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Precise mechanical manipulation of individual long DNA molecules

Electron micrographs demonstrating Aeon Biowares’ patented Molecular Threading technology. Left: DNA molecules threaded onto an electron microscopy grid with an amorphous carbon surface; right: DNA molecules threaded onto a graphene coated grid (credit: Aeon Biowares and KurzweilAI)

Those Nanodot readers who heard very interesting research results from Halcyon Molecular discussed at the Foresight Institute 25th Anniversary Reunion Conference (see here and here and these videos) will be interested in this update on the “Molecular Threading” portion of that technology found on KurzweilAI.net:

Teams of researchers from Harvard University and Halcyon Molecular, Inc. have disclosed “Molecular Threading,” the first technology to allow single DNA molecules to be drawn from solution and precisely manipulated, allowing for faster, cheaper, more accurate DNA sequencing.

This novel technology pulls single high-molecular weight DNA molecules from solution into air and then places them onto any surface. Halcyon Molecular developed the processes and the intellectual property is now owned by Palo Alto-based biotechnology firm Aeon Biowares.

“Molecular Threading offers a unique means of reaching from the macroscopic world into the world of large molecules with unprecedented exactitude,” says Dr. Chris Melville, CEO of Aeon Biowares and former Director of Chemistry at Halcyon Molecular. …

Additional details from the Aeon Biowares news release: “Molecular Threading, News of the First Public Disclosure

Molecular Threading was invented by brothers Michael and William Andregg, the co-founders of Halcyon Molecular, Inc. Both co-authors on the current paper [open access: Molecular Threading: Mechanical Extraction, Stretching and Placement of DNA Molecules from a Liquid-Air Interface], the Andregg brothers were previously the subjects of a major profile in the national UK-based newspaper The Independent (“Silicon Valley: The anatomy of a cutting-edge start-up“, Sunday 14 August 2011).

The invention was spurred by the Andregg brothers’ quest for faster, cheaper, and more accurate DNA sequencing technologies. In particular, they needed a way to place DNA molecules onto surfaces in a more controlled manner than current techniques allow. As they tried many different techniques, including methods that are contrasted in the paper, they made an elegant discovery. A simple glass needle tip pulled from a Bunsen flame and coated with a hydrophobic polymer could stretch individual DNA molecules from water into air and place them onto a surface. Furthermore, due to the tension between the needle and the liquid, the DNA molecule is stretched in a geometrically predictable and reproducible way. The movie linked to here from the paper’s Supplementary Information shows how a bundle of DNA molecules remain normal to an air-water interface when stretched into air by the needle: DNA Thread Normal to Droplet Surface.

By attaching the needle to a piezo-positioner, they were soon able to make arrays of parallel stretched molecules as shown in the electron micrographs above. The image on the left shows DNA molecules threaded onto an electron microscopy grid with an amorphous carbon surface, while the image on the right shows DNA molecules threaded onto a graphene coated grid.

Molecular Threading is the enabling technology that allowed researchers for the first time to know the exact physical location of the DNA backbone. This together with the reproducible stretching meant that images that reveal the positions of the DNA bases could be used to determine the nucleotide sequence. This soon attracted the interest of Founders Fund partners Luke Nosek, Peter Thiel and Elon Musk, whose investments allowed the team to exploit Molecular Threading for DNA sequencing by electron microscopy.

Further characterization of the invention was performed by a collaboration of researchers working at Harvard University in the lab of George Church and by several researchers at Halcyon Molecular, some of whom are now working at Aeon Biowares. This includes Halcyon founding team member Kent Kemmish, now founder and CTO at Aeon Biowares.

“This is the first time anyone has ever pulled single high-molecule weight DNA molecules—or any macromolecules for that matter—out of solution and positioned them in a controlled way,” says Kemmish. “Though still in pre-commercial development, it is arguably one of the most advanced nanotechnologies in existence today.”

This advance is a very important nanotechnology that is especially important for DNA sequencing, and thus for personalized medicine, a major component of future medical technology. Much genomic DNA is riddled with many copies of repeated sequences. Current sequencing methods can only read a few hundred nucleotides at a time, so that determining the unique sequences flanking each copy of a repeated sequence can be very difficult. Precise manipulation of long DNA molecules opens the way to reading much longer sequences than can be done with current technology. The disclosure publication speculates “Applications beyond sequencing include nanofabrication, such as aperiodic templates for organic or inorganic materials using DNA as an organizing scaffold, or precision-patterned DNA nanowire arrays.” Organizing complex arrays of catalytic properties could be a step toward building complex molecular machine systems, perhaps as a step toward atomically precise manufacturing.
—James Lewis, PhD

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Circuits of graphitic nanoribbons grown from aligned DNA templates

Representation of DNA Assembly of Graphene Transistor. To the right is a honeycomb of graphene atoms. To the left is a double strand of DNA. The white spheres represent copper ions integral to the chemical assembly process. The fire represents the heat that is an essential ingredient in the technique. (Credit: Anatoliy Sokolov of the Bao Group)

The “molecular threading” technique disclosed by Aeon Biowares that was the topic of our previous post was presented as a great improvement over earlier bulk methods for stretching DNA, such as “molecular combing”, and the researchers speculated that it might also be useful for fabricating arrays of nanowires. As a starting point to thinking about what molecular threading might make possible, it might be useful to consider what current methods like molecular combing can accomplish. A hat tip to Josh Hall for pointing to this example of what can already be done in terms of using DNA strands to assemble functional arrays “Stanford scientists use DNA to assemble a transistor from graphene“.

DNA is the blueprint for life. Could it also become the template for making a new generation of computer chips based not on silicon, but on an experimental material known as graphene?

That’s the theory behind a process that Stanford chemical engineering professor Zhenan Bao reveals in Nature Communications [abstract]. …

Graphene has the physical and electrical properties to become a next-generation semiconductor material – if researchers can figure out how to mass-produce it.

Graphene is a single layer of carbon atoms arranged in a honeycomb pattern. Visually it resembles chicken wire. Electrically this lattice of carbon atoms is an extremely efficient conductor.

Bao and other researchers believe that ribbons of graphene, laid side-by-side, could create semiconductor circuits. Given the material’s tiny dimensions and favorable electrical properties, graphene nano ribbons could create very fast chips that run on very low power, she said.

“However, as one might imagine, making something that is only one atom thick and 20 to 50 atoms wide is a significant challenge,” said co-author Sokolov.

To handle this challenge, the Stanford team came up with the idea of using DNA as an assembly mechanism.

Physically, DNA strands are long and thin, and exist in roughly the same dimensions as the graphene ribbons that researchers wanted to assemble.

Chemically, DNA molecules contain carbon atoms, the material that forms graphene.

The real trick is how Bao and her team put DNA’s physical and chemical properties to work.

The researchers started with a tiny platter of silicon to provide a support (substrate) for their experimental transistor. They dipped the silicon platter into a solution of DNA derived from bacteria and used a known technique to comb the DNA strands into relatively straight lines.

Next, the DNA on the platter was exposed to a copper salt solution. The chemical properties of the solution allowed the copper ions to be absorbed into the DNA.

Next the platter was heated and bathed in methane gas, which contains carbon atoms. Once again chemical forces came into play to aid in the assembly process. The heat sparked a chemical reaction that freed some of the carbon atoms in the DNA and methane. These free carbon atoms quickly joined together to form stable honeycombs of graphene.

“The loose carbon atoms stayed close to where they broke free from the DNA strands, and so they formed ribbons that followed the structure of the DNA,” Yap said.

So part one of the invention involved using DNA to assemble ribbons of carbon. But the researchers also wanted to show that these carbon ribbons could perform electronic tasks. So they made transistors on the ribbons.

“We demonstrated for the first time that you can use DNA to grow narrow ribbons and then make working transistors,” Sokolov said.

The paper drew praise from UC Berkeley associate professor Ali Javey, an expert in the use of advanced materials and next-generation electronics.

“This technique is very unique and takes advantage of the use of DNA as an effective template for controlled growth of electronic materials,” Javey said. “In this regard the project addresses an important research need for the field.”

Bao said the assembly process needs a lot of refinement. For instance, not all of the carbon atoms formed honeycombed ribbons a single atom thick. In some places they bunched up in irregular patterns, leading the researchers to label the material graphitic instead of graphene.

Even so, the process, about two years in the making, points toward a strategy for turning this carbon-based material from a curiosity into a serious contender to succeed silicon.

“Our DNA-based fabrication method is highly scalable, offers high resolution and low manufacturing cost,” said co-author Yap. “All these advantages make the method very attractive for industrial adoption.”

This paper demonstrates using DNA molecules aligned and stretched by molecular combing to bind copper ions, which act as catalysts of chemical vapor deposition for the growth of graphitic (that is, they contained both sp2 and sp3 carbon atoms) nanoribbons less than 10 nm in width and more than 20 µm in length. The graphitic nanoribbons mimicked the DNA nanostructures used as templates in terms of density, bundling, and branching of strands. In these experiments the only way in which the density, bundling, and branching of these double-strand DNA molecules could be controlled was by DNA concentration and ionic strength. The authors focus on the need to better control reduction of metal ions and growth conditions to yield pristine single-layer graphene nanoribbons. It is also interesting to speculate on what increased complexity of circuitry could results from using molecular threading to arrange DNA templates.
—James Lewis, PhD

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Carbyne: the strongest, stiffest carbon chain

Carbyne ropes and rods. Credit: Vasilii Artyukhov/Rice University

Carbyne – a straight line of carbon atoms linked by double bonds or by alternating single and triple bonds — is the next stiff, carbon-based structure with unusual and desirable properties. It has been observed under limited natural and experimental conditions, is expected to be difficult to synthesize and store, and now has been theoretically characterized.

Researchers at Rice University recently published DFT characterizations of carbyne ropes and rods, and overviews of the findings and prospects are reprinted at Phys.org:

According to the portrait drawn from calculations by Yakobson and his group:

  • Carbyne’s tensile strength – the ability to withstand stretching – surpasses “that of any other known material” and is double that of graphene. (Scientists had already calculated it would take an elephant on a pencil to break through a sheet of graphene.)
  • It has twice the tensile stiffness of graphene and carbon nanotubes and nearly three times that of diamond.
  • Stretching carbyne as little as 10 percent alters its electronic band gap significantly.
  • If outfitted with molecular handles at the ends, it can also be twisted to alter its band gap. With a 90-degree end-to-end rotation, it becomes a magnetic semiconductor.
  • Carbyne chains can take on side molecules that may make the chains suitable for energy storage.
  • The material is stable at room temperature, largely resisting crosslinks with nearby chains.


Not unlike the problems of waviness in bundles of carbon nanotube, trying to utilize bundles of carbyne ropes/rods may present challenges:

The literature seemed to indicate carbyne “was not stable and would form graphite or soot,” he said.

Instead, the researchers found carbon atoms on separate strings might overcome the barrier in one spot, but the rods’ stiffness would prevent them from coming together in a second location, at least at room temperature. “They would look like butterfly wings,” Artyukhov said.

“Bundles might stick to each other, but they wouldn’t collapse completely,” Yakobson added. “That could make for a highly porous, random net that may be good for adsorption.” Artyukhov said the nominal specific area of carbyne is about five times that of graphene.

They’re taking a more rigorous look at the conductivity of carbyne and are thinking about other elements as well. “We’ve talked about going through different elements in the periodic table to see if some of them can form one-dimensional chains,” Yakobson said.

-Posted by Stephanie C

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Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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Rating: 0.0/10 (0 votes cast)
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Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

VN:F [1.9.17_1161]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.17_1161]
Rating: 0 (from 0 votes)

Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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Rating: 0 (from 0 votes)

Defective nanotubes turned into light emitters

UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices.

Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. “It is extremely efficient in ultraviolet light emission, one of the best currently available on the market,” remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU’s NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. “We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying,” he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. “We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show,” and they did in fact show, “that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable.”

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. “All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions.”

Rubio highlighted “the simplicity” of the device proposed. “It’s a device that functions with defects, it does not have to be pure, and it’s very easy to build and control.” Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. “It has a traditional transistor configuration, and what we are proposing would work with current electronic devices,” he stressed. The “less attractive” part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: “It’s a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it’s like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining.”

Further information

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof Ángel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council – Rome), who are three veteran researchers in the group.

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