial applications.”

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

Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications by Xianjun Huang, Ting Leng, Mengjian Zhu, Xiao Zhang, JiaCing Chen, KuoHsin Chang, Mohammed Aqeeli, Andre K. Geim, Kostya S. Novoselov, & Zhirun Hu. Scientific Reports 5, Article number: 18298 (2015) doi:10.1038/srep18298 Published online: 17 December 2015

This is an open access paper.

The next and final item concerns supercapacitors for wearable tech, which makes it slightly different from the other items and is why, despite the date, this is the final item. The research comes from Case Western Research University (CWRU; US) according to a Dec. 16, 2015 news item on Nanowerk (Note: A link has been removed),

Wearable power sources for wearable electronics are limited by the size of garments.

With that in mind, researchers at Case Western Reserve University have developed flexible wire-shaped microsupercapacitors that can be woven into a jacket, shirt or dress (Energy Storage Materials, “Flexible and wearable wire-shaped microsupercapacitors based on highly aligned titania and carbon nanotubes”).

A Dec. 16, 2015 CWRU news release (on EurekAlert), which originated the news item, provides more detail about a device that would make wearable tech more wearable (after all, you don’t want to recharge your clothes the same way you do your phone and other mobile devices),

By their design or by connecting the capacitors in series or parallel, the devices can be tailored to match the charge storage and delivery needs of electronics donned.

While there’s been progress in development of those electronics–body cameras, smart glasses, sensors that monitor health, activity trackers and more–one challenge remaining is providing less obtrusive and cumbersome power sources.

“The area of clothing is fixed, so to generate the power density needed in a small area, we grew radially-aligned titanium oxide nanotubes on a titanium wire used as the main electrode,” said Liming Dai, the Kent Hale Smith Professor of Macromolecular Science and Engineering. “By increasing the surface area of the electrode, you increase the capacitance.”

Dai and Tao Chen, a postdoctoral fellow in molecular science and engineering at Case Western Reserve, published their research on the microsupercapacitor in the journal Energy Storage Materials this week. The study builds on earlier carbon-based supercapacitors.

A capacitor is cousin to the battery, but offers the advantage of charging and releasing energy much faster.

How it works

In this new supercapacitor, the modified titanium wire is coated with a solid electrolyte made of polyvinyl alcohol and phosphoric acid. The wire is then wrapped with either yarn or a sheet made of aligned carbon nanotubes, which serves as the second electrode. The titanium oxide nanotubes, which are semiconducting, separate the two active portions of the electrodes, preventing a short circuit.

In testing, capacitance–the capability to store charge–increased from 0.57 to 0.9 to 1.04 milliFarads per micrometer as the strands of carbon nanotube yarn were increased from 1 to 2 to 3.

When wrapped with a sheet of carbon nanotubes, which increases the effective area of electrode, the microsupercapactitor stored 1.84 milliFarads per micrometer. Energy density was 0.16 x 10-3 milliwatt-hours per cubic centimeter and power density .01 milliwatt per cubic centimeter.

Whether wrapped with yarn or a sheet, the microsupercapacitor retained at least 80 percent of its capacitance after 1,000 charge-discharge cycles. To match various specific power needs of wearable devices, the wire-shaped capacitors can be connected in series or parallel to raise voltage or current, the researchers say.

When bent up to 180 degrees hundreds of times, the capacitors showed no loss of performance. Those wrapped in sheets showed more mechanical strength.

“They’re very flexible, so they can be integrated into fabric or textile materials,” Dai said. “They can be a wearable, flexible power source for wearable electronics and also for self-powered biosensors or other biomedical devices, particularly for applications inside the body.” [emphasis mine]

Dai ‘s lab is in the process of weaving the wire-like capacitors into fabric and integrating them with a wearable device.

So one day we may be carrying supercapacitors in our bodies? I’m not sure how I feel about that goal. In any event, here’s a link and a citation for the paper,

Flexible and wearable wire-shaped microsupercapacitors based on highly aligned titania and carbon nanotubes by Tao Chen, Liming Dai. Energy Storage Materials Volume 2, January 2016, Pages 21–26 doi:10.1016/j.ensm.2015.11.004

This paper appears to be open access.

You gotta shake, shake, shake those nanomaterials out of the water

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A team at Michigan Technological University (Michigan Tech) has developed a simple technique for clearing nanoparticles from water according to a Dec. 10, 2015 news item on Nanotechnology Now,

Nano implies small—and that’s great for use in medical devices, beauty products and smartphones—but it’s also a problem. The tiny nanoparticles, nanowires, nanotubes and other nanomaterials that make up our technology eventually find their way into water. The Environmental Protection Agency says more 1,300 commercial products use some kind of nanomaterial. And we just don’t know the full impact on health and the environment.

A Dec. 10, 2015 Michigan Tech news release, which originated the news item, describes the concept and the research in more detail,

“Look at plastic,” says Yoke Khin Yap, a professor of physics at Michigan Technological University. “These materials changed the world over the past decades—but can we clean up all the plastic in the ocean? We struggle to clean up meter-scale plastics, so what happens when we need to clean on the nano-scale?”

…

The method sounds like a salad dressing recipe: take water, sprinkle in nanomaterials, add oil and shake.

Water and oil don’t mix, of course, but shaking them together is what makes salad dressing so great. Only instead of emulsifying and capturing bits of shitake or basil in tiny olive oil bubbles, this mixture grabs nanomaterials.

Dongyan Zhang, a research professor of physics at Michigan Tech, led the experiments, which covered tests on carbon nanotubes, graphene, boron nitride nanotubes, boron nitride nanosheets and zinc oxide nanowires. Those are used in everything from carbon fiber golf clubs to sunscreen.

“These materials are very, very tiny, and that means if you try to remove them and clean them out of contaminated water, that it’s quite difficult,” Zhang says, adding that techniques like filter paper or meshes often don’t work.

What makes shaking work is the shape of one- and two-dimensional nanomaterials. As the oil and water separate after some rigorous shaking, the wires, tubes and sheets settle at the bottom of the oil, just above the water. The oils trap them. However, zero-dimensional nanomaterials, such as nanospheres do not get trapped.

The researchers, according to the news release, are attempting to anticipate the potential contamination of our water supply by nanomaterials and provide a solution before it happens,

We don’t have to wait until the final vote is in on whether nanomaterials have a positive or negative impact on people’s health and environmental health. With the simplicity of this technique, and how prolific nanomaterials are becoming, removing nanomaterials makes sense. Also, finding ways to effectively remove nanomaterials sooner rather than later could improve the technology’s market potential.

“Ideally for a new technology to be successfully implemented, it needs to be shown that the technology does not cause adverse effects to the environment,” Yap, Zhang and their co-authors write. “Therefore, unless the potential risks of introducing nanomaterials into the environment are properly addressed, it will hinder the industrialization of products incorporating nanotechnology.”

Purifying water and greening nanotechnology could be as simple as shaking a vial of water and oil.

Here’s a video about the research supplied by Michigan Tech,

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

A Simple and Universal Technique To Extract One- and Two-Dimensional Nanomaterials from Contaminated Water by Bishnu Tiwari, Dongyan Zhang, Dustin Winslow, Chee Huei Lee, Boyi Hao, and Yoke Khin Yap. ACS Appl. Mater. Interfaces, 2015, 7 (47), pp 26108–26116 DOI: 10.1021/acsami.5b07542 Publication Date (Web): November 9, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

Making diesel cleaner

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A Dec. 10, 2015 news item on Nanowerk announces a new method for producing diesel fuels (Note: A link has been removed),

Researchers from KU Leuven [Belgium] and Utrecht University [Netherlands] have discovered a new approach to the production of fuels (Nature, “Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons”). Their new method can be used to produce much cleaner diesel. It can quickly be scaled up for industrial use. In 5 to 10 years, we may see the first cars driven by this new clean diesel.

A Dec. 10, 2015 KU Leuven press release, which originated the news item, provides more detail about the research,

The production of fuel involves the use of catalysts. These substances trigger the chemical reactions that convert raw material into fuel. In the case of diesel, small catalyst granules are added to the raw material to sufficiently change the molecules of the raw material to produce useable fuel.

Catalysts can have one or more chemical functions. The catalyst that was used for this particular study has two functions, represented by two different materials: a metal (platinum) and a solid-state acid. During the production process for diesel, the molecules bounce to and fro between the metal and the acid. Each time a molecule comes into contact with one of the materials, it changes a little bit. At the end of the process, the molecules are ready to be used for diesel fuel.

The assumption has always been that the metal and the solid-state acid in the catalyst should be as close together as possible. That would speed up the production process by helping the molecules bounce to and fro more quickly. Professor Johan Martens (KU Leuven) and Professor Krijn de Jong (Utrecht University) have now discovered that this assumption is incorrect. [emphasis mine] If the functions within a catalyst are nanometres apart, the process yields better molecules for cleaner fuel.

“Our results are the exact opposite of what we had expected. At first, we thought that the samples had been switched or that something was wrong with our analysis”, says Professor Martens. “We repeated the experiments three times, only to arrive at the same conclusion: the current theory is wrong. There has to be a minimum distance between the functions within a catalyst. This goes against what the industry has been doing for the past 50 years.”

The new technique can optimise quite a few molecules in diesel. Cars that are driven by this clean diesel would emit far fewer particulates and CO². The researchers believe that their method can be scaled up for industrial use with relative ease, so the new diesel could be used in cars in 5 to 10 years.

The new technique can be applied to petroleum-based fuels, but also to renewable carbon from biomass.

A fifty year old assumption has been found wrong. Interesting, non? In any event, here’s a link to and a citation for the paper,

Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons by Jovana Zecevic, Gina Vanbutsele, Krijn P. de Jong, & Johan A. Martens. Nature 528, 245–248 (10 December 2015)  doi:10.1038/nature16173 Published online 09 December 2015

This paper is behind a paywall.

An enzyme’s atoms are in a subtle dance that can affect protein function

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This research comes from Québec’s Institut national de la recherche scientifique (INRS) according to a Dec. 10, 2015 news item on ScienceDaily,

Infinitesimal fluctuations occurring on the milli- and even nano-second time scales within the three-dimensional structure of enzymes may be one of the keys to explaining protein function. Professor Nicolas Doucet’s team at INRS has demonstrated that even when certain amino acids are far from the active site of an enzyme, a change in their flexibility and atomic fluctuations can significantly impact enzyme activity. This phenomenon, which has been underestimated up to now, could explain certain protein engineering failures and help improve the way synthetic functional enzymes are designed.

A Dec. 10, 2015 INRS news release on EurekAlert, which originated the news item, provides an explanation of an enzyme’s functions and what the researchers found out,

Enzymes are nanomachines that are exceptionally efficient at catalyzing a chemical reaction. They play a role in all cellular mechanisms. Like all proteins, they are made up of amino acid chains that are folded and assembled in a very precise 3D structure. Some enzymes, like ribonuclease A, are so efficient that they catalyze the transformation of chemical molecules thousands of times per second.

In this study, Donald Gagné, a researcher in Professor Doucet’s lab holding a PhD in biology from INRS, analyzed the impact of removing a methyl group located near a loop distant from the reaction site of ribonuclease A–a very slight change that presumably would have no effect. The mutation does not perturb the 3D structure of the enzyme. However, it did result in a four-fold reduction in the affinity of ribonuclease A for nucleotides (molecules to which it must bind to carry out its function). How is this possible?

Using crystallography techniques and nuclear magnetic resonance to examine the enzyme at atomic resolution, Donald Gagné compared normal ribonuclease A with the mutated enzyme. He observed that when ribonuclease A is modified, the nucleotides do not position themselves correctly and have a harder time binding to the active site. It appears that this repositioning is due to an increase in enzyme fluctuations caused by the elimination of this distant methyl group, which we can picture as creating vibrations that spread through the enzyme structure all the way to the site of catalysis.

This demonstration of the importance of enzyme dynamics could change our understanding of protein and enzyme mechanisms. While it remains a challenge to measure fluctuations at this atomic scale, researchers have studied the three-dimensional structure of proteins to understand how they function. Despite the staggering complexity of this phenomenon, we now know that proteins are increasingly regulated by the subtle dance of their atoms.

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

Perturbation of the Conformational Dynamics of an Active-Site Loop Alters Enzyme Activity by Donald Gagné, Rachel L. French, Chitra Narayanan, Miljan Simonović, Pratul K. Agarwal, Nicolas Doucet. Structure Volume 23, Issue 12, p2256–2266, 1 December 2015 DOI: http://dx.doi.org/10.1016/j.str.2015.10.011

This paper is behind a paywall.

Google announces research results after testing 1,097-qubit D-Wave 2X™ quantum computers

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If you’ve been reading this blog over the last few months, you’ll know that I’ve mentioned D-Wave Systems, a Vancouver (Canada)-based quantum computing company, frequently. The company seems to be signing all kinds of deals lately including one with Google (my Oct. 5, 2015 posting). Well, a Dec. 9, 2015 news item on Nanotechnology Now sheds more light on how Google is using D-Wave’s quantum computers,

Harris & Harris Group, Inc. (NASDAQ: TINY), an investor in transformative companies enabled by disruptive science, notes that yesterday [Dec. 8, 2015] NASA, Google and the Universities Space Research Association (USRA) hosted a tour of the jointly run Quantum Artificial Intelligence Laboratory located at the NASA’s Ames Research Center which houses one of D-Wave’s 1,097-qubit D-Wave 2X™ quantum computers. At this event, Google announced that D-Wave’s quantum computer was able to find solutions to complicated problems of nearly 1,000 variables up to 108 (100,000,000) times faster than classical computers.

A Dec. 8, 2015 posting by Hartmut Neven for the Google Research blog describes the research and the results (Note: Links have been removed),

During the last two years, the Google Quantum AI [artificial intelligence] team has made progress in understanding the physics governing quantum annealers. We recently applied these new insights to construct proof-of-principle optimization problems and programmed these into the D-Wave 2X quantum annealer that Google operates jointly with NASA. The problems were designed to demonstrate that quantum annealing can offer runtime advantages for hard optimization problems characterized by rugged energy landscapes. We found that for problem instances involving nearly 1000 binary variables, quantum annealing significantly outperforms its classical counterpart, simulated annealing. It is more than 108 times faster than simulated annealing running on a single core. We also compared the quantum hardware to another algorithm called Quantum Monte Carlo. This is a method designed to emulate the behavior of quantum systems, but it runs on conventional processors. While the scaling with size between these two methods is comparable, they are again separated by a large factor sometimes as high as 108.

For anyone (like me) who needs an explanation of quantum annealing, there’s this from its Wikipedia entry (Note: Links have been removed),

Quantum annealing (QA) is a metaheuristic for finding the global minimum of a given objective function over a given set of candidate solutions (candidate states), by a process using quantum fluctuations. Quantum annealing is used mainly for problems where the search space is discrete (combinatorial optimization problems) with many local minima; such as finding the ground state of a spin glass.[1] It was formulated in its present form by T. Kadowaki and H. Nishimori in “Quantum annealing in the transverse Ising model”[2] though a proposal in a different form had been proposed by A. B. Finilla, M. A. Gomez, C. Sebenik and J. D. Doll, in “Quantum annealing: A new method for minimizing multidimensional functions”.[3]

Not as helpful as I’d hoped but sometimes its necessary to learn a new vocabulary and a new set of basic principles, which takes time and requires the ability to ‘not know’ and/or ‘not understand’ until one day, you do.

In the meantime, here’s more possibly befuddling information from the researchers in the form of a paper on arXiv.org,

What is the Computational Value of Finite Range Tunneling? by Vasil S. Denchev, Sergio Boixo, Sergei V. Isakov, Nan Ding, Ryan Babbush, Vadim Smelyanskiy, John Martinis, Hartmut Neven. http://arxiv.org/abs/1512.02206

This paper is open access.

Policymakers do read science blogs

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The policymakers who attended the ‘science blogging’ session at the 7th annual (2015) Canadian Science Policy Conference (Nov. 25 – 27, 2015) read blogs according to a Dec. 7, 2015 posting by Lisa Willemse and Stephanne Taylor for the Science Borealis blog/aggregator,

Several attendees who represented policy/government bodies said that they do, in fact, watch science blogs closely and do not necessarily view them the same way they do mainstream media. They look to science blogs to ask big, broad questions, to identify grassroots movements that could be brought into policy debates, and to identify key issues in need of further research. To be effective in these ways, the blogs need to be credible. They should present research in narrative, with implications for society rather than a set of uncontextualized data. And they have to be on the policymaker’s radar.

Similar to acquiring a public audience, getting a science blog onto the screen of a policymaker takes additional work, particularly since scientists and policymakers do not necessary belong to similar online communities.

Suggestions for tackling this challenge included creating a database of all MPs [Members of Parliament] or government officials of interest, which includes political and personal interests as well as handles for all of their social media accounts.

When a blog post or other online media is created, it becomes an easy task to identify potential policy targets and direct tweets or other social media messaging to them. Using this method, Genome Alberta was able to garner attention, direct replies and/or retweets from the targeted MPs and MLAs [Members of the Legislative Assembly, the Legislative Assembly is the provinces’ equivalent to Parliament’s House of Commons].

The post covers also covers these topics,

The Scientist Blogger — Speaking to the Curious

Gaining Public Trust — Truth, Passion and Plain Language

There were some additional comments by Willemse and Taylor,

Our original goal was to write a collaborative blog post about the connections between science blogging and policymakers, but this proved awkward to do on the floor.  Instead, we had an organic, wide-ranging conversation with the audience, which was ultimately more productive than sticking to our initial script.

In my Aug. 18, 2015 posting, I critiqued this notion that somehow the participants and panelists would be able to create one or more science policy blog posts in a “hands-on session”,

… Just how are the participants going to have a “hands-on” experience of “interactively writing up a science policy blog post?” There aren’t that many ways to operationalize this endeavour. It’s either a session where people have access to computers and collectively write and post individual pieces under one banner or they submit their posts and someone edits in real time or someone is acting as secretary taking notes from the discussion and summarizing it in a post (not exactly hands-on for anyone except the writer).

Interesting, eh? It seemed obvious to me but not to the organizers, until they were conducting the session.  In any event, I’m glad to see they were able to adjust and the session was successful (in Willemse’s and Taylor’s estimation).

Clues as to how mother of pearl is made

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Iridescence seems to fascinate scientists and a team at Cornell University is no exception (from a Dec. 4, 2015 news item on Nanowerk),

Mother nature has a lot to teach us about how to make things.

With that in mind, Cornell researchers have uncovered the process by which mollusks manufacture nacre – commonly known as “mother of pearl.” Along with its iridescent beauty, this material found on the insides of seashells is incredibly strong. Knowing how it’s made could lead to new methods to synthesize a variety of new materials with as yet unguessed properties.

“We have all these high-tech facilities to make new materials, but just take a walk along the beach and see what’s being made,” said postdoctoral research associate Robert Hovden, M.S. ’10, Ph.D. ’14. “Nature is doing incredible nanoscience, and we need to dig into it.”

A Dec. 4, 2015 Cornell University news release by Bill Steele, which originated the news item, expands on the theme,

Using a high-resolution scanning transmission electron microscope (STEM), the researchers examined a cross section of the shell of a large Mediterranean mollusk called the noble pen shell or fan mussel (Pinna nobilis). To make the observations possible they had to develop a special sample preparation process. Using a diamond saw, they cut a thin slice through the shell, then in effect sanded it down with a thin film in which micron-sized bits of diamond were embedded, until they had a sample less than 30 nanometers thick, suitable for STEM observation. As in sanding wood, they moved from heavier grits for fast cutting to a fine final polish to make a surface free of scratches that might distort the STEM image.

Images with nanometer-scale resolution revealed that the organism builds nacre by depositing a series of layers of a material containing nanoparticles of calcium carbonate. Moving from the inside out, these particles are seen coming together in rows and fusing into flat crystals laminated between layers of organic material. (The layers are thinner than the wavelengths of visible light, causing the scattering that gives the material its iridescence.)

Exactly what happens at each step is a topic for future research. For now, the researchers said in their paper, “We cannot go back in time” to observe the process. But knowing that nanoparticles are involved is a valuable insight for materials scientists, Hovden said.

Here’s an image from the researchers,

Electron microscope image of a cross-section of a mollusk shell. The organism builds its shell from the inside out by depositing layers of calcium carbonate nanoparticles. As the particle density increases over time they fuse into large flat crystals embedded in layers of organic material to form nacre. Courtesy: Cornell University

Electron microscope image of a cross-section of a mollusk shell. The organism builds its shell from the inside out by depositing layers of calcium carbonate nanoparticles. As the particle density increases over time they fuse into large flat crystals embedded in layers of organic material to form nacre. Courtesy: Cornell University

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

Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells by Robert Hovden, Stephan E. Wolf, Megan E. Holtz, Frédéric Marin, David A. Muller, & Lara A. Estroff. Nature Communications 6, Article number: 10097 doi:10.1038/ncomms10097 Published 03 December 2015

This is an open access paper.

Using quantum dots to detect and identify explosives

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This research is courtesy of the University College London (UCL) according to a Dec. 9, 2015 news item on Nanowerk,

A new test for detecting multiple explosives simultaneously has been developed by UCL scientists. The proof-of-concept sensor is designed to quickly identify and quantify five commonly used explosives in solution to help track toxic contamination in waste water and improve the safety of public spaces.

Lead researcher, Dr William Peveler (UCL Chemistry), said: “This is the first time multiple explosives have been detected using a single sensor before, demonstrating proof-of-concept for this approach. Our sensor changes colour within 10 seconds to give information about how much and what explosives are present in a sample. Following further development, we hope it will be used to quickly analyse the nature of threats and inform tailored responses.”

A Dec. 9, 2015 UCL press release (also on EurekAlert), which originated the news item, expands on the theme,

Dr Peveler, added: “We analysed explosives which are commonly used for industrial and military purposes to create a useful tool for environmental and security monitoring. For example, DNT is a breakdown product from landmines, and RDX and PETN have been used in terror plots in recent years as they can be hard to detect using sniffer dogs. Our test can quickly identify these compounds so we see it having a variety of applications from monitoring the waste water of munitions factories and military ranges to finding evidence of illicit activities.”

The sensor is made of quantum dots, which are tiny light-emitting particles or nanomaterials, to which explosive targeting receptors are attached. As each explosive binds to the quantum dot, it quenches the light being emitted to a different degree. The distinct changes in colour are analysed computationally in a variety of conditions to give a unique fingerprint for each compound, allowing multiple explosives to be detected with a single test.

Senior author, Professor Ivan Parkin (UCL Chemistry), said: “Our sensor is a significant step forward for multiple explosives detection. Current methods can be laborious and require expensive equipment but our test is designed to be inexpensive, fast and use a much smaller volume of sample than previously possible. Although all of these factors are important, speed and accuracy are crucial when identifying explosive compounds.”

The team plan to take it from the laboratory into the field by blind testing it with contaminated waste water samples. They also hope to improve the sensitivity of the test by tailoring the surfaces of the quantum dots. Currently, its limit is less than one part per million which the team hope to increase into the part per billion range.

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

Multichannel Detection and Differentiation of Explosives with a Quantum Dot Array by William J. Peveler, Alberto Roldan, Nathan Hollingsworth, Michael J. Porte‡, and Ivan P. Parkin. ACS Nano, Article ASAP DOI: 10.1021/acsnano.5b06433 Publication Date (Web): November 18, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.