Category Archives: energy

Panasonic powers up a village in Myanmar with photovoltaics

This story reminded me of an account I read (when I was working in the city’s archives) of Vancouver’s (Canada) West End where residents were advised against going out at night after the sun set because there was no street lighting. And, in those days (19th century) the city was still somewhat forested with bears, foxes, coyotes, and other wild animals being a lot more common that they are today. (Vancouver is a big city but there are coyote warning signs on its beaches and residents of North Vancouver [a nearby municipality] occasionally have awakened to find bears in their backyards.)

Moving onto the true subject of this posting, Myanmar and power, a Sept. 22, 2016 news item on announced the presence of a new power grid in a village in Myanmar,

Panasonic Corporation provided the Power Supply Station; a stand-alone photovoltaic power package, to the village of Yin Ma Chaung, a Magway Region of the Republic of the Union of Myanmar. The Power Supply Station is installed as part of a CSR [Corporate social responsibility?] effort by the Sustainable Alternative Livelihood Development Project, supported by the Mae Fah Luang Foundation under Royal Patronage (MFL Foundation) of the Kingdom of Thailand. This project was rolled out in partnership with Mitsui & Co., Ltd as one of their CSR activities, and funded by donations to support the mission of the MFL Foundation’s activities.

A Sept. 22, 2016 Panasonic press release, which originated the news item, provides more detail about the power station,

Panasonic’s power supply station consists of solar modules and storage batteries, which enables energy to be created, stored and managed efficiently. The whole system is able to supply electricity to the entire village, relieving approximately 140 households in the non-electrified mountainous village by powering up electrical appliances and lights, which are essential and important in daily lives.

The presence of lightings [sic] in the village makes it possible for villagers to move around during the night, as prior to that; they were unable to do so since the area is inhabited by poisonous snakes. In addition, all the street lights have time-switch LED bulbs that could also make use of limited electricity, efficiently.

In Myanmar, its off-grid areas are said to be at the highest level among the ASEAN [Association of Southeast Asian Nations] countries, at approximately 68%1 across the nation. In its countryside, the number reaches to an estimate of 84%2 households being unconnected to electricity. To step up on its efforts, Panasonic also installed a refrigerator in the village’s meeting area to store anti-venom drugs. With a well-powered point, the meeting area has thus serves as a center for welfare, entertainment and other purposes.

The whole initiative aimed to provide additional electricity to surrounding villages as well; contributing to the entire Yenan Chuang Township.

Panasonic will continue to develop localized solutions in its bid to provide electricity to off-grid regions and improves the standard of living amongst communities, around the world.

The Power Supply Station is equipped with twelve Panasonic HIT solar modules and can output approximately 3 kW of electricity. It is also equipped with 24 storage batteries (approximately 17 kWh), enabling it to supply stored power.

Features of the Power Supply Station stand-alone photovoltaic power package

(1) Stable quality and performance achieved by production at the factory

The Power Supply Station was developed as a mass produced product to deliver stable quality overseas. The unit for this project was manufactured and its quality was controlled by our Thai subsidiary, Panasonic Eco Solutions Steel (Thailand) Co., Ltd., before delivery to Myanmar.

(2)Simple and quick assembly for portability and expansion

The station is designed to eliminate the need for on-site professional construction work, allowing an electrical contractor to easily and quickly install it.

(3) Utilization of proven Panasonic technologies

The station uses Panasonic HIT 3 solar modules to provide power efficiently, even in restricted spaces. The company’s newly developed power supply main unit acts as the energy management system to monitor the remaining electricity level of the lead-acid storage batteries and controls supply and demand, reducing deterioration of the batteries. This reduces the life-cycle cost and maintenance man-hours for the storage batteries.

There is a video which reminds you of what life could be like without electricity in the context of this Power Supply Station installation,

It’s nice to be reminded of how magical electricity and all its accoutrements are as so many of us with easy access take it all for granted.

A better buckypaper

‘Buckyballs’ is a slang term for buckminster fullerenes, spheres made up of a carbon atoms arranged in hexagons. It’s a tribute of sorts to Buckminster Fuller, an architect, designer, systems theorist and more, who developed a structure known as a geodesic dome which bears a remarkable resemblance to the carbon atom spheres known as buckyballs or buckminster fullerenes or fullerenes or C60 (for a carbon-based fullerene) for short. Carbon nanotubes are sometimes called buckytubes and there is a material known as buckypaper. A Sept. 20, 2016 news item on Nanowerk describes the latest work on buckypaper,

Researchers at the Masdar Institute of Science and Technology have developed a novel type of “buckypaper” – a thin film composed of carbon nanotubes – that has better thermal and electrical properties than most types of buckypaper previously developed. Researchers believe the innovative buckypaper could be used to create ultra-lightweight composite materials for numerous aerospace and energy applications, including advanced lightning strike protection on airplanes and more powerful lithium-ion batteries.

Masdar Institute’s Associate Professors of Mechanical and Materials Engineering Dr. Rashid Abu Al-Rub and Dr. Amal Al Ghaferi, along with Post-Doctoral Researcher Dr. Hammad Younes, developed the buckypaper with carbon nanostructures provided by global security, aerospace, and information technology company Lockheed Martin.

A Sept. 20, 2016 Masdar Institute (United Arab Emirates) press release, which originated the news item, describes the research in more detail,

The black, powdery flakes provided by Lockheed Martin’s Applied NanoStructured Solutions (ANS) contain hundreds of carbon nanotubes, which are one-atom thick sheets of graphene rolled into a tube that have extraordinary mechanical, electrical and thermal properties. Lockheed Martin’s carbon nanostructures are unique because the carbon nanotubes within each flake are all properly aligned, making them good conductors of heat and electricity.

“Lockheed Martin’s carbon nanostructures have many potential applications, but in its powdery form, it cannot be used. It has to be fabricated in a way that keeps the unique properties of the carbon nanotube,” explained Dr. Al Ghaferi. “The challenge we faced was to create something useful with the carbon nanotubes without losing any of their unique properties or disturbing the alignment.”

Dr. Younes said: “Each flake is a carbon nanostructure containing many aligned carbon nanotubes. The alignment of the tubes creates a path for conductivity, much like a wire, making the nanostructure an exceptionally good conductor of electricity.”

The Masdar Institute team mixed the carbon nanotubes with a polymer and their resulting buckypaper, which successfully maintained the alignment of the carbon nanotubes, demonstrated high thermal-electrical conductivity and superior mechanical properties.

“We have a secret recipe for self-aligning the carbon nanotubes within the buckypaper. This self-aligning is key in significantly enhancing the electrical, thermal and mechanical properties of our fabricated buckypapers,” explained Dr. Abu Al-Rub.

Despite their microscopic size – a carbon nanotube’s diameter is about 10,000 times smaller than a human hair – carbon nanotubes’ impact on technology has been huge. At the individual tube level, carbon nanotubes are 200 times stronger, five times more elastic, and five times more electrically conductive than steel.

Because of their extraordinary strength, thermal and electrical properties, and miniscule size, carbon nanotubes can be used in a number of applications, including ultra-thin energy storage devices, smaller and more efficient computer chips, photovoltaic solar cells, flexible electronics, cancer detection, and lightning-resistant coatings on airplanes.

According to a report by Global Industry Analysts Inc., the current global market for nanotubes is pegged at roughly US$5 billion and its market share is growing sharply, reflecting the rising sentiment worldwide in carbon nanotubes’ potential as a wonder technology.

Masdar Institute’s efforts to capitalize on this emerging technology have resulted in several cutting-edge carbon nanotube research projects, including an attempt to create carbon nanotube-strengthened concrete, super capacitors that can hold 50 times more charge, and a membrane that can bind organic micro-pollutants.

As the UAE moves towards a clean energy future, innovations in renewable energy storage systems and other sustainable technologies are crucial for the country’s successful transition, and researchers at Masdar Institute believe that carbon nanotubes will play a huge role in achieving energy sustainability.

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

Processing and property investigation of high-density carbon nanostructured papers with superior conductive and mechanical properties by Hammad Younesa, Rashid Abu Al-Ruba, Md. Mahfuzur Rahmana, Ahmed Dalaqa, Amal Al Ghaferia, Tushar Shahb. Diamond and Related Materials Volume 68, September 2016, Pages 109–117  DOI:

This paper is behind a paywall.

Using fish ‘biowaste’ for self-powered electronics

Researchers in India have found a way to make use of fish ‘biowaste’ according to a Sept. 6, 2016 news item on Nanowerk,

Large quantities of fish are consumed in India on a daily basis, which generates a huge amount of fish “biowaste” materials. In an attempt to do something positive with this biowaste, a team of researchers at Jadavpur University in Koltata, India explored recycling the fish byproducts into an energy harvester for self-powered electronics.

Caption: Waste fish scales (upper left corner) are used to fabricate flexible nanogenerator (lower left) that power up more than 50 blue LEDs (lower right). An enlarged microscopic view of a fish scale shows the well-aligned collagen fibrils (upper right). The possibility of making a fish scale transparent (middle) and rollable (extreme left lower corner) is also illustrated. Credit: Sujoy Kuman Ghosh and Dipankar Mandal/Jadavpur University

Caption: Waste fish scales (upper left corner) are used to fabricate flexible nanogenerator (lower left) that power up more than 50 blue LEDs (lower right). An enlarged microscopic view of a fish scale shows the well-aligned collagen fibrils (upper right). The possibility of making a fish scale transparent (middle) and rollable (extreme left lower corner) is also illustrated. Credit: Sujoy Kuman Ghosh and Dipankar Mandal/Jadavpur University

A Sept. 6, 2016 American Institute of Physics news release on EurekAlert, which originated the news item, describes the research in more detail,

The basic premise behind the researchers’ work is simple: Fish scales contain collagen fibers that possess a piezoelectric property, which means that an electric charge is generated in response to applying a mechanical stress. As the team reports this week in Applied Physics Letters, from AIP Publishing, they were able to harness this property to fabricate a bio-piezoelectric nanogenerator.

To do this, the researchers first “collected biowaste in the form of hard, raw fish scales from a fish processing market, and then used a demineralization process to make them transparent and flexible,” explained Dipankar Mandal, assistant professor, Organic Nano-Piezoelectric Device Laboratory, Department of Physics, at Jadavpur University.

The collagens within the processed fish scales serve as an active piezoelectric element.

“We were able to make a bio-piezoelectric nanogenerator — a.k.a. energy harvester — with electrodes on both sides, and then laminated it,” Mandal said.

While it’s well known that a single collagen nanofiber exhibits piezoelectricity, until now no one had attempted to focus on hierarchically organizing the collagen nanofibrils within the natural fish scales.

“We wanted to explore what happens to the piezoelectric yield when a bunch of collagen nanofibrils are hierarchically well aligned and self-assembled in the fish scales,” he added. “And we discovered that the piezoelectricity of the fish scale collagen is quite large (~5 pC/N), which we were able to confirm via direct measurement.”

Beyond that, the polarization-electric field hysteresis loop and resulting strain-electric field hysteresis loop — proof of a converse piezoelectric effect — caused by the “nonlinear” electrostriction effect backed up their findings.

The team’s work is the first known demonstration of the direct piezoelectric effect of fish scales from electricity generated by a bio-piezoelectric nanogenerator under mechanical stimuli — without the need for any post-electrical poling treatments.

“We’re well aware of the disadvantages of the post-processing treatments of piezoelectric materials,” Mandal noted.

To explore the fish scale collagen’s self-alignment phenomena, the researchers used near-edge X-ray absorption fine-structure spectroscopy, measured at the Raja Ramanna Centre for Advanced Technology in Indore, India.

Experimental and theoretical tests helped them clarify the energy scavenging performance of the bio-piezoelectric nanogenerator. It’s capable of scavenging several types of ambient mechanical energies — including body movements, machine and sound vibrations, and wind flow. Even repeatedly touching the bio-piezoelectric nanogenerator with a finger can turn on more than 50 blue LEDs.

“We expect our work to greatly impact the field of self-powered flexible electronics,” Mandal said. “To date, despite several extraordinary efforts, no one else has been able to make a biodegradable energy harvester in a cost-effective, single-step process.”

The group’s work could potentially be for use in transparent electronics, biocompatible and biodegradable electronics, edible electronics, self-powered implantable medical devices, surgeries, e-healthcare monitoring, as well as in vitro and in vivo diagnostics, apart from its myriad uses for portable electronics.

“In the future, our goal is to implant a bio-piezoelectric nanogenerator into a heart for pacemaker devices, where it will continuously generate power from heartbeats for the device’s operation,” Mandal said. “Then it will degrade when no longer needed. Since heart tissue is also composed of collagen, our bio-piezoelectric nanogenerator is expected to be very compatible with the heart.”

The group’s bio-piezoelectric nanogenerator may also help with targeted drug delivery, which is currently generating interest as a way of recovering in vivo cancer cells and also to stimulate different types of damaged tissues.

“So we expect our work to have enormous importance for next-generation implantable medical devices,” he added.

“Our end goal is to design and engineer sophisticated ingestible electronics composed of nontoxic materials that are useful for a wide range of diagnostic and therapeutic applications,” said Mandal.

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

High-performance bio-piezoelectric nanogenerator made with fish scale by Sujoy Kumar Ghosh and Dipankar Mandal. Appl. Phys. Lett. 109, 103701 (2016);

This paper appears to be open access.

Windows in Swiss trains are about to combine mobile reception and thermal insulation

A Sept. 2, 2016 news item on Nanowerk announces a whole new kind of train window,

EPFL [École polytechnique fédérale de Lausanne; Switzerland] researchers have developed a type of glass that offers excellent energy efficiency and lets mobile telephone signals through. And by teaming up with Swiss manufacturers, they have produced innovative windows. Railway company BLS is about to install them on some of its trains in order to improve energy efficiency.

An Aug. 26, 2016 EPFL press release, by Anne-Muriel Brouet, which originated the news item,

Train travel may be fast, but mobile connectivity onboard often lags behind. This is because the modern train car is a metal box that blocks out microwaves – in physics, this is called a Faraday cage. Even the windows contain an ultra-thin metal coating to improve thermal insulation. But EPFL researchers, working with manufacturing partners, have developed a new type of window that guarantees a comfortable temperature for passengers while at the same time letting mobile phone signals through.

In the rail industry, energy use is critical: around one third of the energy consumed by trains goes into providing heating and air conditioning in the train cars. And around 3% of this escapes through the windows. Double-glazed windows with an ultra-thin metal coating increase energy efficiency by a factor of four compared with untreated windows.

But the problem is that the metal sharply weakens the telecommunication signals. The solution that mobile phone operators and railway companies have used until now consists of placing signal boosters – or repeaters – in the trains. But they are expensive to install and maintain and have to be replaced regularly to keep pace with rapidly changing technologies. And each repeater consumes electricity.

A laser-scribed coating

Andreas Schüler, from EPFL’s Nanotechnology for Solar Energy Conversion Group, had another idea: “A metal coating that reflects heat waves (which are micrometric in size) but lets through both visible light (which is nanometric in size) and the electromagnetic waves of mobile phones (microwaves, which are centimetric in size).” But how is this done? “We breach the Faraday cage by modifying the metal coating with a special laser treatment. The windows then let the signals through,” said Schüler, a specialist in the optical and electronic properties of ultra-thin coatings.

To do this, a special structure is scribed into the metal coating with the aid of a high-precision laser. No more than 2.5% of the surface area of the metal coating is ablated by laser scribing. The resulting pattern is nearly invisible to the naked eye and does not affect the window’s insulating properties.

A manufacturing partnership pays off

Initial laboratory tests were extremely convincing. Several manufacturing partners were brought into the team in order to apply the method on a large scale. Thanks to the skills of glassmaker AGC Verres Industriels and the expertise of Class4Laser, prototype glass samples were produced and tested. “Measurements taken by experts from the University of Applied Sciences and Arts of Southern Switzerland (SUPSI) have demonstrated that this works,” said Schüler.

Energy savings for BLS

But the innovative glass needed to prove its mettle under real-life conditions. BLS was enthusiastic about testing the new windows as part of ongoing studies aimed at improving the energy efficiency of its trains. The first full-size windows were produced in the AGC Verres Industriels workshop and installed throughout a NINA-type self-propelled regional train.

The field tests met the partners’ expectations. Swisscom and SUPSI tested the efficacy of the new windows, both in BLS’s workshops and on the Bern-Thun train line. “Mobile reception is just as good in the train through laser-treated insulating glass as it is through ordinary glass,” said Schüler.

As a result, BLS has decided to install the new windows in most of its 36 NINA regional trains, replacing the old, non-insulating windows. Installation will begin in September 2016 as part of the company’s train modernization program. “Our commitment will help bring to market an innovative product designed to improve the energy efficiency of trains without compromising mobile reception for passengers,” said Quentin Sauvagnat, NINA fleet manager at BLS. Thanks to this product, those expensive signal repeaters will no longer be needed.

Are frequency-selective buildings next?

This proven and developed technology could be applied to buildings next. This is because, according to Schüler, “some glass buildings also act like Faraday cages. And as the internet of things continues to grow, there is a real interest in improving the properties of building materials that allow mobile signals through. More broadly, by making materials more frequency-selective, we could, for example, imagine a building that lets electromagnetic waves through but blocks Wi-Fi waves, thus enhancing corporate security.”

I have a friend who may find this train window innovation quite handy. As for frequency selective buildings, I imagine that would open up many possibilities for hackers.

Cooling the skin with plastic clothing

Rather that cooling or heating an entire room, why not cool or heat the person? Engineers at Stanford University (California, US) have developed a material that helps with half of that premise: cooling. From a Sept. 1, 2016 news item on ScienceDaily,

Stanford engineers have developed a low-cost, plastic-based textile that, if woven into clothing, could cool your body far more efficiently than is possible with the natural or synthetic fabrics in clothes we wear today.

Describing their work in Science, the researchers suggest that this new family of fabrics could become the basis for garments that keep people cool in hot climates without air conditioning.

“If you can cool the person rather than the building where they work or live, that will save energy,” said Yi Cui, an associate professor of materials science and engineering and of photon science at Stanford.

A Sept. 1, 2016 Stanford University news release (also on EurekAlert) by Tom Abate, which originated the news item, further explains the information in the video,

This new material works by allowing the body to discharge heat in two ways that would make the wearer feel nearly 4 degrees Fahrenheit cooler than if they wore cotton clothing.

The material cools by letting perspiration evaporate through the material, something ordinary fabrics already do. But the Stanford material provides a second, revolutionary cooling mechanism: allowing heat that the body emits as infrared radiation to pass through the plastic textile.

All objects, including our bodies, throw off heat in the form of infrared radiation, an invisible and benign wavelength of light. Blankets warm us by trapping infrared heat emissions close to the body. This thermal radiation escaping from our bodies is what makes us visible in the dark through night-vision goggles.

“Forty to 60 percent of our body heat is dissipated as infrared radiation when we are sitting in an office,” said Shanhui Fan, a professor of electrical engineering who specializes in photonics, which is the study of visible and invisible light. “But until now there has been little or no research on designing the thermal radiation characteristics of textiles.”

Super-powered kitchen wrap

To develop their cooling textile, the Stanford researchers blended nanotechnology, photonics and chemistry to give polyethylene – the clear, clingy plastic we use as kitchen wrap – a number of characteristics desirable in clothing material: It allows thermal radiation, air and water vapor to pass right through, and it is opaque to visible light.

The easiest attribute was allowing infrared radiation to pass through the material, because this is a characteristic of ordinary polyethylene food wrap. Of course, kitchen plastic is impervious to water and is see-through as well, rendering it useless as clothing.

The Stanford researchers tackled these deficiencies one at a time.

First, they found a variant of polyethylene commonly used in battery making that has a specific nanostructure that is opaque to visible light yet is transparent to infrared radiation, which could let body heat escape. This provided a base material that was opaque to visible light for the sake of modesty but thermally transparent for purposes of energy efficiency.

They then modified the industrial polyethylene by treating it with benign chemicals to enable water vapor molecules to evaporate through nanopores in the plastic, said postdoctoral scholar and team member Po-Chun Hsu, allowing the plastic to breathe like a natural fiber.

Making clothes

That success gave the researchers a single-sheet material that met their three basic criteria for a cooling fabric. To make this thin material more fabric-like, they created a three-ply version: two sheets of treated polyethylene separated by a cotton mesh for strength and thickness.

To test the cooling potential of their three-ply construct versus a cotton fabric of comparable thickness, they placed a small swatch of each material on a surface that was as warm as bare skin and measured how much heat each material trapped.

“Wearing anything traps some heat and makes the skin warmer,” Fan said. “If dissipating thermal radiation were our only concern, then it would be best to wear nothing.”

The comparison showed that the cotton fabric made the skin surface 3.6 F warmer than their cooling textile. The researchers said this difference means that a person dressed in their new material might feel less inclined to turn on a fan or air conditioner.

The researchers are continuing their work on several fronts, including adding more colors, textures and cloth-like characteristics to their material. Adapting a material already mass produced for the battery industry could make it easier to create products.

“If you want to make a textile, you have to be able to make huge volumes inexpensively,” Cui said.

Fan believes that this research opens up new avenues of inquiry to cool or heat things, passively, without the use of outside energy, by tuning materials to dissipate or trap infrared radiation.

“In hindsight, some of what we’ve done looks very simple, but it’s because few have really been looking at engineering the radiation characteristics of textiles,” he said.

Dexter Johnson (Nanoclast blog on the IEEE [Institute of Electrical and Electronics Engineers] website) has written a Sept. 2, 2016 posting where he provides more technical detail about this work,

The nanoPE [nanoporous polyethylene] material is able to achieve this release of the IR heat because of the size of the interconnected pores. The pores can range in size from 50 to 1000 nanometers. They’re therefore comparable in size to wavelengths of visible light, which allows the material to scatter that light. However, because the pores are much smaller than the wavelength of infrared light, the nanoPE is transparent to the IR.

It is this combination of blocking visible light and allowing IR to pass through that distinguishes the nanoPE material from regular polyethylene, which allows similar amounts of IR to pass through, but can only block 20 percent of the visible light compared to nanoPE’s 99 percent opacity.

The Stanford researchers were also able to improve on the water wicking capability of the nanoPE material by using a microneedle punching technique and coating the material with a water-repelling agent. The result is that perspiration can evaporate through the material unlike with regular polyethylene.

For those who wish to further pursue their interest, Dexter has a lively writing style and he provides more detail and insight in his posting.

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

Radiative human body cooling by nanoporous polyethylene textile by Po-Chun Hsu, Alex Y. Song, Peter B. Catrysse, Chong Liu, Yucan Peng, Jin Xie, Shanhui Fan, Yi Cui. Science  02 Sep 2016: Vol. 353, Issue 6303, pp. 1019-1023 DOI: 10.1126/science.aaf5471

This paper is open access.

Treating graphene with lasers for paper-based electronics

Engineers at Iowa State University have found a way they hope will make it easier to commercialize graphene. A Sept. 1, 2016 news item on describes the research,

The researchers in Jonathan Claussen’s lab at Iowa State University (who like to call themselves nanoengineers) have been looking for ways to use graphene and its amazing properties in their sensors and other technologies.

Graphene is a wonder material: The carbon honeycomb is just an atom thick. It’s great at conducting electricity and heat; it’s strong and stable. But researchers have struggled to move beyond tiny lab samples for studying its material properties to larger pieces for real-world applications.

Recent projects that used inkjet printers to print multi-layer graphene circuits and electrodes had the engineers thinking about using it for flexible, wearable and low-cost electronics. For example, “Could we make graphene at scales large enough for glucose sensors?” asked Suprem Das, an Iowa State postdoctoral research associate in mechanical engineering and an associate of the U.S. Department of Energy’s Ames Laboratory.

But there were problems with the existing technology. Once printed, the graphene had to be treated to improve electrical conductivity and device performance. That usually meant high temperatures or chemicals – both could degrade flexible or disposable printing surfaces such as plastic films or even paper.

Das and Claussen came up with the idea of using lasers to treat the graphene. Claussen, an Iowa State assistant professor of mechanical engineering and an Ames Laboratory associate, worked with Gary Cheng, an associate professor at Purdue University’s School of Industrial Engineering, to develop and test the idea.

A Sept. 1, 2016 Iowa State University news release (also on EurekAlert), which originated the news item, provides more detail about the intellectual property, as well as, the technology,

… They found treating inkjet-printed, multi-layer graphene electric circuits and electrodes with a pulsed-laser process improves electrical conductivity without damaging paper, polymers or other fragile printing surfaces.

“This creates a way to commercialize and scale-up the manufacturing of graphene,” Claussen said.

Two major grants are supporting the project and related research: a three-year grant from the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 11901762 and a three-year grant from the Roy J. Carver Charitable Trust. Iowa State’s College of Engineering and department of mechanical engineering are also supporting the research.

The Iowa State Research Foundation Inc. has filed for a patent on the technology.

“The breakthrough of this project is transforming the inkjet-printed graphene into a conductive material capable of being used in new applications,” Claussen said.

Those applications could include sensors with biological applications, energy storage systems, electrical conducting components and even paper-based electronics.

To make all that possible, the engineers developed computer-controlled laser technology that selectively irradiates inkjet-printed graphene oxide. The treatment removes ink binders and reduces graphene oxide to graphene – physically stitching together millions of tiny graphene flakes. The process makes electrical conductivity more than a thousand times better.

“The laser works with a rapid pulse of high-energy photons that do not destroy the graphene or the substrate,” Das said. “They heat locally. They bombard locally. They process locally.”

That localized, laser processing also changes the shape and structure of the printed graphene from a flat surface to one with raised, 3-D nanostructures. The engineers say the 3-D structures are like tiny petals rising from the surface. The rough and ridged structure increases the electrochemical reactivity of the graphene, making it useful for chemical and biological sensors.

All of that, according to Claussen’s team of nanoengineers, could move graphene to commercial applications.

“This work paves the way for not only paper-based electronics with graphene circuits,” the researchers wrote in their paper, “it enables the creation of low-cost and disposable graphene-based electrochemical electrodes for myriad applications including sensors, biosensors, fuel cells and (medical) devices.”

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

3D nanostructured inkjet printed graphene via UV-pulsed laser irradiation enables paper-based electronics and electrochemical devices by Suprem R. Das, Qiong Nian, Allison A. Cargill, John A. Hondred, Shaowei Ding, Mojib Saei, Gary J. Cheng, and   Jonathan C. Claussen. Nanoscale, 2016,8, 15870-15879 DOI: 10.1039/C6NR04310K First published online 12 Jul 2016

This paper is open access but you do need to have registered for your free account to access the material.

Next generation of power lines could be carbon nanotube-coated

This research was done at the Masdar Institute in Abu Dhabi of the United Arab Emirates. From a Sept. 1, 2016 news item on Nanowerk,

A Masdar Institute Assistant Professor may have brought engineers one step closer to developing the type of next-generation power lines needed to achieve sustainable and resilient electrical power grids.

Dr. Kumar Shanmugam, Assistant Professor of Materials and Mechanical Engineering, helped develop a novel coating made from carbon nanotubes that, when layered around an aluminum-conductor composite core (ACCC) transmission line, reduces the line’s operating temperature and significantly improves its overall transmission efficiency.

An Aug. 29, 2016 Masdar Institute news release by Erica Solomon, which originated the news item, provides more detail,

The coating is made from carbon nanostructures (CNS) – which are bundles of aligned carbon nanotubes that have exceptional mechanical and electrical properties – provided by the project’s sponsor, Lockheed Martin. The second component of the coating is an epoxy resin, which is the thick material used to protect things like appliances and electronics from damage.  Together, the CNS and epoxy resin help prevent power lines from overheating, increases their current carrying capacity (the amount of current that can flow through a transmission line), while also protecting them from damages associated with lightning strikes, ice and other environmental impacts.

The researchers found that by replacing traditional steel-core transmission lines with ACCC cables layered with a CNS-epoxy coating (referred to in the study as ACCC-CNS lines), the amount of aluminum used in an ACCC cable can be reduced by 25%, making the cable significantly lighter and cheaper to produce. The span length of a transmission line can also increase by 30%, which will make it easier to transmit electricity across longer distances while the amount of current the line can carry can increase by 40%.

“The coating helps to dissipate the heat generated in the conductor more efficiently through radiation and convection, thereby preventing the cable from overheating and enabling it to carry more current farther distances,” Dr. Kumar explained.

Ultimately, the purpose of the coating is to effectively eliminate the transmission line losses. Each year, anywhere from 5% to over 10% of the overall power generated in a power plant is lost in transmission and distribution lines. Most of this electrical energy is lost in the form of heat; as current runs through a conductor (the transmission line), the conductor heats up because it resists the flow of electrons to some extent – a phenomenon known as resistive Joule heating. Resistive Joule heating causes the energy that was moving the electrons forward to change into heat energy, which means some of the generated power gets converted into heat and lost to the surrounding environment instead of getting to its intended destination (like our homes and offices).

In addition to wasting energy, resistive Joule heating can lead to overheating, which can trigger a transmission line to “sag”, or physically droop low to the ground. Sagging power lines in turn can have catastrophic effects, including short circuits and power outages.

Efforts to reduce the problem of resistive heating and energy loss in power lines have led to significant improvements in transmission line technologies. For example, in 2002 ACCC transmission cables – which feature a carbon and glass-fiber reinforced composite core wrapped in aluminum conductor wires – were invented. The ACCC conductors are lighter and more heat-resistant than traditional steel-core cables, which means they can carry more current without overheating or sagging. Today, it is estimated that over 200 power and distribution networks use ACCC transmission cables.

While the advent of composite core cables marks the first major turning point in the development of energy-efficient transmission lines, Dr. Kumar’s CNS-epoxy coating may be the second significant advancement in the evolution of sustainable power lines.

The CNS-epoxy coating works by keeping the cable’s operating temperatures low. It does this by dissipating, any generated heat away from the conductor efficiently, thereby preventing further increase in temperature of the line and avoiding the trickle-effect that often leads to overheating.

The coating is layered twice in the ACCC cable – an outer layer, which dissipates the heat and protects the cable from environmental factors like lightning strikes and foreign object impact; and an inner layer, which protects the composite core from damage caused by stray radio frequency radiation generated by the electromagnetic pulse emanating from high electric current carrying aluminum conductor

The research team utilized a multi-physics modeling framework to analyze how the CNS-epoxy coating would influence the performance of ACCC transmission line. After fabricating the coating, they characterized it, which is a critical step to determine its mechanical, thermal and electrical properties. These properties were then used in the computational and theoretical models to evaluate and predict the coating’s performance. Finally, a design tool was developed and used to find the optimal combination of parameters (core diameter, span distance and sag) needed to reduce the cable’s weight, sag, and operating temperature while increasing its span distance and current carrying capacity.

Dr. Kumar’s innovative transmission line technology research comes at a pivotal time, when countries all over the world, including the UAE, are seeking ways to reduce their carbon footprint in a concerted effort to mitigate global climate change. Turning to energy-efficient power lines that waste less power and in turn produce less carbon dioxide emissions will be an obvious choice for nations devoted to greater sustainability.

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

High-Ampacity Overhead Power Lines With Carbon Nanostructure–Epoxy Composites by V. S. N. Ranjith Kumar, S. Kumar, G. Pal, and Tushar Shah. J. Eng. Mater. Technol 138(4), 041018 (Aug 09, 2016) (9 pages) Paper No: MATS-15-1217; doi: 10.1115/1.4034095

This paper is behind a paywall.

Nanoavalanches in glass

An Aug. 24, 2016 news item on Nanowerk takes a rather roundabout way to describe some new findings about glass (Note: A link has been removed),

The main purpose of McLaren’s exchange study in Marburg was to learn more about a complex process involving transformations in glass that occur under intense electrical and thermal conditions. New understanding of these mechanisms could lead the way to more energy-efficient glass manufacturing, and even glass supercapacitors that leapfrog the performance of batteries now used for electric cars and solar energy.

“This technology is relevant to companies seeking the next wave of portable, reliable energy,” said Himanshu Jain, McLaren’s advisor and the T. L. Diamond Distinguished Chair in Materials Science and Engineering at Lehigh and director of its International Materials Institute for New Functionality in Glass. “A breakthrough in the use of glass for power storage could unleash a torrent of innovation in the transportation and energy sectors, and even support efforts to curb global warming.”

As part of his doctoral research, McLaren discovered that applying a direct current field across glass reduced its melting temperature. In their experiments, they placed a block of glass between a cathode and anode, and then exerted steady pressure on the glass while gradually heating it. McLaren and Jain, together with colleagues at the University of Colorado, published their discovery in Applied Physics Letters (“Electric field-induced softening of alkali silicate glasses”).

The implications for the finding were intriguing. In addition to making glass formulation viable at lower temperatures and reducing energy needs, designers using electrical current in glass manufacturing would have a tool to make precise manipulations not possible with heat alone.

“You could make a mask for the glass, for example, and apply an electrical field on a micron scale,” said Jain. “This would allow you to deform the glass with high precision, and soften it in a far more selective way than you could with heat, which gets distributed throughout the glass.”

Though McLaren and Jain had isolated the phenomenon and determined how to dial up the variables for optimal results, they did not yet fully understand the mechanisms behind it. McLaren and Jain had been following the work of Dr. Bernard Roling at the University of Marburg, who had discovered some remarkable characteristics of glass using electro-thermal poling, a technique that employs both temperature manipulation and electrical current to create a charge in normally inert glass. The process imparts useful optical and even bioactive qualities to glass.

Roling invited McLaren to spend a semester at Marburg to analyze the behavior of glass under electro-thermal poling, to see if it would reveal more about the fundamental science underlying what McLaren and Jain had observed in their Lehigh lab.

An Aug. 22, 2016 Lehigh University news release by Chris Quirk, which originated the news item, describes the latest work,

McLaren’s work in Marburg revealed a two-step process in which a thin sliver of the glass nearest the anode, called a depletion layer, becomes much more resistant to electrical current than the rest of the glass as alkali ions in the glass migrate away. This is followed by a catastrophic change in the layer, known as dielectric breakdown, which dramatically increases its conductivity. McLaren likens the process of dielectric breakdown to a high-speed avalanche, and uses spectroscopic analysis with electro-thermal poling as a way to see what is happening in slow motion.

“The results in Germany gave us a very good model for what is going on in the electric field-induced softening that we did here. It told us about the start conditions for where dielectric breakdown can begin,” said McLaren.

“Charlie’s work in Marburg has helped us see the kinetics of the process,” Jain said. “We could see it happening abruptly in our experiments here at Lehigh, but we now have a way to separate out what occurs specifically with the depletion layer.”

“The Marburg trip was incredibly useful professionally and enlightening personally,” said McLaren. “Scientifically, it’s always good to see your work from another vantage point, and see how other research groups interpret data or perform experiments. The group in Marburg was extremely hard-working, which I loved, and they were very supportive of each other. If someone submitted a paper, the whole group would have a barbecue to celebrate, and they always gave each other feedback on their work. Sometimes it was brutally honest––they didn’t hold back––but they were things you needed to hear.”

“Working in Marburg also showed me how to interact with a completely different group of people. “You see differences in your own culture best when you have the chance to see other cultures close up. It’s always a fresh perspective.”

Here are links and citations for both the papers mentioned. The first link is for the most recent paper and second link is for the earlier work,

Depletion Layer Formation in Alkali Silicate Glasses by
Electro-Thermal Poling by C. McLaren, M. Balabajew, M. Gellert, B. Roling, and H. Jain. Journal of The Electrochemical Society, 163 (9) H809-H817 (2016) H809 DOI: 10.1149/2.0881609jes Published July 19, 2016

Electric field-induced softening of alkali silicate glasses by C. McLaren, W. Heffner, R. Tessarollo, R. Raj, and H. Jain. Appl. Phys. Lett. 107, 184101 (2015); Published online 03 November 2015

The most recent paper (first link) appears to be open access; the earlier paper (second link) is behind a paywall.

New electrochromic material for ‘smart’ windows

Given that it’s summer, I seem to be increasingly obsessed with windows that help control the heat from the sun. So, this Aug. 22, 2016 news item on ScienceDaily hit my sweet spot,

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have invented a new flexible smart window material that, when incorporated into windows, sunroofs, or even curved glass surfaces, will have the ability to control both heat and light from the sun. …

Delia Milliron, an associate professor in the McKetta Department of Chemical Engineering, and her team’s advancement is a new low-temperature process for coating the new smart material on plastic, which makes it easier and cheaper to apply than conventional coatings made directly on the glass itself. The team demonstrated a flexible electrochromic device, which means a small electric charge (about 4 volts) can lighten or darken the material and control the transmission of heat-producing, near-infrared radiation. Such smart windows are aimed at saving on cooling and heating bills for homes and businesses.

An Aug. 22, 2016 University of Texas at Austin news release (also on EurekAlert), which originated the news item, describes the international team behind this research and offers more details about the research itself,

The research team is an international collaboration, including scientists at the European Synchrotron Radiation Facility and CNRS in France, and Ikerbasque in Spain. Researchers at UT Austin’s College of Natural Sciences provided key theoretical work.

Milliron and her team’s low-temperature process generates a material with a unique nanostructure, which doubles the efficiency of the coloration process compared with a coating produced by a conventional high-temperature process. It can switch between clear and tinted more quickly, using less power.

The new electrochromic material, like its high-temperature processed counterpart, has an amorphous structure, meaning the atoms lack any long-range organization as would be found in a crystal. However, the new process yields a unique local arrangement of the atoms in a linear, chain-like structure. Whereas conventional amorphous materials produced at high temperature have a denser three-dimensionally bonded structure, the researchers’ new linearly structured material, made of chemically condensed niobium oxide, allows ions to flow in and out more freely. As a result, it is twice as energy efficient as the conventionally processed smart window material.

At the heart of the team’s study is their rare insight into the atomic-scale structure of the amorphous materials, whose disordered structures are difficult to characterize. Because there are few techniques for characterizing the atomic-scale structure sufficiently enough to understand properties, it has been difficult to engineer amorphous materials to enhance their performance.

“There’s relatively little insight into amorphous materials and how their properties are impacted by local structure,” Milliron said. “But, we were able to characterize with enough specificity what the local arrangement of the atoms is, so that it sheds light on the differences in properties in a rational way.”

Graeme Henkelman, a co-author on the paper and chemistry professor in UT Austin’s College of Natural Sciences, explains that determining the atomic structure for amorphous materials is far more difficult than for crystalline materials, which have an ordered structure. In this case, the researchers were able to use a combination of techniques and measurements to determine an atomic structure that is consistent in both experiment and theory.

“Such collaborative efforts that combine complementary techniques are, in my view, the key to the rational design of new materials,” Henkelman said.

Milliron believes the knowledge gained here could inspire deliberate engineering of amorphous materials for other applications such as supercapacitors that store and release electrical energy rapidly and efficiently.

The Milliron lab’s next challenge is to develop a flexible material using their low-temperature process that meets or exceeds the best performance of electrochromic materials made by conventional high-temperature processing.

“We want to see if we can marry the best performance with this new low-temperature processing strategy,” she said.

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

Linear topology in amorphous metal oxide electrochromic networks obtained via low-temperature solution processing by Anna Llordés, Yang Wang, Alejandro Fernandez-Martinez, Penghao Xiao, Tom Lee, Agnieszka Poulain, Omid Zandi, Camila A. Saez Cabezas, Graeme Henkelman, & Delia J. Milliron. Nature Materials (2016)  doi:10.1038/nmat4734 Published online 22 August 2016

This paper is behind a paywall.

Transparent wood more efficient than glass in windows?

University of Maryland researchers are suggesting that transparent wood could be more energy efficient than glass. An Aug. 16, 2016 news item on ScienceDaily describes the research,

Engineers at the A. James Clark School of Engineering at the University of Maryland (UMD) demonstrate in a new study that windows made of transparent wood could provide more even and consistent natural lighting and better energy efficiency than glass.

An Aug. 16, 2016 University of Maryland news release (also on EurekAlert) which originated the news item, explains further,

In a paper just published in the peer-reviewed journal Advanced Energy Materials, the team, headed by Liangbing Hu of UMD’s Department of Materials Science and Engineering and the Energy Research Center lay out research showing that their transparent wood provides better thermal insulation and lets in nearly as much light as glass, while eliminating glare and providing uniform and consistent indoor lighting. The findings advance earlier published work on their development of transparent wood.

The transparent wood lets through just a little bit less light than glass, but a lot less heat, said Tian Li, the lead author of the new study. “It is very transparent, but still allows for a little bit of privacy because it is not completely see-through. We also learned that the channels in the wood transmit light with wavelengths around the range of the wavelengths of visible light, but that it blocks the wavelengths that carry mostly heat,” said Li.

The team’s findings were derived, in part, from tests on tiny model house with a transparent wood panel in the ceiling that the team built. The tests showed that the light was more evenly distributed around a space with a transparent wood roof than a glass roof.

The channels in the wood direct visible light straight through the material, but the cell structure that still remains bounces the light around just a little bit, a property called haze. This means the light does not shine directly into your eyes, making it more comfortable to look at. The team photographed the transparent wood’s cell structure in the University of Maryland’s Advanced Imaging and Microscopy (AIM) Lab.

Transparent wood still has all the cell structures that comprised the original piece of wood. The wood is cut against the grain, so that the channels that drew water and nutrients up from the roots lie along the shortest dimension of the window. The new transparent wood uses theses natural channels in wood to guide the sunlight through the wood.

As the sun passes over a house with glass windows, the angle at which light shines through the glass changes as the sun moves. With windows or panels made of transparent wood instead of glass, as the sun moves across the sky, the channels in the wood direct the sunlight in the same way every time.

“This means your cat would not have to get up out of its nice patch of sunlight every few minutes and move over,” Li said. “The sunlight would stay in the same place. Also, the room would be more equally lighted at all times.”

Working with transparent wood is similar to working with natural wood, the researchers said. However, their transparent wood is waterproof due to its polymer component. It also is much less breakable than glass because the cell structure inside resists shattering.

The research team has recently patented their process for making transparent wood. The process starts with bleaching from the wood all of the lignin, which is a component in the wood that makes it both brown and strong. The wood is then soaked in epoxy, which adds strength back in and also makes the wood clearer. The team has used tiny squares of linden wood about 2 cm x 2 cm, but the wood can be any size, the researchers said.

Here’s an image illustrating the research,

Caption: This is a wood composite as an energy efficient building material: Guided sunlight transmission and effective thermal insulation. Credit: University of Maryland and Advanced Energy Materials

Caption: This is a wood composite as an energy efficient building material: Guided sunlight transmission and effective thermal insulation. Credit: University of Maryland and Advanced Energy Materials

I have written about transparent wood twice before. There’s this April 1, 2016 posting about the work at the KTH Institute (Sweden) and a May 11, 2016 posting about some earlier work at the University of Maryland.

Here’s a link and a citation for the latest from the University of Maryland,

Wood Composite as an Energy Efficient Building Material: Guided Sunlight Transmittance and Effective Thermal Insulation by Tian Li, Mingwei Zhu, Zhi Yang, Jianwei Song, Jiaqi Dai, Yonggang Yao, Wei Luo, Glenn Pastel, Bao Yang, and Liangbing Hu. Advanced Energy Materials Version of Record online: 11 AUG 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.