Raw Carbon Nanotubes vs DexMat Material

Here we show the difference between raw carbon nanotubes and the carbon nanotube yarns and films that we make at DexMat.

Carbon nanotube yarn taps nerves for electroceutical treatments and diagnostics

(Nanowerk News) Ingested or injected pharmaceuticals can target specific molecules involved in disease processes, but get distributed throughout the body where they can cause unwanted side effects. An approach known as electroceuticals aims to avoid systemic exposure by using small wires to electrically monitor and manipulate individual nerves that control organ function and carry information about disease. Despite the promise of electroceuticals, it has been challenging to develop long-term therapies due to the lack of biocompatible wires.
Now, NIBIB-funded researches have spun carbon nanotubes into flexible, nerve-sized wires or yarns capable of high-fidelity long-term connections in live animals. The development of these biocompatible yarns opens the possibility of new bioelectric diagnostics and therapies through regulation of internal organ function at the single nerve level.
Individual carbon nanotubes are pulled from a substrate and spun into the flexible carbon nanotube yarn
Individual carbon nanotubes are pulled from a substrate and spun into the flexible carbon nanotube yarn. (© NPG)
All the organs of the body such as the heart, lungs, liver, and kidneys are automatically controlled by nerves that stretch from the brainstem to each organ. These nerves control organ functions such as heartbeat, breathing rates, and blood pressure, making constant adjustments in response to environmental and physiological changes. Variations in the electrical activity in this area of the brain, known as the autonomic nervous system, can also be predictors, indicators or causes of disease development.
“Monitoring and manipulating the autonomic nervous system to both understand and potentially treat disease has been an intriguing yet understudied approach to medicine,” explains Michael Wolfson, Ph.D., director of the NIBIB program in Rehabilitation Engineering and Implantable Medical Devices. “This is largely due to technical limitations in being able to insert wires into nerves that can reliably and safely record electrical activity over long periods of time and under different physiological conditions.”
In a study reported in the journal Scientific Reports (“Chronic interfacing with the autonomic nervous system using carbon nanotube (CNT) yarn electrodes”), bioengineers at Case Western Reserve University in Cleveland, Ohio describe the development of highly flexible carbon nanotube (CNT) yarn electrodes that were capable of months-long electrical recording in major nerves of the autonomic nervous system in rats.
The CNT yarns are essentially, just that, yarns made from a “forest” of hundreds of carbon nanotubes that are pulled from the metal surface they are grown on and spun into a highly flexible, highly conductive wire 1/100th the size of a human hair.
carbon nanotube yarn is wound around a tungsten needle for insertion into a nerve
The carbon nanotube yarn is wound around a tungsten needle for insertion into a nerve. The coiling of the yarn causes it to remain solidly embedded in the nerve after the needle is withdrawn. Actual needle and yarn (top). Diagram showing detail of how yarn is wrapped around the needle for insertion (bottom). (© NPG)
Current technologies for recording electrical signals from nerves include relatively large stiff tungsten needles used by neurologists to obtain readings from single nerves of patients for several hours, but must be removed before causing lasting nerve damage. Other wire electrode technologies can record nerve signals for short periods but because of their dimensions and stiff mechanical properties they are not suitable for long-term recording in small nerves.
“The currently available electrode technologies simply do not match the mechanical properties of nerves,” explains Dominique Durand, Ph.D., Professor of Biomedical Engineering at Case Western and senior researcher on the CNT yarn work. “With those types of electrodes, it’s often like sticking glass into spaghetti. Our CNT yarns are similar in size and flexibility to actual nerves. These properties allow them to be stealthily inserted into specific nerves and remain there for months without destroying the tissue or inducing an attack by the immune system.”
The combination of the biocompatibility of the CNT yarns and their outstanding ability to carry an electrical signal that is 10 times stronger than current technologies makes them ideal for long term recording of specific nerve signals. Finally, the lack of nerve damage keeps the surrounding axons intact, which helps to eliminate background noise. Thus, the CNT yarns have an excellent signal to noise ratio (SNR), which is critical for this type of research.
The group tested the CNT yarns in two major nerves in the autonomic system in rats. One study involved the vagus nerve, which stretches throughout the body to connect to numerous organs. The nerve is known to control and monitor a range of functions including heart rate, digestive tract movement, sweating, and immune response.
CNT yarn electrodes were also inserted into the glossopharyngeal nerve. The nerve is connected to a number of organs including the carotid artery, and parts of the ear, tongue and salivary glands where it is known to be involved in swallowing.
Carbon nanotube yarn embedded into the vagus nerve of a rat
Carbon nanotube yarn embedded into the vagus nerve of a rat. (© NPG)
In both nerves, recordings of stable electrical activity were maintained over a 10-week period. Pulses of nerve activity were also monitored while the animal responded to physiological challenges. The challenges included distension of the rat’s stomach with saline solution, and short durations where the rats were in low oxygen environments. In each case, the physiological changes induced by the challenge resulted in easily detectable changes in electrical activity that were recorded using the CNT yarn implants over the entire 10-week period of the experiments.
“Although this is early research, we believe the results demonstrate that this technology can be used for reliable long term electrical monitoring of physiological functions,” says Durand. “This is an important step in pursuing monitoring of disease progression through the nerves that control the function of the diseased organ.”
Durand explains that the goal is to learn what electrical signatures or profiles are indicative of disease development and to use that for early intervention, potentially by electrical stimulation or even blocking of the nerve. For example, one therapy for severe hypertension is the cutting of the renal nerve. This is obviously irreversible. Durand, explained that CNT yarn electrodes could be used to block the nerve impulse without cutting the nerve, making the treatment reversible.
The group is also excited about the potential of this recording method to improve prosthetics. “When an arm has been amputated there are tens of thousands of neurons remaining,” said Durand. “The approach would be to insert the CNT yarns into individual nerves and record the electrical signals that are created as the individual thinks about moving the missing arm—essentially learning the electrical signals that are formed by the intention to move the arm.” The ultimate goal is to develop neural interfaces capable of translating those electrical signals into better control of the prosthetic by the user.
Source: National Institute of Biomedical Imaging and Bioengineering

Physics Charge Smartphones Clothes Made From Carbon Nanotubes

Physicists from the University of Cincinnati will soon be able to charge smartphones using clothes made from carbon nanotubes. With the assistance of their colleagues from the BBC, Wright-Patterson, the experts intend to create a special material, which because of the peculiarities of carbon nanotubes would be exceptionally heat-resistant conducting electricity, and will also differ for their durability. Professor mark Schultz, is also involved in the study declared that the task of scientists is to use the resistance and conductivity for energy storage, which can charge a variety of gadgets.

Schulz said that at the moment the science is on the verge of a “carbon revolution,” as this material may soon completely replace metals because of its strength, low weight and various additional properties. Yarns made from nanotubes can store energy, replacing bulky batteries, which soon altogether sink into oblivion.

Full Article: https://sivtelegram.media/physics-charge-smartphones-clothes-made-from-carbon-nanotubes/30672/

Scientists fine-tune carbon nanotubes for flexible, fingertip-wearable terahertz imagers

Researchers at Tokyo Institute of Technology have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.

Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.

The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano is of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology (Tokyo Tech). In 2016 he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.

Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.

Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.

Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.

By making use of a technology known as ionic liquid gating[1], the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility.

“Additionally,” the team says, “we developed gate-free Fermi-level[2] tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p?n junction[3] CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope.

The bendability of the new THz imager and the possibility of even further fine-tuning will expand the range of CNT-based devices that could be developed in the near future.

Moreover, low-cost fabrication methods such as inkjet coating could make large-area THz imaging devices more readily available.

Technical terms

[1] Ionic liquid gating: A technique used to modulate a material’s charge carrier properties.

[2] Fermi level: A measure of the electrochemical potential for electrons, which is important for determining the electrical and thermal properties of solids. The term is named after the Italian-American physicist Enrico Fermi.

[3] p-n junction: Refers to the interface between positive (p-type) and negative (n-type) semiconducting materials. These junctions form the basis of semiconductor electronic devices.

Tokyo Institute of Technology. “Scientists fine-tune carbon nanotubes for flexible, fingertip-wearable terahertz imagers.” ScienceDaily. ScienceDaily, 28 June 2018. <www.sciencedaily.com/releases/2018/06/180628105041.htm>

New Knitting Technique Produces Electronic Smart Fabrics at Industrial Scales

New Knitting Technique Produces Electronic Smart Fabrics at Industrial Scales

Meet the bike shorts of the future.

Image: BluIz60/Shutterstock.com

Australian scientists have developed a knitting technique capable of producing electrically-conductive Spandex-carbon nanotube hybrid textiles at industrial scales. As described earlier this month in a paper published in ACS Nano, http://pubs.acs.org/doi/abs/10.1021/acsnano.6b04125 the stretchable fabrics “exhibit excellent performance” as sensors and artificial muscles. Potential applications include adjustable smart clothing, robotics, and medical devices.

At the core of the material is regular old Spandex, which is basically artificial super-rubber spun into fibers. In the process outlined in the paper, SPX filaments are coated with aerogel sheets of carbon nanotubes. Carbon nanotubes have the neat property of tunable electrical conductivity, and by tweaking the fabrication process, it’s possible to create materials with electrical and mechanical properties that change as the fabric changes shape. Meet the bike shorts of the future.

“The coating method operates at room temperature, requires no solvents, and does not compromise textile production speeds,” the Australian team reports. As such, the hybrid yarns are also pretty cheap to produce—a key requirement.

What makes the stuff really interesting is how it converts electricity into mechanical work. With an applied voltage, it’s possible to get the textile to contract by as much as 33 percent as it heats up. The material then relaxes as the voltage is removed and it cools down. This mechanical power output maxes out at around 1.28 kW/kg, which, the paper notes, is well beyond what’s offered by mammalian skeletal muscle. To demonstrate, the researchers used their new material to implement a knee brace, as below:

Another possible biomedical application is as a “lymph sleeve,” a compression sleeve used to treat lymphedema, a common side effect of cancer treatments.

“The lymph sleeve, for example, will be developed using lightweight actuating fabric that will detect swelling and then respond by ‘squeezing’ the arm to enhance lymph flow,” Javad Foroughi, the lead author of the new paper, told Physics World.  “We are also investigating the possibility of employing it in artificial-heart muscles for positive support of the right ventricle.”

Original story by Michael Byrne / Motherboard Vice.com

Carbon Nanotubes Could Provide the Military With Battery-Power in Textiles

Carbon Nanotubes Could Provide the Military With Battery-Power in Textiles

The carbon fibers can be spooled into strong, conductive thread. Like spider silk, it is stretchy and strong. Credit: Joseph Fuqua II/UC Creative Services
Carbon nanotubes could lead to clothing that can double as a battery, a discovery that could be particularly useful for the military.

A team from the University of Cincinnati—in a partnership with the Wright-Patterson Air force base—are working to take advantage of the properties of carbon nanotubes in developing new applications for soldiers in the field.

“The major challenge is translating these beautiful properties to take advantage of their strength, conductivity and heat resistance,” UC professor Vesselin Shanov, who co-directs UC’s Nanoworld Laboratories, said in a statement.

Graduate student Mark Haase has worked with Air Force researchers over the past year to find applications for carbon nanotubes using X-ray computer tomography to analyze samples.

“This pushes us to work in groups and to specialize,” Haase said in a statement. “These are the same dynamics we see in corporate research and industry. Engineering is a group activity these days so we can take advantage of that.”

The researchers used chemical vapor deposition to grow the carbon nanotubes on silicon wafers the size of a quarter under heat in a vacuum chamber.

“Each particle has a nucleation point,” Haase said. “Colloquially, we can call it a seed. Our carbon-containing gas is introduced into the reactor. When the carbon gas interacts with our ‘seed,’ it breaks down and re-forms on the surface. We let it grow until it reaches the size we want.”

UC’s Nanoworld Lab set a world record in 2007 by growing a nanotube that stretched nearly two centimeters, the longest carbon nanotube array produced in a lab at the time. The lab can currently create nanotubes that are substantially longer.

They were able to stretch the little fibrous square over an industrial spool in the lab to convert the sheet of carbon to a spun thread that can be woven into textiles.

“It’s exactly like a textile,” Shanov said. “We can assemble them like a machine thread and use them in applications ranging from sensors to track heavy metals in water or energy storage devices, including super capacitors and batteries.”

This ultimately could lead to a much lighter load for soldiers in battle.

“As much as one-third of the weight they carry is just batteries to power all of their equipment,” Haase said. “So even if we can shave a little off that, it’s a big advantage for them in the field.”

The study was published in Materials Research Express.
Full article by Kenny Walter – Digital Reporter @RandMagazine here.

eTextile Wristband Controls Small Household Appliances

Video: Watch a simple fabric wristband control small household appliances

[Image above] Credit: American Chemical Society, YouTube

We have come quite a long way from the TV remote control.

Technology has undoubtedly made our lives a lot easier in many respects. We’ve just about reached the point where we will be able to control nearly everything in our home remotely with the touch of a smartphone.

But for those little tasks inside the home, why bother with a smartphone? What if you wanted to use small appliances or your computer without messing with the on/off switches on each device?

Several researchers have already solved that problem by designing electronic textiles that could enable users to control a computer or small appliance by swiping a finger over fabric.

Although e-textiles are already on the market in many forms, the researchers wanted to improve upon existing technology. Most have “poor air permeability, can’t be laundered or are too costly or complex to mass-produce,” according to a news story from the American Chemical Society.

So the researchers developed a self-powered nanogenerator by screen-printing conductive carbon nanotube ink onto nylon fabric. And since this was a wearable device, of course, it needed to be washable. They combined polyurethane, a synthetic polymer, with the carbon nanotubes, adhering them to the fabric. After wrapping the entire device with silk and turning it into a wristband, the researchers connected the device to a computer and other small appliances to demonstrate how it could turn on and control appliances from several feet away.

And according to the researchers in the article, their e-textile is inexpensive to mass produce.

Besides making life easier for us able-bodied folks, the device could also help those with limited mobility or even disabled people better navigate their environment.

The paper, published in ACS Nano, is “Screen-Printed Washable Electronic Textiles as Self-Powered Touch/Gesture Tribo-Sensors for Intelligent Human–Machine Interaction” (DOI: 10.1021/acsnano.8b02477).

Original Article Published on June 20th, 2018 | By: Faye Oney

Watch the video below to see how the e-textile device can control small household appliances and a computer.

Electrical Interconnect Applications for Carbon Nanotubes in Military Aerospace Systems

Flexible, lightweight, and versatile CNTs are becoming a valuable material in conductor applications for the military and a host of other markets.

Carbon nanotubes are one of the most unique and interesting materials developed in the last decade. These products, widely known as CNTs, can be manufactured by various methods, but are most commonly made using chemical vapor deposition, a high-temperature manufacturing process used to create durable, solid, high-performance materials. The end result is a paper-like, ultra-thin sheet that can be further processed into a variety of forms suitable for a wide range of applications.

This material can become an electrically charged carbon sheet with some very special properties that are of great utility in conductor development. CNT sheets can be spun into fiber-like strands and twisted into various configurations that simulate copper stranding. An insulated jacket is then extruded on top of the carbon nanotube to create a wire. The resulting product is approximately one-eighth the weight of a typical copper conductor wire and has a strength-to-weight ratio 117 times that of steel. Additionally, because the material is fundamentally a type of plastic, it does not have the same fatigue characteristics as copper wire.

CNT technology can also be used to replace copper shields. By simply taking a thin CNT sheet and wrapping it around the wires to form a shield (see Figure 1), designers can achieve substantial weight savings over copper shields.

Challenges to CNT Adoption

Cost

CNT technology has had limited viability for use in many aerospace applications due to its higher initial costs. However, costs are coming down quickly. In the early development years of CNTs, the material cost around 500 times as much as copper. Today, the cost is closer to 10 times that of copper and, within the next five years, CNT is expected to command only a 20–30% price premium.

Electrical Conductivity

The electrical conductivity of CNT technology is vital to its overall success in electrical interconnect applications. In the early research and development phase, the resistivity of electrically charged CNTs was about 200 times that of copper. More recently, that value dropped down to only 20 times that of copper. Now samples from manufacturers are getting closer to 10 times the resistivity of copper. The current objective for leading developers of this technology is to bring it down to five times that of copper. If that happens, it will be a real game-changer.

EMI Protection

Lightweight shielding is very important to the defense industry, and CNTs show great promise here. Currently, CNT shields exhibit performance similar to copper at frequencies above 1GHz, but performance drops off significantly, especially at frequencies below 100Mhz. The weight savings over copper can be as much as 80%, though, so there is a trade-off that largely depends on an application’s EMI requirements. Solutions include using a combination of a CNT shield with a smaller-gauge copper shield, which could still reduce weight and perform reasonably well.

Termination

A lot of investigative work has been done on both crimping and soldering CNT material. To date, the crimp method shows the best results from a viability standpoint. Current mil spec standard tools and crimp contacts

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Connectors

Initial research into using CNTs to advance connector technology has focused on two primary areas: coaxial cables with RF connectors and mil standard 1553 data bus cables with dedicated discrete connectors. There are also efforts to evaluate CNTs with standard 38999 Series III connectors, as well as with miniature push-pull circular connectors commonly used in soldier systems. With the exception of the RF connectors, the preliminary results are encouraging, and show viability. However, this application may require some minor modifications to either the contacts or to the inserts. More research is still needed.

Manufacturers

The development of carbon nanotubes is truly a global effort led by several universities, including Rice University in Houston, that collaborate with CNT producers. Over the last few years, manufacturers in the US, Japan, and other countries have significantly scaled up production to help reduce costs to the point at which CNTs can become a viable multi-use product. These suppliers of CNT yarns and sheets are also working closely with several wire manufacturers to produce primary wire, cables, and RF coaxial cables.

Electrical Applications

One immediate application being evaluated by the defense industry is the replacement of copper-based 1553 database cables with CNT conductors and shields. The weight savings they offer can be upwards of several pounds, which is an especially significant advantage for space applications, as each pound of payload typically costs upwards of $10,000 to launch into space. Electrical testing has already been conducted to determine the signal integrity loss of CNT conductors and shields and has returned surprisingly good results, showing little signal loss degradation on lengths up to 10–15 feet, which will only improve as the conductivity of CNT materials continues to improve.

In addition to the space market, two helicopter manufacturers in the United States are conducting independent test studies to determine the viability of CNT materials for use in the rotary wing market.

A Bright Future for CNTs

CNT’s unique set of properties is helping the material find a place in applications across nearly every industry. CNTs are currently being employed in and evaluated for applications including optical power detectors, radar absorption, microelectronics, transistors, thermal management, solar panels, and even body armor. With this versatility, the future looks extremely bright for carbon-nanotube-based products.

Original story by by Tom Briere on June 20, 2017

Mil-Aero Industries Eye Carbon Nanotubes as They Target Cost Savings

Ultra-lightweight carbon nanotubes may replace copper wires.

Today’s aerospace and aircraft industries focus on size, weight, power, and cost (SWaP-C), and cost is now often figured for program or operational life, which may total thousands of dollars per pound. This gives tremendous impetus and justification to accept high-cost new technology to obtain weight savings.

Reducing F-35 by 20 Pounds Could Provide $230M Savings

Satellites have always paid extra to reduce weight since each payload pound may cost more than $5,000 to launch. Studies by the Center for Strategic and Budgetary Assessments (CSBA) show that the new F-35 has a $4,500 cost per pound over the aircraft’s operational program life

until 2070. (For comparison, the cost per pound for the F-22 is estimated at $3,500.) The F-35 has projected production of2,557 aircraft for the U.S. and nine for export customers scheduled through 2037. Therefore, a weight reduction of just 20lbs per plane could result in savings of $230,000,000! Even if this is off by 50%, the expected benefits already are driving new industry developments.

In addition to fighter aircraft, each ounce is also critical in future soldier wearables, UAVs, portable radars, vehicle communications, and other equipment to increase survivability, mission endurance, and success.

Interconnect weight savings are being obtained by incorporating higher contact density, composite materials, combinational multi-port connectors, and other approaches. However, a new technology involving carbon nanotubes (CNTs) is emerging and offers a lightweight alternative to copper wire and other conductive shielding materials. A carbon nanotube is produced as a layer of carbon atoms in a tubular configuration, in single- or multiple-walled versions.

CNTs are being mixed with polymers to create high-strength, lightweight composite materials. CNT fibers can be made into conductive sheets and tapes, which offer a myriad of potentials. Optimal performance may result from spinning CNT fibers into conductive threads (referred to as yarn) to potentially replace copper wires in harnesses, motor windings, and shields.

Another important gain is reliability. CNT fibers and yarn can withstand millions of bending cycles, while standard fiber/wire would have yielded many times. The minimum bending radius requirements of today’s cable is not applicable for CNT fibers and cables.

Market potentials for CNT technology are bringing new companies into the forefront. Nanocomp Technologies offers commercial CNT fibers created using a carbon vapor deposition (CVD) reactor and then formed into sheets or fibers that can be twisted into shields or primary conductors. Another supplier is Syscom Advanced Materials Inc., which provides a variety of metal-clad fibers.

DexMat Inc. in Houston produces CNT fiber using a wet acid process that draws multiple fibers that can be shaped into a shield or primary conductor, and future developments for  include flat tape. The company boasts a strong Ph.D. cadre from nearby Rice University where they have successfully fabricated coaxial cable inner and outer conductors by coating a solution of CNTs in chlorosulfonic acid to achieve a two-times better conductivity than seen previously. This may prove an attractive alternative to commercial coax cable using tin-coated-copper with comparable attenuation and greater mechanical durability with 97% reduced mass, according to the company.

Usually, the outer conductor is the heaviest portion of today’s cables. In coax, the outer conductor provides both signal transmission and electromagnetic shielding. While shielding does not require high conductivity in the outer conductor, signal loss (i.e., signal attenuation) through the transmission line is significantly affected by the conductivity and architecture of the outer conductor. The new solution-coated CNT outer conductors offer near-term application potentials. Several connector companies are reportedly studying termination techniques.

Carbon Nanotube Materials Provide Shielding

TE Connectivity has been working to use CNT materials for shielding and data transmission cables. In a paper presented at the 2012 IWCS Conference, Dr. Stefanie Harvey, senior manager for corporate strategy, reported that they had achieved greater than 50dB shielding effectiveness in the GHz range, and their “data transmission cables using a yarn format perform comparably to MIL-STD-1553.” In the January 5, 2016 issue of ASSEMBLY, Dr. Harvey reviewed how replacing the braid in RG-58 cable would reduce weight from 38.8 grams per meter (g/m) to 11.5g/m, while replacing the center conductor with CNT yarn would further reduce weight to 7.3g/m for a combined weight reduction of 80%.

Composites are used to replace heavy copper wire with metal plated aramid fibers for use in wire and cable EMI shielding. EMI shielding made with plated aramid fibers can reduce weight by as much as 80%, leading to major weight reduction depending on the size of the aircraft or satellite. Aramid fibers are a class of strong, heat-resistant synthetic fibers, the best known of which is DuPont™ Kevlar®, used in ballistic-rated body armor.

Carlisle Interconnect Technologies (formerly Micro-Coax Inc.) provides a unique weight-reducing EMI/RFI shielding solution using their proprietary high-strength ARACON® brand metal clad fibers. Ron Souders, technical director, Carlisle Interconnect Technologies, advises that, for typical applications, switching to ARACON allows a weight savings of 80% when compared to traditional metal braided or woven EMI shielding products. This offers the conductivity of an outer metal coating with the strength, light weight, and flexibility of aramid fiber.

*Note: DexMat also provides products for shielding applications not mentioned in this article.

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Ron Souders further explained that the specific gravity of aramid fiber is only 1.44g/cc, compared to copper at 8.9g/cc, and that, even with the addition of metal coatings, the specific gravity of ARACON fibers ranges from 3 – 5g/cc. The tensile strength (measured in kilopounds per square inch, or Ksi) of the aramid core (350Ksi) is from three to 10 times higher than that of traditional or high-strength copper cores, which typically span 35 to 95Ksi. Since ARACON fibers behave like a textile, they are far more flexible and compliant than metal.

Industry Standardization is Underway

The benefits offered by CNT fiber, whether as EMI/RFI shielding, signal or coaxial cable, or other new components, have prompted the Naval Air Systems Command (NAVAIR) in Patuxent River, Maryland, to sponsor the establishment of suitable “Military Specification for Conductive Carbon Conductors used in Aircraft Wiring,” eventually with QPL sources. The proposed formal qualification program should stabilize components and materials for future use.

CNT technology also was included in a recent multiple-day RF coordination meeting held in February by the Defense Logistics Agency (DLA) at the Defense Supply Center Columbus (DSCC). Suppliers of basic CNT materials, wire, cables, cable assembles, and signal and RF/microwave connectors are now working on both application-specific and generalized products to achieve the weight reduction and reliability benefits offered by CNT and other metallized fibers.

Original story by David Shaff – April 28, 2017