Brown liquor and solar cells to provide sustainable electricity

 A breakthrough for inexpensive electricity from solar cells, and a massive investment in wind power, will mean a need to store energy in an intelligent way. According to research at Linköping University, published in Science, batteries of biological waste products from pulp mills could provide the solution.

Organic solar cells based on conductive plastic is a low cost alternative that has achieved high enough performance to be upscaled and, in turn, become competitive. However, solar electricity must be able to be stored from day to night, as well as electricity from wind turbines from windy to calm days.

In conventional batteries metal oxides conduct the charge. Materials, such as cobalt, are expensive and a limited resource, therefore, low cost solutions are sought preferably with renewable materials.

"Nature solved the problem long ago," says Olle Inganäs, professor of biomolecular and organic electronics at Linköping University (LiU) and lead author of the article in a recent edition of Science.

He drew inspiration from the process of photosynthesis, where electrons charged by solar energy are transported by quinones; electrochemically active molecules based on benzene rings composed of six carbon atoms. Inganäs chose the raw material brown liquor that is a by-product from the manufacture of paper pulp. The brown liquor is largely composed of lignin, a biological polymer in the plant cell walls.

To utilise the quinones as charge carriers in batteries, Inganäs and his Polish colleague Grzegorz Milczarek devised a thin film from a mixture of pyrrole and lignin derivatives from the brown liquor. The film, 0.5 microns in thickness, is used as a cathode in the battery.

The goal is to offer ways to store renewable electricity where it is produced, without constructing up large grids. In several countries, major wind power investments are planned. Meanwhile, the performance of cheap organic solar cells has now reached a critical level. A research team at the University of California, Los Angeles, has recently reported efficiency of more than 10 percent of the energy of the captured sunlight.

According to Inganäs who for many years conducted research on organic solar cells, the efficiency is sufficient to initiate an industrial scale up of the technology.

"Now we need more research into new energy storage based on cheap and renewable raw materials. Lignin constitutes 20-30 percent of the biomass of a tree, so it's a source that never ends."

Story Source:

The above story is reprinted from materials provided by Linköping University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Grzegorz Milczarek and Olle Inganäs. Renewable Cathode Materials from Biopolymer/Conjugated Polymer Interpenetrating Networks. Science, 2012 DOI: 10.1126/science.1215159]

Electricity and carbon dioxide used to generate alternative fuel

 Imagine being able to use electricity to power your car -- even if it's not an electric vehicle. Researchers at the UCLA Henry Samueli School of Engineering and Applied Science have for the first time demonstrated a method for converting carbon dioxide into liquid fuel isobutanol using electricity.

Today, electrical energy generated by various methods is still difficult to store efficiently. Chemical batteries, hydraulic pumping and water splitting suffer from low energy-density storage or incompatibility with current transportation infrastructure.

In a study published March 30 in the journal Science, James Liao, UCLA's Ralph M. Parsons Foundation Chair in Chemical Engineering, and his team report a method for storing electrical energy as chemical energy in higher alcohols, which can be used as liquid transportation fuels.

"The current way to store electricity is with lithium ion batteries, in which the density is low, but when you store it in liquid fuel, the density could actually be very high," Liao said. "In addition, we have the potential to use electricity as transportation fuel without needing to change current infrastructure."

Liao and his team genetically engineered a lithoautotrophic microorganism known as Ralstonia eutropha H16 to produce isobutanol and 3-methyl-1-butanol in an electro-bioreactor using carbon dioxide as the sole carbon source and electricity as the sole energy input.

Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. There are two parts to photosynthesis -- a light reaction and a dark reaction. The light reaction converts light energy to chemical energy and must take place in the light. The dark reaction, which converts CO2 to sugar, doesn't directly need light to occur.

"We've been able to separate the light reaction from the dark reaction and instead of using biological photosynthesis, we are using solar panels to convert the sunlight to electrical energy, then to a chemical intermediate, and using that to power carbon dioxide fixation to produce the fuel," Liao said. "This method could be more efficient than the biological system."

Liao explained that with biological systems, the plants used require large areas of agricultural land. However, because Liao's method does not require the light and dark reactions to take place together, solar panels, for example, can be built in the desert or on rooftops.

Theoretically, the hydrogen generated by solar electricity can drive CO2 conversion in lithoautotrophic microorganisms engineered to synthesize high-energy density liquid fuels. But the low solubility, low mass-transfer rate and the safety issues surrounding hydrogen limit the efficiency and scalability of such processes. Instead Liao's team found formic acid to be a favorable substitute and efficient energy carrier.

"Instead of using hydrogen, we use formic acid as the intermediary," Liao said. "We use electricity to generate formic acid and then use the formic acid to power the CO2 fixation in bacteria in the dark to produce isobutanol and higher alcohols."

The electrochemical formate production and the biological CO2 fixation and higher alcohol synthesis now open up the possibility of electricity-driven bioconversion of CO2 to a variety of chemicals. In addition, the transformation of formate into liquid fuel will also play an important role in the biomass refinery process, according to Liao.

"We've demonstrated the principle, and now we think we can scale up," he said. "That's our next step."

The study was funded by a grant from the U.S. Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E).

Story Source:

The above story is reprinted from materials provided by University of California - Los Angeles. The original article was written by Wileen Wong Kromhout.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

H. Li, P. H. Opgenorth, D. G. Wernick, S. Rogers, T.-Y. Wu, W. Higashide, P. Malati, Y.-X. Huo, K. M. Cho, J. C. Liao. Integrated Electromicrobial Conversion of CO2 to Higher Alcohols. Science, 2012; 335 (6076): 1596 DOI: 10.1126/science.1217643

Cyborg snail produces electricity

But whereas the grapes and cockroaches could generate electricity for just days or weeks, Evgeny Katz, a professor of chemistry at Clarkson University in Potsdam, New York, and colleagues have shown that the snail can generate electricity for many months at a time. And in spite of the electrodes in their shells, the snails live long, healthy lives.

“The animals are quite fit - they eat, drink and crawl,” Katz told Nature News. "We take care to keep them alive and happy.”

Although a snail's tissues and organs are bathed in blood, or haemolymph, it takes time to regenerate its glucose levels, which means snails don't generate very large amounts of power. For the first few minutes, the researchers could extract 7.45 microwatts, but this power decreased to just 0.16 microwatts during long-term, continuous extraction. The main cause of this decay comes from the local depletion of glucose at the electrode surface. Still, the snail's eating and resting could sufficiently regenerate its overall glucose levels, allowing it to “recharge” and produce sustainable electrical power.

These snails - as well as other potential electrified creatures such as worms and insects - could be useful for powering low-power devices, such as sensors and wireless transmitters. The US Department of Defense is funding cyborg research in the hopes of creating bugs that can gather information about their environment while crawling around. Researchers are also investigating medical applications, in which a patient's implantable biofuel cell could use his or her own blood glucose to power medical devices such as pacemakers.

In the future, the researchers at Clarkson University plan to electrify lobsters in the same way as the snails, with the hopes that the larger animals' metabolism could provide more power.

More information: Lenka Halámková, et al. "Implanted Biofuel Cell Operating in a Living Snail." Journal of the American Chemical Society. DOI: 10.1021/ja211714w

Abstract
Implantable biofuel cells have been suggested as sustainable micropower sources operating in living organisms, but such bioelectronic systems are still exotic and very challenging to design. Very few examples of abiotic and enzyme-based biofuel cells operating in animals in vivo have been reported. Implantation of biocatalytic electrodes and extraction of electrical power from small living creatures is even more difficult and has not been achieved to date. Here we report on the first implanted biofuel cell continuously operating in a snail and producing electrical power over a long period of time using physiologically produced glucose as a fuel. The “electrified” snail, being a biotechnological living “device”, was able to regenerate glucose consumed by biocatalytic electrodes, upon appropriate feeding and relaxing, and then produce a new “portion” of electrical energy. The snail with the implanted biofuel cell will be able to operate in a natural environment, producing sustainable electrical micropower for activating various bioelectronic devices.

 

Implanted biofuel cell converts bug's chemistry into electricity: Scientists take step toward cyborgs

The finding is yet another in a growing list from universities across the country that could bring the creation of insect cyborgs – touted as possible first responders to super spies – out of science fiction and into reality. In this case, the power supply, while small, doesn't rely on movement, light or batteries, just normal feeding.

The work is published in the online Journal of the American Chemical Society.

"It is virtually impossible to start from scratch and make something that works like an insect," said Daniel Scherson, chemistry professor at Case Western Reserve and senior author of the paper.

"Using an insect is likely to prove far easier," Scherson said. "For that, you need electrical energy to power sensors or to excite the neurons to make the insect do as you want, by generating enough power out of the insect itself."

Scherson teamed with graduate student Michelle Rasmussen, Biology Professor Roy E. Ritzmann, Chemistry Professor Irene Lee and Biology Research Assistant Alan J. Pollack to develop an implantable biofuel cell to provide usable power.

The key to converting the chemical energy is using enzymes in series at the anode.

The first enzyme breaks the sugar, trehalose, which a cockroach constantly produces from its food, into two simpler sugars, called monosaccharides. The second enzyme oxidizes the monosaccharides, releasing electrons.

The current flows as electrons are drawn to the cathode, where oxygen from air takes up the electrons and is reduced to water.

After testing the system using trehalose solutions, prototype electrodes were inserted in a blood sinus in the abdomen of a female cockroach, away from critical internal organs.

"Insects have an open circulatory system so the blood is not under much pressure," Ritzmann explained. "So, unlike say a vertebrate, where if you pushed a probe into a vein or worse an artery (which is very high pressure) blood does not come out at any pressure. So, basically, this is really pretty benign. In fact, it is not unusual for the insect to right itself and walk or run away afterward."

The researchers found the cockroaches suffered no long-term damage, which bodes well for long-term use.

To determine the output of the fuel cell, the group used an instrument called a potentiostat. Maximum power density reached nearly 100 microwatts per square centimeter at 0.2 volts. Maximum current density was about 450 microamps per square centimeter.

The study was five years in the making. Progress stalled for nearly a year due to difficulties with trehalase – the first enzyme used in the series.

Lee suggested they have the trehalase gene chemically synthesized to generate an expression plasmid, which is a DNA molecule separate from chromosomal DNA, to allow the production of large quantities of purified enzyme from Escherichia coli. "Michelle then began collecting enzyme that proved to have much higher specific activities than those obtained from commercial sources," Lee said. "The new enzyme led to success."

The researchers are now taking several steps to move the technology forward: miniaturizing the fuel cell so that it can be fully implanted and allow an insect to run or fly normally; investigating materials that may last long inside of an insect, working with other researchers to build a signal transmitter that can run on little energy; adding a lightweight rechargeable battery.

"It's possible the system could be used intermittently," Scherson said. "An insect equipped with a sensor could measure the amount of noxious gas in a room, broadcast the finding, shut down and recharge for an hour, then take a new measurement and broadcast again."

Provided by Case Western Reserve University (news : web)

Converting waste heat into electricity

More than half of today's energy consumption is squandered in useless waste heat, such as the heat from refrigerators and all sorts of gadgets and the heat from factories and power plants. The energy losses are even greater in cars. Automobile motors only manage to utilise 30 per cent of the energy they generate. The rest of it is lost. Part of the heat loss ends up as warm brakes and a hot exhaust pipe.

Scientists at the Centre for Materials Science and Nanotechnology at the University of Oslo in Norway (UiO) are now collaborating with SINTEF (the Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology) to develop a new environmentally friendly technology called thermoelectricity, which can convert waste heat into electricity. To put it briefly, the technology involves making use of temperature differences.

Today: Toxic and expensive

Thermoelectric materials are put to many uses in space flight. When a space probe travels far enough away from the sun, its solar cells cease to work. Batteries have much too short a lifetime. Nuclear power cannot be used. However, a lump of Plutonium will do the trick.

With a temperature of a thousand degrees, it is hot. Outer space is cold. Thanks to the temperature difference, the space probe gets enough electricity.

Plutonium is a good solution for space probes that will not return to earth, but it is not a practical solution for cars and other earthly objects.

Thermoelectric materials are also currently used in the type of cooler bags that keep things cold without making use of their own cooling elements. These cooler bags are full of the elements Lead and Tellurium. Both of these substances are also toxic.

"We want to replace them with inexpensive and readily available substances. Moreover, there is not enough Tellurium to equip all of the cars in the world," says Ole Martin Lovvik, who is both an associate professor in the Department of Physics at the University of Oslo and a senior scientist at SINTEF.

Tomorrow: Environmentally friendly and inexpensive

With the current technology, it is possible to recover scarcely ten per cent of the lost energy. Together with the team of scientists led by Professor Johan Tafto, Lovvik is now searching for pollution-free, inexpensive materials that can recover fifteen per cent of all energy losses. That is an improvement of fully fifty per cent.

"I think we will manage to solve this problem with nanotechnology. The technology is simple and flexible and is almost too good to be true. In the long run, the technology can utilise all heat sources, such as solar energy and geothermal energy. The only limits are in our imagination," states Lovvik to the research magazine Apollon at University of Oslo

The new technology will initially be put to use in thermoelectric generators in cars. Several major automobile manufacturers are already interested. Lovvik and his colleagues are currently discussing the situation with General Motors.

"Modern cars need a lot of electricity. By covering the exhaust system with thermoelectric plates, the heat from the exhaust system can increase the car's efficiency by almost ten per cent at a single stroke. If we succeed, this will be a revolution in the modern automotive industry."

The new technology can also replace the hum of today's refrigerator.

"In the future, refrigerators can be soundless and built into cabinets without any movable parts and with the possibility of maintaining different temperatures in each compartment.

In order to extract as much energy as possible, the temperature difference should be as large as possible.

"Initially then, we want to utilise high-temperature waste heat, but there is also an upper limit."

If it becomes too hot, some materials will break down either by melting or by being transformed into other materials. That would mean that they wouldn't work any more.

Apparently self-contradictory.

In order to create thermoelectric materials, physicists have to resolve an apparent paradox. A metal conducts both electricity and heat. An insulator conducts neither electricity nor heat.

A good thermoelectric material ought to be a semi-conductor with very special properties: Its thermal resistance must be as high as possible at the same time as current must flow through it easily.

"This is not a simple combination, and it may even sound like a self-contradiction. The best solution is to create small structures that reflect the heat waves at the same time as the current is not reflected."

In order to understand why this is so, you must first understand how heat is dissipated. When a material becomes hot, the atoms vibrate. The hotter it becomes, the greater the vibrations, and when an atom vibrates, it will also affect the vibration of the adjacent atom.

When these vibrations spread through the material, they can be called heat waves. If we create barriers in the material so that some atoms vibrate at different frequencies from their adjacent atoms, the heat will not be so easily dissipated.

"Moreover, the atomic barrier must be created in such a way that it does not prevent the electric current from flowing through it."

Grinding nano-cavities at minus 196 degrees.

The scientists have found a method of creating these atomic barriers. The barriers are introduced densely in the special semi-conductors.

"We have achieved this by using a completely new "mill." Just as the miller grinds grain, the scientists will grind down semi-conductors to nano-sized grains. They will do that by cooling them down with liquid Nitrogen to minus 196 degrees. That makes the material more brittle, less sticky and easier to crush. It is important to grind down the grains as small as possible. Afterwards the grains are glued back together again, and in this way the barriers are created."

"The small irregularities in the barriers reflect the heat waves," says Lovvik.

The team of scientists uses an electron microscope to examine the micro-structures in the material.

"We have now discovered new nano-cavities in the materials and learned more about how they reflect heat waves."

The thermal resistance is measured in the Norwegian Micro and Nano Laboratories that are jointly operated by UiO and SINTEF. Lovvik's specialised field is mathematical models. With these models, he can predict how the atoms should be arranged in the materials.

Renaissance for cobalt

The scientists are now searching for the next generation of thermoelectric materials. They have just tested the cobalt arsenide mineral, skutterudite, which may be found at Skutterud at Blafarvevarket in Modum, Norway.

"It was just recently discovered that skutterudite may have atoms located in small nano-cavities. These cavities act as barriers to heat dissipation," concludes Lovvik.

Story Source:

The above story is reprinted from materials provided by University of Oslo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Chinese team develop fuel cell that can clean water as it generates electricity

Yanbiao Liu and his colleagues from Shanghai Jiao Tong University, have succeeded in building a device capable of both cleaning wastewater and producing electricity from it. Using light as an energy source the team created a photo-catalytic fuel cell that used a titanium dioxide nanotube-array anode and a cathode based on platinum. The light energy degrades the organic material found in the wastewater and in the process generates electrons which pass through the cathode converting it into electricity. The team has published its results on Water Science & Technology.

Liu notes in the paper, that wastewater (the stuff that goes down the toilet when flushed) or sewage, as it’s more commonly known in other countries, is a great source of environmental pollution and at the same time, is a truly important and often overlooked source of energy, which, unfortunately generally is not collected and used. It’s also an expensive by-product of human existence. Every day billions of people contribute to the ever growing problem of what to do with all the human waste that is created.

In addition to organic material, wastewater often contains other materials that need to be removed in order to reuse the water for other purposes. In their lab the team tested their fuel cell’s ability to separate clear aromatics (perfumes), azo dyes, pharmaceuticals, personal care products and endocrine-disrupting compounds (birth control pill chemicals that wind up in urine) from wastewater samples and found they were able to separate them completely from the organic material thus producing clean water.

To allow the system to use visible and regular sunlight rather than UV, the team modified the electrodes with semiconductors (such as CdS) which means of course the system, if industrialized, could be used outside as an add-on perhaps to existing wastewater treatment plants.
So far the team hasn’t listed cost estimates for building an electrical/wastewater treatment facility with their new technology, but it’s not hard to see how useful such a plant would be in areas where sewage is sometimes not treated at all, but simply dumped into rivers or streams, or worse, in the streets. In addition to helping clean up such places, the people in those areas would benefit from the electricity that would be produced in the process.

More information: A TiO2-nanotube-array-based photocatalytic fuel cell using refractory organic compounds as substrates for electricity generation, Chem. Commun., 2011, Advance Article, DOI: 10.1039/C1CC13388H

Abstract
A TiO2-nanotube-array-based photocatalytic fuel cell system was established for generation of electricity from various refractory organic compounds and simultaneous wastewater treatment. The present system can respond to visible light and produce obviously enhanced cell performance when a narrow band-gap semiconductor (i.e. Cu2O and CdS) was combined with TiO2 nanotubes.

 

Generating 'green' electricity: Waste heat converted to electricity using new alloy

University of Minnesota engineering researchers in the College of Science and Engineering have recently discovered a new alloy material that converts heat directly into electricity. This revolutionary energy conversion method is in the early stages of development, but it could have wide-sweeping impact on creating environmentally friendly electricity from waste heat sources.

Researchers say the material could potentially be used to capture waste heat from a car's exhaust that would heat the material and produce electricity for charging the battery in a hybrid car. Other possible future uses include capturing rejected heat from industrial and power plants or temperature differences in the ocean to create electricity. The research team is looking into possible commercialization of the technology.

"This research is very promising because it presents an entirely new method for energy conversion that's never been done before," said University of Minnesota aerospace engineering and mechanics professor Richard James, who led the research team."It's also the ultimate 'green' way to create electricity because it uses waste heat to create electricity with no carbon dioxide."

To create the material, the research team combined elements at the atomic level to create a new multiferroic alloy, Ni45Co5Mn40Sn10. Multiferroic materials combine unusual elastic, magnetic and electric properties. The alloy Ni45Co5Mn40Sn10 achieves multiferroism by undergoing a highly reversible phase transformation where one solid turns into another solid. During this phase transformation the alloy undergoes changes in its magnetic properties that are exploited in the energy conversion device.

During a small-scale demonstration in a University of Minnesota lab, the new material created by the researchers begins as a non-magnetic material, then suddenly becomes strongly magnetic when the temperature is raised a small amount. When this happens, the material absorbs heat and spontaneously produces electricity in a surrounding coil. Some of this heat energy is lost in a process called hysteresis. A critical discovery of the team is a systematic way to minimize hysteresis in phase transformations. The team's research was recently published in the first issue of the new scientific journal Advanced Energy Materials.

Watch a short research video of the new material suddenly become magnetic when heated: http://z.umn.edu/conversionvideo.

In addition to Professor James, other members of the research team include University of Minnesota aerospace engineering and mechanics post-doctoral researchers Vijay Srivastava and Kanwal Bhatti, and Ph.D. student Yintao Song. The team is also working with University of Minnesota chemical engineering and materials science professor Christopher Leighton to create a thin film of the material that could be used, for example, to convert some of the waste heat from computers into electricity.

"This research crosses all boundaries of science and engineering," James said. "It includes engineering, physics, materials, chemistry, mathematics and more. It has required all of us within the university's College of Science and Engineering to work together to think in new ways."

Funding for early research on the alloy came from a Multidisciplinary University Research Initiative (MURI) grant from the U.S. Office of Naval Research (involving other universities including the California Institute of Technology, Rutgers University, University of Washington and University of Maryland), and research grants from the U.S. Air Force and the National Science Foundation. The research is also tentatively funded by a small seed grant from the University of Minnesota's Initiative for Renewable Energy and the Environment.

Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by University of Minnesota.

Journal Reference:

Vijay Srivastava, Yintao Song, Kanwal Bhatti, R. D. James. The Direct Conversion of Heat to Electricity Using Multiferroic Alloys. Advanced Energy Materials, 2011; 1 (1): 97 DOI: 10.1002/aenm.201000048

Toward a 'green grid' for delivering solar and wind-based electricity

After years of neglect, scientists and policy makers are focusing more attention on developing technologies needed to make the so-called "green grid" possible, according to an article in ACS' Chemical Reviews. That's the much-needed future electrical grid, an interconnected network for delivering solar and wind-based electricity from suppliers to consumers.

Zhenguo (Gary) Yang and colleagues point out that concerns over the use of coal, oil, and other fuels that contribute to global warming and are in limited supply, have spurred interest in generating electrical energy from clean, renewable resources such as solar and wind power. But solar and wind are not constant and reliable sources of power, since wind power fluctuates from moment to moment and solar power is generated only in the daytime.

This situation poses a significant challenge for electrical grid operators because other power plants need to compensate for this variability and the U.S. power grid currently has little energy storage capability. To enable a significant level of penetration and effective use of renewable energy sources amid growing energy demands, electrical grids of the future will need a low-cost, efficient way to integrate and store this electrical energy, the scientists note.

The scientists analyzed the conclusions of more than 300 scientific studies and identified several technologies that can be used for energy storage for the green grid. These include high-tech batteries now in development that can efficiently store electricity in the form of chemicals and reversible release it on demand. Among the promising technologies are so-called redox flow and sodium-ion batteries, which could provide a low cost, high efficiency way to store energy.

In addition to the United States, several other countries such as China and countries in Europe are planning to increase research activities related to energy storage and development. "The growing interests as well as worldwide research and development activities suggest a bright outlook for developing stationary energy storage technologies for the future electric grid," the article concludes.

Provided by American Chemical Society (news : web)

New plastics can conduct electricity

 

(PhysOrg.com) -- A newly discovered technique makes it possible to create a whole new array of plastics with metallic or even superconducting properties.

Plastics usually conduct electricity so poorly that they are used to insulate electric cables but, by placing a thin film of metal onto a plastic sheet and mixing it into the polymer surface with an ion beam, Australian researchers have shown that the method can be used to make cheap, strong, flexible and conductive plastic films.

The research has been published in the journal ChemPhysChem by a team led by Professor Paul Meredith and Associate Professor Ben Powell, both at the University of Queensland, and Associate Professor Adam Micolich of the UNSW School of Physics. This latest discovery reports experiments by former UQ Ph.D. student, Dr Andrew Stephenson.

Ion beam techniques are widely used in the microelectronics industry to tailor the conductivity of semiconductors such as silicon, but attempts to adapt this process to plastic films have been made since the 1980s with only limited success – until now.

"What the team has been able to do here is use an ion beam to tune the properties of a plastic film so that it conducts electricity like the metals used in the electrical wires themselves, and even to act as a superconductor and pass electric current without resistance if cooled to low enough temperature," says Professor Meredith.

To demonstrate a potential application of this new material, the team produced electrical resistance thermometers that meet industrial standards. Tested against an industry standard platinum resistance thermometer, it had comparable or even superior accuracy.

"This material is so interesting because we can take all the desirable aspects of polymers - such as mechanical flexibility, robustness and low cost - and into the mix add good electrical conductivity, something not normally associated with plastics," says Professor Micolich. "It opens new avenues to making plastic electronics."

Andrew Stephenson says the most exciting part about the discovery is how precisely the film’s ability to conduct or resist the flow of electrical current can be tuned. It opens up a very broad potential for useful applications.

"In fact, we can vary the electrical resistivity over 10 orders of magnitude – put simply, that means we have ten billion options to adjust the recipe when we're making the plastic film. In theory, we can make plastics that conduct no electricity at all or as well as metals do – and everything in between,” Dr Stephenson says.

These new materials can be easily produced with equipment commonly used in the microelectronics industry and are vastly more tolerant of exposure to oxygen compared to standard semiconducting polymers.

Combined, these advantages may give ion beam processed polymer films a bright future in the on-going development of soft materials for plastic electronics applications – a fusion between current and next generation technology, the researchers say.

Provided by University of New South Wales (news : web)