Category Archives: Energy Storage

by David Hwang and Jurron Bradley, Lux Research

April 1, 2010 – Since pioneers Showa Denko and Hyperion Catalysis first started producing multi-walled carbon nanotubes (MWNTs) in 1983, dozens of companies have entered the fray, looking to claim a share of a potentially massive market. However, market adoption has taken much longer than many expected, ultimately driving companies without proper financial backing into the red. Despite the gloom, MWNT suppliers aren’t an endangered species, as more than 35 commercial suppliers are still active.

Across the industry, producers are increasing capacity with hopes of lower costs and greater market adoption. The ongoing game of one-upsmanship is pushing market leaders to increase their capacities by more than four-fold in order to prevent becoming priced out of the market by their competitors. In 2008, global MWNT production capacity totaled just 423 tons, but today it weighs-in at 1,334 tons, a whopping 215% increase. Moreover, once current capacity expansions are completed (likely in 2010 and 2011), total capacity will swell to 2,389, a 416% increase over 2008 levels. Note that some plans to scale-up are confidential and thus are not included in the table below.

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Figure 1. Key MWNT suppliers. (CCVD = catalytic chemical vapor deposition; SME = small or medium-sized enterprise)

Looking closer, production capacity is owned disproportionately by the largest five suppliers: Showa Denko, CNano Technology, Arkema, Nanocyl, and Bayer MaterialScience. CNano Technology completed construction of its 500 ton production facility in June 2009, and Showa Denko finished building a 400-ton plant in March 2010, bringing its total up to 500 tons as well, making them the two largest suppliers. The other three suppliers — Arkema, Nanocyl, and Bayer MaterialScience — are scheduled to bring multi-hundred-ton facilities online in late 2010 and early 2011. Together, the five largest suppliers operated 54% of the world’s total production capacity in 2008 — and after completing the planned scale-ups, they will operate over 86% of the global production capacity in 2011. The massive scale-up and resulting cost reduction will further cement their dominance over second- and third-tier suppliers, making it even harder for the smaller producers to compete.

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Figure 2. Announced MWNT production capacity.

Don’t fall for the hype, however — because the market isn’t expanding at the same rapid scale-up rate. In fact, with a few exceptions, average utilization of production capacity per company is likely in the low double-digit percent. Specifically, we estimate that producers sold only 124 tons of MWNT in 2008, meaning a 30% utilization of capacity globally. With the producers undergoing such massive scale-ups, the amount of idle capacity is set to expand even further in the near-term, as sales grew approximately 35% in 2009, but production capacity more than doubled. This oversupply situation will likely persist at least through 2015.

While the extra capacity will not equate to additional revenue immediately, it will help MWNT’s long-term prospects. For one, scale-up to date has driven prices down from the dollars/gram range to $100/kg today, and producers ultimately hope to achieve $50/kg. When MWNTs were dollars/gram, industries turned their backs — but now that the economics for using MWNTs are quickly becoming favorable (especially in composite applications) they’re showing a renewed sense of interest. Additionally, further price reductions will help MWNTs expand out of small-volume niche applications like fishing poles and into larger and more cost-sensitive markets like car body panels. More broadly, producers are pushing their products into the automotive, aerospace, electronics, wind power, and energy storage industries — all of which will to drive demand for the next decade.

Biographies

David Hwang received a BSE in Bioengineering from the University of Pennsylvania and is research associate at Lux Research Inc., e-mail [email protected].

Jurron Bradley received his Ph.D in chemical engineering from the Georgia Institute of Technology and is senior analyst at Lux Research Inc.

This article was originally published by RenewableEnergyWorld.com and was reprinted by permission.

by Jennifer Kho, contributor, RenewableEnergyWorld.com

March 24, 2010 – When A123Systems saw its shares jump more than 50% in a successful Nasdaq debut back in September, some industry insiders expected it would be the first of a bevy of big energy-storage headlines. Instead, energy storage seems to have fallen out of the limelight, getting nothing near as much hype as Bloom Energy, a fuel-cell company focused on electricity generation instead of energy storage, generated when it launched last month.

But a series of recent small announcements suggest that energy-storage technologies are quietly making progress toward commercialization nonetheless. "There seems to be a lot more buzz in the last few months, and what’s interesting is it’s not all on the automotive side," said Sara Bradford, a principal consultant for global research firm Frost & Sullivan. While automobiles remain a key area for new energy-storage technologies, she’s seeing a "spillover effect" as research and investment spreads into other areas, including grid applications for utilities and nonautomotive transportation.

Some examples? In February, Valence Technology signed a $45 million deal to supply its lithium-ion battery systems for a new line of hybrid-electric yachts, sailboats and motorboats from Beneteau Group. And International Battery, another lithium-ion rechargeable battery manufacturer, announced it was selected to supply battery systems for an American Electric Power smart-grid demonstration project in Ohio.

The community energy storage part of the project, which is being developed by S&C Electric Company, is intended help stabilize the grid and provide backup power, potentially enabling plug-in electric vehicles and a higher percentage of intermittent renewable-energy sources, such as solar and wind power.

In January, battery maker GS Battery teamed up with screen-printed solar-cell manufacturer Suniva to develop solar-power systems with batteries that can store the energy for times of peak demand. And Ice Energy — which reduces peak electricity demand from air conditioners in the middle of the day by making ice at night, when demand is low and surplus electricity is available, and using it to help cool air conditioning refrigerant when temperatures are high — signed a deal to sell its devices to the 11 municipal utilities represented by the Southern California Public Power Authority.

While many of the announcements have represented only small steps — such as pilot projects or an entrance into niche markets — they show that a number of technologies are on the right track, and some are ready to go, she said. "Exciting things are happening that set the stage to really make [commercialization] happen short-term," Bradford said. "These announcements are certainly steps in the right direction to get these technologies ready for electric vehicles and the grid."

Electric vehicles and grid storage represent huge potential markets for new energy-storage technologies. As startups Tesla Motors and Fisker Automotive work to advance electric sports cars, companies such as General Motors Corp., Ford Motor Co., and Volkswagen are rushing to come out with plug-in hybrids. And as utilities work to meet state renewable-energy goals and add more solar and wind power to their portfolios, energy storage to help smooth out the intermittent power from those sources is becoming ever more critical.

Roadblocks ahead

Of course, energy storage technologies have some big obstacles to overcome before they’ll be commercially viable for those applications, Bradford said. First of all, they’re too expensive, and companies are working to cut costs. Car battery systems also need high power density, as automakers want batteries to deliver a long electric range with as little size and weight as possible, and — given the high density — technology that ensures they that won’t catch fire. Safety also is a big issue for backup power batteries, especially those intended for homes, Bradford said.

And while both electric vehicle and clean-energy markets have been spurred by government initiatives and policies, both the auto industry and the energy industry are notoriously slow-moving. In general, companies with multiple applications will be more likely to have the foundation they need to survive the wait to the electric vehicle and grid markets, Bradford said. "Obviously, the Holy Grail is to be in the automotive or grid market for this technology, but the reality is there needs to be niche applications to build that momentum to those big fish," she said.

Why are we seeing all this activity now? For one thing, Bradford thinks we may be seeing a delayed effect from the A123 IPO. "It didn’t happen right away — 2009 was a rocky year for the industry, with some setbacks in orders coming in and the economic downturn — but now I’m seeing some new interest," she said. "Certainly I feel from the research that we’ve seen and the market movement that this [sector] may emerge more quickly than others when the economy recovers."

The stimulus package also played a big role in raising interest in energy-storage technology, setting aside $2 billion in advanced battery manufacturing grants and up to $25 billion in loans for advanced vehicles, including related energy-storage technologies. Last year, Bradford said that the U.S. battery industry was "humming with revived confidence" as a result of the stimulus package.

Even though the loan guarantees have rolled out more slowly than expected, the government funding has clearly had an effect. For example, when A123 won a $249 million manufacturing grant from the U.S. Department of Energy a month before its initial public offering last year, it "was pretty clear [the grant] helped get investors excited about the company," said Sheeraz Haji, president of the Cleantech Group. "Private capital is following public capital." Venture-capital investment in energy storage grew 23% globally in 2009 to $472 million, according to the group.

With all the government and venture-capital attention, you can expect to see more energy-storage announcements coming soon. It remains to be seen whether the announcements will result in real products that can help spur electric vehicles and more renewable energy on the grid, but Bradford said that several companies are now finishing up their evaluation period — meaning that it should soon become clear whether their technologies are ready to address these markets or not.

One good sign is that a few companies are starting to see revenues, she said, pointing to Valence’s commercial deal. Bradford expects to see more energy-storage technologies to hit the market in the next 12 to 18 months.

Freelancer Jennifer Kho has been covering green technology since 2004, when she was a reporter at Red Herring magazine. She has more than nine years of reporting experience, most recently serving as the editor of Greentech Media. Her stories have appeared in such publications as The Wall Street Journal, the Los Angeles Times, BusinessWeek.com, CNN.com, Earth2Tech, Cleantechnica, MIT’s Technology Review, and TheStreet.com.

(March 24, 2010) — Peter Harrop, Ph.D., chairman, IDTechEx, describes advances in the manufacturing of stretchable electronics, printed medical electronics applications, printed batteries, energy harvesters, edible electronics, and more.

For 40 years, integrated circuits (ICs) have integrated little more than transistors, diodes and sensors onto one piece of material. Now, with innovative package design, there are more integrated circuits arriving where most electrical and electronic components are co-deposited on flexible substrates. Those flexible substrates are key, because this new electronics will be affordable and desirable on everything from apparel to human skin and electrical and consumer packaged goods, where surfaces are only rarely flat.

Savvy designers, seeking to use the new electronics to create blockbuster products, think of the flexible substrate as part of functioning of the product. For example, there are flexible films that emit and detect ultrasound, act as loudspeakers, or change shape under an electrical field. The latter use electroactive polymer film and the recent purchase of Artificial Muscle Inc AMI by Bayer Material Science is a nice reminder that there are plenty of exits for venture capitalists backing these new printed electronics companies.

Stretchable electronics

AMI polymer films, with printed stretchable electrodes, are used in the development, design and manufacture of actuators and sensing components. They offer significant advantages over traditional technologies used in this area. They provide touchscreen panels in consumer electronics with "awareness through touch" by creating authentic tactile feedback, just like a conventional keyboard. This innovative technology has significant application potential, particularly for electronic devices like smart phones, gaming controllers and touchpads. AMI initially targeted products for a range of applications including valves, pumps, positioners, power generation, snake-like, self-aiming camera lenses and sensors. With the emergent need for haptics in consumer electronics, particularly in touchscreens, AMI used EPAM to create the Reflex brand of haptic actuators. These products are targeted at a wide range of consumer electronics including smartphones and other portable electronics, computer peripherals, gaming controllers and touchpads.

Meanwhile, MC10 Inc, a company formed to commercialize stretchable electronics, has recently made a licensing agreement with the University of Illinois at Urbana-Champaign. According to the terms of the agreement, MC10 Inc. will gain access to technology contained in patents dealing with stretchable silicon technology from Professor John Rogers’ laboratory. The venture-backed startup is currently developing processes and applications that enable high performance electronics to be placed in novel environments and form factors. MC10’s approach transforms traditionally rigid, brittle semiconductors into flexible, stretchable electronics while retaining excellent electrical performance. Stretchable silicon allows for a degree of design freedom capable of expanding the functionality of existing products whilst providing a platform on which new microelectronic-enabled applications can be developed.

Surgery

In a completely different approach, the electroactive devices of Artificial Muscle AB in Sweden, with stretchable printed electrodes, make surgeons’ tools snake through the human body. Researchers at Purdue University have created a magnetic "ferropaper" that might be used to make low-cost "micromotors" for surgical instruments, tiny tweezers to study cells and miniature speakers. Control and monitoring electronics and electrics can be printed onto this new smart paper. The material is made by impregnating ordinary paper – even newsprint – with a mixture of mineral oil and "magnetic nanoparticles" of iron oxide. The nanoparticle-laden paper can then be moved using a magnetic field.

"Paper is a porous matrix, so you can load a lot of this material into it," said Babak Ziaie, a professor of electrical and computer engineering and biomedical engineering.
 
The new technique represents a low-cost way to make small stereo speakers, miniature robots or motors for a variety of potential applications, including tweezers to manipulate cells and flexible fingers for minimally invasive surgery.
 
"Because paper is very soft it won’t damage cells or tissue," Ziaie said. "It is very inexpensive to make. You put a droplet on a piece of paper, and that is your actuator, or motor."

cPaper

Kimberley Clark is one of the latest to announce a smart substrate suitable for printed electronics. Its cPaper is paper impregnated with carbon rather than the more expensive carbon nanotubes and  it can be used as heating elements, electrodes in printed supercapacitors and super-batteries and in many other applications.

Organic impregnated conductive paper

In a different approach, the University of Uppsala in Sweden may be on the way to improved printed batteries. It is developing a novel nanostructured high-surface area electrode material for energy storage applications composed of cellulose fibers of algal origin individually coated with a 50 nm thin layer of polypyrrole. Results show the hitherto highest reported charge capacities and charging rates for an all polymer paper-based battery. The composite conductive paper material is shown to have a specific surface area of 80 m2 g−1 and batteries based on this material can be charged with currents as high as 600 mA cm−2 with only 6% loss in capacity over 100 subsequent charge and discharge cycles. The aqueous-based batteries, which are entirely based on cellulose and polypyrrole and exhibit charge capacities between 25 and 33 mAh g−1 or 38−50 mAh g−1 per weight of the active material, open up new possibilities for the production of environmentally friendly, cost efficient, up-scalable and lightweight energy storage systems.

Paper-e

Also newly arrived is the Paper-e of the New University of Lisbon, which is an inspired way of printing  transistor circuits by making the gate of the transistor the paper substrate itself. Interestingly, these transistors, made with the superior, new zinc oxide based printed semiconductors ,have much better characteristics than one would expect at first sight and the physics of this is currently being clarified. Needless to say, all the above smart papers for printed electronics can be environmental and biodegradable.

Printed smart shelf

Plastic Electronic GmbH in Austria specializes in capacitive printed electronic structures. For example, its smart shelf consists of polymer film that deforms when things are placed on it and the crossbar conductive patterns on both sides monitor the change in capacitance and thus the position and relative weight of what is on the shelf. Now NTERA, Inc., a leader in all-printed, flexible, color-change display technologies, and plastic electronic GmbH, have entered into a license agreement to develop advanced printed electronics products using NTERA’s flexible printed electrochromic displays.

Piezo flags and eels

Polyvinylidene difluoride PVDF and its derivatives are made into ferroelectric ink used to print non- volatile rewritable random access memory on flexible film. It can also form a film itself that forms a smart substrate for printed electronics, examples being electret-microphones and energy harvesting "flags" and, under the water, "eels".

Smart barriers

Barrier layers to protect delicate printed organic photovoltaic and OLED displays are receiving close attention. Hugely improved barrier layer substrate film is announced by DNP & 3M Display & Graphics Business Lab and companies such as DELO are developing barrier adhesives and inks to go over the patterns printed on these barrier films and to seal encapsulation.

Edible and transparent electronics

Edible printed electronics from Eastman Kodak and Somark Innovations is initially intended to be applied directly to food, pharmaceutical tablets and meat but edible substrates will also be needed, preferably leveraging the electronic functions. Then there is the new discipline of transparent electronics being pursued by Hewlett Packard, Cambridge University in the UK and Fraunhofer ISC in Germany for example.

For full details, visit www.IDTechEx.com/

Developing optimal fuel cells


February 25, 2010

by Takehiko Yaza, Seika Machinery

Executive overview
In developing new fuel cells, there are many obstacles to overcome. For example, gas diffusion must be improved, the volume of catalysts must be reduced and recondensation must be prevented. Another major difficulty is managing water in the fuel cell so that the proton exchange membrane is moisturized and water is quickly discharged from the cathode. Failure to control the water discharge properly will cause flooding at the cathode and a reduction of voltage. There will be a considerable difference depending on the materials selected and the treatment and processing of the materials. Failure to understand the properties of each individual material will make it impossible to develop the optimal fuel cell (Figure 1).

February 25, 2010 – Key factors to consider when developing new fuel cells include: controlling the gas diffusion, permeation, condensation, the reactive area, as well as moisturizing and discharging water. All of these factors depend on the particle size, fiber diameter of the materials and the through-pore structures in them at the electrodes. This article introduces tools that enable better understanding of these properties.

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Figure 1. Current issues for developing fuel cells.

Milling

In North America, ball mills are the most common method for reducing the size of catalyst particles and micro-porous layers of slurry. In a ball mill, the pulverizing energy is generated by steel balls in a gravity-based process. Generally, the milling energy is 1G. By contrast, in a bead mill, the dispersing slurry contains carbon blacks, catalysts and beads, which are mixed together by an agitator inside the milling vessel where particle communion breaks them down into smaller particles. The high-speed of the stirring device generates 100-500G of centrifugal force, providing very high energy. The bead mill makes a large difference in the velocity between the beads and the milled particles. Occasionally, the beads and slurry rotate together and the slurry is not pulverized efficiently. To solve this problem, the AIMEX Alpha Mill (Figure 2) uses an orifice contractile flow vessel. In this configuration, even low-speed rotation generates a very large velocity difference between beads and the slurry. By applying this principle, the milling operation can be carried out very effectively using 30μm beads. Consequently, micrometer-sized carbon black and platinum catalyst particles can be transformed into particles with nm sizes.

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Figure 2. a) Alpha Mill generates high ΔV with small power; b) comparison with the existing model.

When evaluating the efficiency of the slurry pulverization by particle size distribution, we recommend using Horiba Partica LA-950V2. This instrument has the closest correlation to data for NIST traceable to particle size standards and it provides the widest measuring range in the industry.

When the average diameter of the particle to be pulverized is ~0.5μm, even if the materials are crushed, agglomeration is prone to happen. To prevent this phenomenon, a dispersant can be added to the slurry, but this method does have limitations. Therefore, maintaining a high degree of dispersion while coating catalyst and micro-porous layers becomes more important and the Ultrasonic System PRISM series meets this requirement. This coating system uses ultrasonic energy and a nozzleless feed system to eliminate nozzle-blocking problems. The result of these modifications is a 1mm uniform coating thickness. In screen printers and other typical coating systems, it is difficult to provide a thin and uniform thickness without using a pressing machine.

Understanding pore structure

It is necessary to fully understand the pore structure of the coated catalyst layer and the micro porous layer, and the properties relative to water. Although the traditional method of mercury porosimetory generally is used to measure the opened pore structure and volume, the high-pressure measurement method will destroy the pore structure and cannot pick up the functional pores on the application. In contrast, the PMI Capillary Flow Porometer series can measure pore size distribution to determine gas diffusion, water permeability, and the repellent characteristics of the gas diffusion and catalyst layers, without the use of mercury and liquid nitrogen. It realizes automatic and short duration measurements based on the ASTM, bubble point and half-dry methods.

Figure 3 compares measurements made by the Mercury Porosimeter and the Capillary Flow Porometer on a polymer membrane that has only through-pores. The former shows 1-4μm of pore size distribution (peak pore size: 3μm) while the latter shows 1-1.2μm peak pore size:1.1μm difference.

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Figure 3. a) Measurement pore size distribution by Mercury Porosimeter; b) Measurement pore size distribution by Capillary Flow Porometer.

Gas diffusion

Specifically, gas diffusion is the phenomenon in which high-concentration gas flows towards low concentration gas, and eventually the concentration becomes even in the differentiated space with a concentration gradient. Differential pressure results in permeation, but this cannot be called diffusion. There are several measuring instruments for the water vapor transmission rate in the market, however, these instruments can measure only membranes without pores. When fuel cells use high permeability samples, it is difficult to evenly control the pressure at the primary and secondary sides, and the measurement instruments that can measure diffusion at high accuracy are not available. The Seika Moisture Vapor Diffusion Permeameter (MVDP) is integrated using the technologies to maintain high humidity to some degree and prevent condensation by means of temperature control and pressure control. Instead of using batch methods in gas chromatography, MVDP uses real-time technologies to measure concentrations.

As shown in Figure 4, the equipment can measure water vapor diffusion of gas diffusion layers and a proton exchange membrane, as well as oxygen diffusion of moisturized gas. In addition, it can measure gas permeability of generated condensation in the inside of a sample by simulating the flooding phenomenon.

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 Figure 4. a) Measurement in-plane gas permeability test for carbon papers by MVDP; b) oxygen diffusion test for carbon papers by MVDP.

Many fuel cell materials are treated with a waterproofing chemical on the surface to prevent condensation, or are hydrophilically processed to retain moisture. The characteristics of Teflon-coated samples change with immersion time and temperature. The Seika Liquid Intrusion Meter measures the changes in properties and helps optimize fuel cell performance (Figure 5). A liquid permeability test using ultra-low differential pressure can monitor permeated water from large through pores in order of pore size.

The Mesys USM-200 thickness gauge is effective for the management of thickness for the proton exchange membrane manufacturing process. This method emits no radiation, and does not come in contact with, or destroy the samples during measurement.

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 Figure 5. a) Hydrophobic sample measurement; b) Hydrophilic sample measurement.

Conclusion

Because it is difficult to visualize the inner operation of a fuel cell — it is covered by separators made of metal or carbon — it is necessary to use measurements (to get structural information) and simulations (to get process information). Using these direct approaches brings in new ideas and compensates simulation results on super computers. Furthermore, using the aforementioned instruments, we developed simulators for monitoring gas permeability in chronological order on blocking pores by condensation (flooding) at GDL, while also creating a gas visualization system for gas diffusion and the concentration at GDL. However, these are only one set of requirements that need to be addressed before high-volume manufacturing of high-efficiency, cost-effective fuel cells can be realized. Going forward, we would like to discuss additional research proposals with interested parties and propose new equipment necessary to develop optimal fuel cells.

Acknowledgment

Teflon is a registered trademark of DuPont.

Biography

Takehiko Yaza has a bachelor of arts in economics from Takasaki City U. of Economics. He is a senior sales manager at Seika Machinery Inc., 3528 Torrance Blvd., Suite 100, Torrance, CA 90503 USA; ph.: (+1) 310.540.7310; e-mail [email protected]; www.seikausa.com.

December 14, 2009 – At this year’s International Electron Devices Meeting (IEDM), IMEC and partners TNO (a Netherlands-based research group) and the Holst Center (IMEC–TNO joint center set up in 2005), disclosed their latest work in creating a MEMS-based piezoelectric energy harvesting device with record power generation, and a "world-first" organic transponder circuit with bit rate of 50kbits/s, nearing requirements for Electronic Product Coding (EPC) standards.

New mark in MEMS piezoelectric energy harvesting

Micromachined devices to harvest energy from vibrations typically operate in a range of 150-1000Hz, ideally used to convert energy from vibrations in machines, engines, and other industrial appliances. Their tiny size also makes them useful for powering miniaturized autonomous sensor nodes.

In work within the Holst Center’s program on micropower generation and storage, IMEC researchers created a temperature sensor that can wirelessly and autonomously transmit data — a wafer-level-packaged MEMS-based harvester, generating a record 85µW electrical power from vibrations. The harvester is a Si mass suspended on a beam, built used CMOS-compatible MEMS processes on 6" silicon wafers. Changing the dimensions of the beam and mass can modify the harvester’s resonance frequency for any value in the 150-1200Hz range.

Among the achievements IMEC noted in its work:

– Aluminum nitride is used instead of lead zirconate titanate as the piezoelectric material; AlN enables more favorable materials parameters and ease of processing, e.g. up to 3× faster deposition and better composition control due to AlN’s stoichiometric nature.
– A wafer-scale process was developed to protect the piezoelectric devices in a package: glass covers coated with an adhesive, vacuum-bonded on top and bottom of the process wafer, and diced. Power output was shown to increase significantly using a vacuum package vs. packaging in atmospheric pressure.

The harvester was connected to a wireless temperature sensor built from off-the-shelf components. After power optimization, the sensor’s energy consumption was reduced from 1.5mW to ~10µW, a three-orders-of-magnitude improvement. Subjected to vibrations at 353Hz at 0.64g (a realistic amplitude) the system generated sufficient power to measure and transmit environmental temperature to a base station with 15sec interval.


Fully autonomous wireless temperature sensor powered by a vibrational energy harvester. (Source: IMEC)

The achievement proves the feasibility of building fully autonomous energy harvesters for industrial applications, IMEC says. Once it is developed to maturity (by industry, not IMEC or Holst), the technology could power sensors for applications such as tire-pressure monitoring systems (TPMS) and predictive maintenance of moving or rotating machine parts.

 

"World’s first" 50kbit/s organic transponder

Another declaration at IEDM was the debut from IMEC, TNO, and Holst of the world’s first organic transponder circuit with 50kbits/sec bit rate, which approaches requirements for Electronic Product Coding (EPC) standards, which support the use of radio-frequency identification (RFID).

Flexible circuits are attractive for both manufacturing as well as final products in applications such as plastic RFID tags, but would need to adhere to EPC specs for item-level tagging, which requires 50kb/s bit rate. The Holst Center, wtih IMEC and TNO, have developed an 8-bit flexible transponder circuit on foil using pentacene as the semiconductor material and a high-k gate dielectric. The device’s current drive extends well beyond previous efforts with 1-2kbits/s bitrates, pushing all the way to >50kbits/s data rate, "which compares favorably" with such EPC specs.

RFID is already being used in high-volume logistics applications, e.g. pallet-level logistics; the next step is to use EPC tags at the package level, and eventually on individual items (item-level tagging). Organic electronic technology offers the promise of, and is being explored to be used for, high-volume and low-cost manufacturing of simple electronic circuits. "The new results demonstrate that the technology is now on the way to reach EPC compatibility," IMEC said in a statement.

December 8, 2009 – Researchers from Stanford U. have devised a way to turn ordinary paper into a battery: slather it with an inky concoction of carbon nanotubes and silver nanowires, and then cook it.

Coating a sheet of paper with ink containing carbon nanotubes and silver nanowires turns the paper into a "supercapacitor," which holds an electric charge like a battery but for a shorter period of time, and stores/discharges it much more rapidly. The particular version they came up with can last through 40,000 charge-discharge cycles, "at least an order of magnitude" better than conventional lithium-ion batteries, they claim. The thicker the coating, the greater the electrical storage/conductivity.

Yi Cui, assistant professor of materials science and engineering at Stanford, had previously done work on making such capacitive creations using plastics, but found the nanoink adheres better to the paper-based versions and makes them more durable; it can be folded and even soaked in acids or bases and performance does not degrade ("We haven’t tested what happens when you burn it," Cui quipped in a statement), and the CNTs resist peeling. No added adhesives also eliminates a factor that would otherwise decrease performance and increase production costs, the researchers note.

From their research, published this week by the Proceedings of the National Academy of Sciences:

Here, we show that commercially available paper can be made highly conductive with a sheet resistance as low as 1 ohm per square (Ω/sq) by using simple solution processes to achieve conformal coating of single-walled carbon nanotube (CNT) and silver nanowire films. […] When only CNT mass is considered, a specific capacitance of 200 F/g, a specific energy of 30-47 Watt-hour/kilogram (Wh/kg), a specific power of 200,000 W/kg, and a stable cycling life over 40,000 cycles are achieved. These values are much better than those of devices on other flat substrates, such as plastics. Even in a case in which the weight of all of the dead components is considered, a specific energy of 7.5 Wh/kg is achieved.

The main application for this work would be large-scale storage of electricity on the grid, in wind farms and solar energy systems. Other potential applications range from serving as the nonmetallic current collector in Li-ion batteries, to brushing onto a wall to create a conductive energy storage device to which LEDs could be connected, to use in electric or hybrid cars. "Society really needs a low-cost, high-performance energy storage device, such as batteries and simple supercapacitors," Cui said. "I don’t think it will be limited to just energy storage devices," noted Peidong Yang, professor of chemistry at the U. of California-Berkeley, quoted by Stanford. "This is potentially a very nice, low-cost, flexible electrode for any electrical device."

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SEM images of: (A) interface between carbon nanotubes and silver nanowires on Xerox paper, (B) Ag NW film, and (C) CNT film. (D) The resistance scaling with the Ag NW electrode distance. (Inset) Contact resistance measurement scheme. (Source: PNAS)

 

September 15, 2009:  Energy harvesting is popularly defined as converting ambient power to electricity to make small devices self-sufficient, often for decades, possibly even hundreds of years. It is certainly not renewable energy on the heroic scale of replacing power stations with grid electricity from the power of the wind, waves, etc. However, there is a middle ground of making things such as trucks and railway stations more energy efficient. For example, regenerative braking and harvesting electricity from shock absorbers and exhaust heat in vehicles makes them more energy efficient. The trans-Australia race involves cars that receive all their motive power from photovoltaics. Japan is already harvesting energy from travellers walking over flexing paving at ticket barriers; this electricity being used to power displays.

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Energy harvesting for small devices, renewable energy replacing power stations, and what comes between. (Source: IDTechEx report, "Energy harvesting and storage 2009-2019")

For both the core energy harvesting business and the harvesting within bigger things, the question arises as to what types of energy harvester will attract the big money, creating billion-dollar businesses. Academia is not necessarily driven by commercial potential, so the huge leap in work on piezoelectrics and photovoltaics may or may not be an indication that these types of energy harvesting will come out on top. Other candidates include thermovoltaics (exploiting heat differences) and electrodynamics. There are also dozens of other curiosities such as use of magnetostriction, electrostatic capacitive devices including electroactive polymers, electrets, and so on — doing it all with microelectromechanical systems (MEMS).

Wide variety of applications

All these energy-harvesting efforts are being applied to an impressive variety of applications. Piezoelectrics serve in the gas lighter and the light switch that have no wiring or battery. Photovoltaics appears in calculators, street furniture, satellites, and much more — and now we have transparent photovoltaics in the form of flexible films, converting ultraviolet, infrared, and visible light and other versions tolerant of narrow angles of incidence and low levels of light. All this will hugely widen the number of possible applications.

Electrodynamics has moved from the bicycle dynamo to vibration harvesting, electricity from flexing floors and pavements, micro wind turbines and even powering the implanted heart defibrillator or pacemaker from the heart itself — no need to cut you open to change your battery anymore. Universities should do much more to support this work.

Thermovoltaics is being tested in implants and on car exhaust pipes, not just in engines. Ultralow-cost laptops for the third world employ both photovoltaics and electrodynamics where one project finds that a ripcord is preferred to a crank.

Some energy-harvesting options lean toward the strange. The US military is testing it for robot jellyfish and robot bats for surveillance. So-called wireless sensor nodes are being developed, dropped from helicopters and self-organizing in a self-healing wireless mesh network; applications include monitoring forest fires and other natural disasters as well as pollution outages over vast, inaccessible terrain. Energy harvesting will do away with the need for batteries here.

Counting the dollars

IDTechEx has analyzed a large number of energy-harvesting activities, producing 10-year forecasts for everything from self-sufficient wristwatches to mobile phones that will never need a charger to light switches and controls that have no wiring and no batteries when fitted in buildings. We find that the total market in 2019 will exceed $4 billion (segmented roughly below) — even the niche opportunities are significant.

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Estimated value share of technologies in the global energy harvesting market in 2019. (Source: IDTechEx report, "Energy harvesting and storage 2009-2019")

We see a clear route to billion-dollar businesses in photovoltaic and electrodynamic energy harvesting — even ignoring energy storage and associated electronics. The impressive effort on piezoelectric energy harvesting in universities and research centers (such as Germany’s Fraunhofer Institutes) may yet come up with something bigger than that portrayed above. However, as yet, we find it difficult to envisage piezoelectrics powering many consumer items such as wristwatches, mobile phones, laptops, e-books, and others.

The key to wireless sensor networks

While it is generally accepted that 70%-90% of envisaged uses of wireless sensor networks cannot succeed without some form of energy harvesting, replacing short-lived primary batteries in the nodes, it is far from clear that piezoelectrics will be the favored solution here. In military, aerospace, and other industrial and healthcare applications, piezoelectrics has a place, such as harvesting vibration; the piezoelectric light switch and piezo actuators in general have a great future. However, we have difficulty in seeing a large income arising from the harvesting module itself, as is clear with the photovoltaic and electrodynamic applications. Indeed, with these two technologies there are already large commercial successes in 2009.

The greater market

Within the term "energy harvesting" some include extra markets such as ambient power conversion in vehicles and railway stations. In vehicles, it will be thermovoltaics that harnesses exhaust heat. Electrodynamics will harness power from shock absorbers (recently announced by the Massachusetts Institute of Technology) and regenerative braking is already a reality. Moving flooring and pavements generate power from people walking over them, achieved electrodynamically or by piezo power — and the same is true of vibration harvesting in bridges, roads, and aircraft.

Raghu Das is CEO of IDTechEx in Cambridge, UK, and event director of the IDTechEx conference Energy Harvesting and Storage USA, Nov. 3-4 in Denver, CO.

NanoDynamics goes under


July 31, 2009

July 30, 2009: NanoDynamics has ceased operations and filed Chapter 7 bankruptcy, unable to find financing after a pair of abandoned IPOs and the current stagnant funding environment. This particular filing is a liquidation move, not a restructuring as would be in a Chapter 11 filing.

The company, which spanned three sites in NY, PA, and OH and nearly 100 employees working on nanoparticles used in fuel cells, water filtration, and construction materials, had announced nearly $2.5M in federal funding for two projects in January, but apparently that wasn’t enough. “While NanoDynamics has technology and products that the world needs as well as an intelligent and dedicated team of employees, the funding to continue simply does not exist,” CEO William Cann reportedly told employees in an email, according to the Buffalo News.

The Business First of Buffalo noted 2008 regulatory filings indicating NanoDynamics had about $8.8M in sales but $34M in losses. “Given the current financial market conditions the ability to raise capital is very, very difficult,” said Raymond Fink from Harter Seacrest & Emery LLP who is representing the company in bankruptcy proceedings, told the paper, “particularly for a company that is primarily research and development and hasn’t quite yet gotten most of its products to the market.”

(July 10, 2009) DURHAM, N.C. &#151 Nextreme Thermal Solutions raised $8 million in additional Series B financing from undisclosed corporate investors. Nextreme has now raised more than $21 million in Series B financing and $35 million since its inception in 2004. The additional funding will be used to expand Nextreme’s presence and products for energy harvesting for micro and portable power along with solidifying its position for thermal management products in computing, consumer, and mobile markets.

Nextreme offers microscale cooling and thermal energy harvesting solutions that integrate directly into electronic and consumer product packaging. Nextreme’s scalable cooling and power generation solutions have the potential to have a major impact on mainstream industries such as automotive, computing, consumer, mobile, and telecommunications. Applications for the technology include: CPU/GPU hot spot cooling, power MOSFET cooling, LED cooling, laser diode cooling, thermal energy scavenging, thermal control in consumer products, power harvesting for sensors, and process control.

Increased functionality in a smaller footprint has been a constant driver in electronics and consumer products throughout the past 30 years. Additionally, the need for improved energy efficiency and micro-scale, distributed power generation capability has emerged as a driver in many applications. These trends have translated into significant thermal and power problems in a host of industries. Nextreme offers one of the few, fundamentally new innovations that addresses both thermal management and power generation in a fully scalable approach. Nextreme’s technology is driven by form factor, device performance and cost &#151 all of which are expected to drive adoption of this technology and fuel the company’s growth.

“This funding from corporate investors represents a very significant validation of our company and technology, especially during these challenging times,” said Jesko von Windheim, CEO of Nextreme. “With our Series B financing now fully in place, the company is well positioned to execute its product development and sales plan over the next two years.”

Contact Nextreme at www.nextreme.com.

July 8, 2009 – Magma Design Automation is making its splash into the world of solar photovoltaics with a new software package to help solar cell manufacturers identify and correct causes of yield loss and thus improve energy conversion.

The Yield Manager Solar software provides a more “holistic” approach to gathering, analyzing, and correlating all of the metrology, inspection and performance data used in solar cell manufacturing that comes from a variety of manufacturing equipment and in a variety of unique formats. Data can be filtered by lot, ingot, substrate, wafer, and other parameters, and the software can generate customized reports and dashboards. Armed with this information, engineers can quickly identify and correct root causes of solar energy conversion efficiency and yield degradation caused by subtle fab processing fluctuations or instability — e.g., monitoring, reporting, and alerting about a non-uniform doping level on a process step, which could cause a drop in sheet resistance and reduce a solar cell’s energy conversion efficiency.


(Source: Magma Design Automation)
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“With YieldManager Solar, fabs can carefully monitor the entire solar cell manufacturing process over time and create highly customized reports that enable them to improve the energy conversion efficiency, reduce the manufacturing costs and increase the yield of silicon wafer-based solar cells,” said Ankush Oberai, VP of Magma’s fab analysis business unit, in a statement.


YieldManager Solar exports raw data and generates customized drill-down charts for accurate analysis. (Source: Magma Design Automation)
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Simultaneous with the Yield Manager Solar launch, Magma has signed a deal with Orion Metrology to integrate it with Orion’s inline inspection tools for PV solar cell manufacturers, allowing them to monitor random and parametric inline defects and instantaneously feed this information back to manufacturing to minimize the impact and severity of defects, improving yield and product efficiencies. YieldManager also will become the central data analysis component for Orion’s inline process and parametric measurement applications.

“The key to improving product efficiencies and manufacturing productivity is to identify how carrier lifetimes are being affected by process layer over a large area — from the surface to the bulk of the material — on 100% of the production throughput,” stated Orion Metrology CEO Joe Foster. “Our inline approach ensures a more accurate characterization of process variation. If monitored and corrected quickly, even small changes can yield dramatic improvements in product yield and efficiency, significantly increasing the value of the solar panels. Magma’s YieldManager Solar enables the inline and metrology data to be reported, managed, and understood in real time.”