Tag Archives: copper wire

Nanoscale light confinement without metal (photonic circuits) at the University of Alberta (Canada)

To be more accurate, this is a step forward towards photonic circuits according to an Aug. 20, 2014 news item on Azonano,

The invention of fibre optics revolutionized the way we share information, allowing us to transmit data at volumes and speeds we’d only previously dreamed of. Now, electrical engineering researchers at the University of Alberta are breaking another barrier, designing nano-optical cables small enough to replace the copper wiring on computer chips.

This could result in radical increases in computing speeds and reduced energy use by electronic devices.

“We’re already transmitting data from continent to continent using fibre optics, but the killer application is using this inside chips for interconnects—that is the Holy Grail,” says Zubin Jacob, an electrical engineering professor leading the research. “What we’ve done is come up with a fundamentally new way of confining light to the nano scale.”

At present, the diameter of fibre optic cables is limited to about one thousandth of a millimetre. Cables designed by graduate student Saman Jahani and Jacob are 10 times smaller—small enough to replace copper wiring still used on computer chips. (To put that into perspective, a dime is about one millimetre thick.)

An Aug. 19, 2014 University of Alberta news release by Richard Cairney (also on EurekAlert), which originated the news item, provides more technical detail and information about funding,

 Jahani and Jacob have used metamaterials to redefine the textbook phenomenon of total internal reflection, discovered 400 years ago by German scientist Johannes Kepler while working on telescopes.

Researchers around the world have been stymied in their efforts to develop effective fibre optics at smaller sizes. One popular solution has been reflective metallic claddings that keep light waves inside the cables. But the biggest hurdle is increased temperatures: metal causes problems after a certain point.

“If you use metal, a lot of light gets converted to heat. That has been the major stumbling block. Light gets converted to heat and the information literally burns up—it’s lost.”

Jacob and Jahani have designed a new, non-metallic metamaterial that enables them to “compress” and contain light waves in the smaller cables without creating heat, slowing the signal or losing data. …

The team’s research is funded by the Natural Sciences and Engineering Research Council of Canada and the Helmholtz-Alberta Initiative.

Jacob and Jahani are now building the metamaterials on a silicon chip to outperform current light confining strategies used in industry.

Given that this work is being performed at the nanoscale and these scientists are located within the Canadian university which houses Canada’s National Institute of Nanotechnology (NINT), the absence of any mention of the NINT comes as a surprise (more about this organization after the link to the researchers’ paper).

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

Transparent subdiffraction optics: nanoscale light confinement without metal by Saman Jahani and Zubin Jacob. Optica, Vol. 1, Issue 2, pp. 96-100 (2014) http://dx.doi.org/10.1364/OPTICA.1.000096

This paper is open access.

In a search for the NINT’s website I found this summary at the University of Alberta’s NINT webpage,

The National Institute for Nanotechnology (NINT) was established in 2001 and is operated as a partnership between the National Research Council and the University of Alberta. Many NINT researchers are affiliated with both the National Research Council and University of Alberta.

NINT is a unique, integrated, multidisciplinary institute involving researchers from fields such as physics, chemistry, engineering, biology, informatics, pharmacy, and medicine. The main focus of the research being done at NINT is the integration of nano-scale devices and materials into complex nanosystems that can be put to practical use. Nanotechnology is a relatively new field of research, so people at NINT are working to discover “design rules” for nanotechnology and to develop platforms for building nanosystems and materials that can be constructed and programmed for a particular application. NINT aims to increase knowledge and support innovation in the area of nanotechnology, as well as to create work that will have long-term relevance and value for Alberta and Canada.

The University of Alberta’s NINT webpage also offers a link to the NINT’s latest rebranded website, The failure to mention the NINT gets more curious when looking at a description of NINT’s programmes one of which is hybrid nanoelectronics (Note: A link has been removed),

Hybrid NanoElectronics provide revolutionary electronic functions that may be utilized by industry through creating circuits that operate using mechanisms unique to the nanoscale. This may include functions that are not possible with conventional circuitry to provide smaller, faster and more energy-efficient components, and extend the development of electronics beyond the end of the roadmap.

After looking at a list of the researchers affiliated with the NINT, it’s apparent that neither Jahani or Jacob are part of that team. Perhaps they have preferred to work independently of the NINT ,which is one of the Canada National Research Council’s institutes.

CurTran and its plan to take over the world by replacing copper wire with LiteWire (carbon nanotubes)

This story is about carbon nanotubes and commercialization if I read Molly Ryan’s April 14, 2014 article for the Upstart Business Journal correctly,

CurTran LLC just signed its first customer contract with oilfield service Weatherford International Ltd. (NYSE: WFT) in a deal valued at more than $350 million per year.

To say the least, this is a pretty big step forward for the Houston-based nanotechnology materials company, especially since Gary Rome, CurTran’s CEO, said the entire length of the contract is valued at more than $7 billion. But when looking at the grand scheme of CurTran’s plans, this $7 billion contract is a baby step.

“We want to replace copper wire,” Rome said. “Globally, copper is used everywhere and it is a huge market. … We (have a product) that is substantially stronger than copper, and our electrical properties are in common.”

Rice University professor Richard Smalley began researching what would eventually become CurTran’s LiteWire product more than nine years ago, and CurTran officially formed in 2011.

CurTran, which is based in Houston, Texas, describes its LiteWire product this way,

Copper is a better conductor than Aluminum and Steel, and silver is too expensive to use in most applications.  So LiteWire is benchmarked against the dominant conductor in the market, copper.

So how does LiteWire match up against copper wire and cable?

Electrically, in established power transmission wiring standards and frequency, LiteWire has the same properties as copper conductors.  Resistivity, impedance, loading, sizing, etc, copper and LiteWire are the same at 60HZ.  This was intentional by our engineering department, ease adoption of LiteWire.  No need to change wire coating, cable winding, or wire processing equipment or processes, just change over to LiteWire and go.  Every electrician can work with LiteWire utilizing the same tools, standards and instruments.

So what is different between Copper Wire and LiteWire?

It’s Carbon.  LiteWire is an aligned structure double wall carbon nano-tube’s in wire form.  It is a 99.9% carbon structure that takes advantage of the free electrons available in carbon, while limiting the ability of the carbon to form new molecules, such as COx.  The outer electrons of carbon are loosely bound and easily conduced to move from atom to atom.

It is light.  LiteWire is 1/5th the weight of copper conductors.  A 40lb spool of 10ga 3-wire copper wire has 200 feet of wire.  A 40lb spool of 10ga 3-wire LiteWire has 800 feet of wire.  Aluminum wire is ½ the weight of copper, yet requires a 50% larger diameter wire for the same conductive properties, LiteWire sizing is exactly the same as copper.

It is strong.  LiteWire is stronger than steel, 20 times stronger than copper, and stronger than 8000 series Aluminum cable.  Span greater distances between towers, pull higher tension, reduce installation costs and maintenance.

It doesn’t creep.  LiteWire expands and contracts 1/3 less than copper and its aluminum equivalents.  Connection points are secure year round and year after year.  Less sagging of power lines in hot temperatures, less opportunity for grounding of power lines and power outages.

More power, less loss.  LiteWire is equal to copper wire at 60HA, and highly efficient at higher frequencies, voltages and amperes.  More electrical energy can be transmitted with lower losses in the system.  Less wasted energy in the line, means less power needs to be produced.

A longer life.  LiteWire is noncorrosive in all naturally occurring environments, from deep sea to outer space. No issue with dissimilar metals at connection points.  LiteWire is inert and does not degrade over time.

Can you hear me now.  Litewire is the perfect signal conducting wire.  LiteWire is superior at higher frequencies, losses are lower and signal clarity is greater.  Networks can carry more bandwidth and signal separation is cleaner.

Never wet.  LiteWire is hydrophobic by nature.  Water beads up and is shed, even if the water freezes, it does so in bead form and falls away.  No more powerline failures from ice buildup and breaking or shorting due to line sag.

How much does it cost.  LiteWire costs the same as copper wire of equal length and size.  As the price of copper continues to rise and as new LiteWire facilities come on line, the cost of LiteWire will decrease. Projecting out ten years, LiteWire will be half the cost of copper wire and cable.

Never fatigues.  LiteWire has a very long fatigue life, we are still looking for it.  LiteWire is not susceptible to fatigue failure.  LiteWire’s bonds are at the atomic level, when that bond is broken, the failure occurs.  Repeated cycles to near the breaking point do not degrade LiteWire’s integrity.  Metal conductors fatigue under repeated bending, reducing their load carrying capabilities and subsequent failure.

There is a table of specific technical properties on the LiteWire product webpage.

CurTran’s CEO has big plans (from the Ryan article),

With a multibillion-dollar contract under its belt only a few years after its founding, Rome intends for CurTran to have blockbuster years for the next five years. According to the company’s website, it plans to hire 3,600 new employees around the world in this time frame.

“We also plan to open a new production facility every six months for the next five years,” Rome said. “We’ve already identified the first four locations.”

For Weatherford’s perspective on this deal, there’s the company’s April 7, 2014 news release,

Weatherford International Ltd. today [April 7, 2014] announced that it has entered into an agreement with CurTran LLC to use, sell, and distribute LiteWire, the first commercial scale production of a carbon nanotube technology in wire and cable form.

“With LiteWire products, we gain exclusivity to a revolutionary technology that will greatly add value to our business,” said Dharmesh Mehta, chief operating officer for Weatherford. “The use of LiteWire products allows us to provide safer, faster, and more economic solutions for our customers.”

In addition to using LiteWire in its global operations, Weatherford will be the exclusive distributor of this product in the oil and gas industry.

Interestingly, Weatherford seems to be in a highly transitional state. From an April 3, 2014 article by Jordan Blum for Houston Business Journal (Note: Links have been removed),

Weatherford International Ltd. (NYSE: WFT) plans to move its corporate headquarters from Switzerland to Ireland largely because of changes to Swiss corporate executive laws and potential uncertainties.

Weatherford, which has its operational headquarters in Houston, is  undergoing a global downsizing as it relocates its corporate offices.

Weatherford President and CEO Bernard Duroc-Danner said the move will help the company “quickly and efficiently execute and move forward on our transformational path.”

The downsizing and move put a different complexion on Weatherford’s deal with CurTran. It seems Weatherford is taking a big gamble on its future. I’m basing that comment on the fact that there is, to my knowledge, no other deployment of a similar scope of a ‘carbon nanotube’ wire such as LightWire.

It would appear from CurTran’s Overview that LightWire’s deployment is an inevitability,

CurTran LLC was formed for one purpose.  To industrialize the production of Double Wall Carbon Nanotubes in wire form to be a direct replacement for metallic conductors in wire and cable applications.

That rhetoric is worthy of a 19th century capitalist. Of course, those guys did change the world.

There’s a bit more about the company’s history and activities from the Overview page,

CurTran was formed in 2011 by industrial manufacturing, engineering and research organizations.  An industrialization plan was defined, customer and industry partners engaged, the intellectual property consolidated and operations launched.

Operations are based in the following areas:

  • Corporate Headquarters, located in Houston Texas
  • Test Facility, located in Houston Texas and operated by NanoRidge and Rice University researchers.
  • Pilot Plant located in Eastern Europe
  • Production facilities are to be located in various global markets.  Production facilities will be fully operational in 2014 producing in excess of 50,000 tonnes per facility annually.

CurTran manufactures the LiteWire conductor in many forms.  We do not manufacture insulated products at this time.  We rely on our Joint Venture Partners to deliver a completed wire/cable product to their existing customer base.

CurTran provides engineering services to Partners and Customers that seek to optimize their products to the full capabilities of LiteWire.

CurTran supports ongoing research and development activities in applied material science, chemical/mechanical/thermo/fluid production processes, industrial equipment design, and  application sciences.

Getting back to Weatherford, I imagine there is celebration in Ireland although I can’t help wondering if the Swiss, in a last minute solution, might not find a way to keep Weatherford’s headquarters right where they are. I haven’t been able to find a date for Weatherford’s move to Ireland.

Quadruple the amount of electrical current by using carbon nanotube-based fibers

The announcement from Rice University was written in an interesting fashion. The good news is that you can quadruple the amount of electrical current being carried by substituting copper with carbon nanotube-based fibers. Unfortunately, expectations are set for a much higher rate before the good news is revealed in this Feb.  14, 2013 news item on ScienceDaily,

On a pound-per-pound basis, carbon nanotube-based fibers invented at Rice University have greater capacity to carry electrical current than copper cables of the same mass, according to new research.

While individual nanotubes are capable of transmitting nearly 1,000 times more current than copper, the same tubes coalesced into a fiber using other technologies fail long before reaching that capacity.

But a series of tests at Rice showed the wet-spun carbon nanotube fiber still handily beat copper, carrying up to four times as much current as a copper wire of the same mass. [emphasis mine]

That, said the researchers, makes nanotube-based cables an ideal platform for lightweight power transmission in systems where weight is a significant factor, like aerospace applications.

The Feb. 13, 2014 Rice University news release (dated as Feb. 14, 2014 on EurekAlert), which originated the news item, provides context for this discovery (Note: Links have been removed),

The analysis led by Rice professors Junichiro Kono and Matteo Pasquali appeared online this week [week of Feb. 10 – 14, 2014] in the journal Advanced Functional Materials. Just a year ago [2013] the journal Science reported that Pasquali’s lab, in collaboration with scientists at the Dutch firm Teijin Aramid, created a very strong conductive fiber out of carbon nanotubes.

Present-day transmission cables made of copper or aluminum are heavy because their low tensile strength requires steel-core reinforcement.

Scientists working with nanoscale materials have long thought there’s a better way to move electricity from here to there. Certain types of carbon nanotubes can carry far more electricity than copper. The ideal cable would be made of long metallic “armchair” nanotubes that would transmit current over great distances with negligible loss, but such a cable is not feasible because it’s not yet possible to manufacture pure armchairs in bulk, Pasquali said.

I have a couple of notes (1) the 2013 work on ‘armchair’ carbon nanotubes was featured here in a Feb. 6, 2013 posting and (2) Teijin Aramid is located in the Netherlands while its parent company, Teijin, is located in Japan (you can find more about Teijin in this Wikipedia essay).

Getting back to this latest work from Rice (from the news release),

In the meantime, the Pasquali lab has created a method to spin fiber from a mix of nanotube types that still outperforms copper. The cable developed by Pasquali and Teijin Aramid is strong and flexible even though at 20 microns wide, it’s thinner than a human hair.

Pasquali turned to Kono and his colleagues, including lead author Xuan Wang, a postdoctoral researcher at Rice, to quantify the fiber’s capabilities.

Pasquali said there has been a disconnect between electrical engineers who study the current carrying capacity of conductors and materials scientists working on carbon nanotubes. “That has generated some confusion in the literature over the right comparisons to make,” he said. “Jun and Xuan really got to the bottom of how to do these measurements well and compare apples to apples.”

The researchers analyzed the fiber’s “current carrying capacity” (CCC), or ampacity, with a custom rig that allowed them to test it alongside metal cables of the same diameter. The cables were tested while they were suspended in the open air, in a vacuum and in nitrogen or argon environments.

Electric cables heat up because of resistance. When the current load exceeds the cable’s safe capacity, they get too hot and break. The researchers found nanotube fibers exposed to nitrogen performed best, followed by argon and open air, all of which were able to cool through convection. The same nanotube fibers in a vacuum could only cool by radiation and had the lowest CCC.

“The outcome is that these fibers have the highest CCC ever reported for any carbon-based fibers,” Kono said. “Copper still has better resistivity by an order of magnitude, but we have the advantage that carbon fiber is light. So if you divide the CCC by the mass, we win.”

Kono plans to further investigate and explore the fiber’s multifunctional aspects, including flexible optoelectronic device applications.

Pasquali suggested the thread-like fibers are light enough to deliver power to aerial vehicles. “Suppose you want to power an unmanned aerial vehicle from the ground,” he mused. “You could make it like a kite, with power supplied by our fibers. I wish Ben Franklin were here to see that!”

Pasquali and his team’s latest research can be found here,

High-Ampacity Power Cables of Tightly-Packed and Aligned Carbon Nanotubes by Xuan Wang, Natnael Behabtu, Colin C. Young, Dmitri E. Tsentalovich, Matteo Pasqua, & Junichiro Kono. Advanced Functional Materials, Article first published online: 13 FEB 2014 DOI: 10.1002/adfm.201303865

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

This study is behind a paywall.