Bacteria Use Brainlike Bursts of Electricity to Communicate


With electrical signals, cells can organize themselves into complex societies and negotiate with other colonies.
 

Bacteria have an unfortunate — and inaccurate — public image as isolated cells twiddling about on microscope slides. The more that scientists learn about bacteria, however, the more they see that this hermitlike reputation is deeply misleading, like trying to understand human behavior without referring to cities, laws or speech. “People were treating bacteria as … solitary organisms that live by themselves,” said Gürol Süel, a biophysicist at the University of California, San Diego. “In fact, most bacteria in nature appear to reside in very dense communities.”

The preferred form of community for bacteria seems to be the biofilm. On teeth, on pipes, on rocks and in the ocean, microbes glom together by the billions and build sticky organic superstructures around themselves. In these films, bacteria can divide labor: Exterior cells may fend off threats, while interior cells produce food. And like humans, who have succeeded in large part by cooperating with each other, bacteria thrive in communities. Antibiotics that easily dispatch free-swimming cells often prove useless against the same types of cells when they’ve hunkered down in a film.

As in all communities, cohabiting bacteria need ways to exchange messages. Biologists have known for decades that bacteria can use chemical cues to coordinate their behavior. The best-known example, elucidated by Bonnie Bassler of Princeton University and others, is quorum sensing, a process by which bacteria extrude signaling molecules until a high enough concentration triggers cells to form a biofilm or initiate some other collective behavior.

But Süel and other scientists are now finding that bacteria in biofilms can also talk to one another electrically. Biofilms appear to use electrically charged particles to organize and synchronize activities across large expanses. This electrical exchange has proved so powerful that biofilms even use it to recruit new bacteria from their surroundings, and to negotiate with neighboring biofilms for their mutual well-being.

“I think these are arguably the most important developments in microbiology in the last couple years,” said Ned Wingreen, a biophysicist who researches quorum sensing at Princeton. “We’re learning about an entirely new mode of communication.”

Biofilms were already a hot topic when Süel started focusing on them as a young professor recruited to San Diego in 2012. But much about them was still mysterious, including how individual bacteria give up their freedom and settle into large, stationary societies. To gain insight, Süel and his colleagues grew biofilms of Bacillus subtilis, a commonly studied rod-shaped bacterium, and observed them for hours with sophisticated microscopes. In time-lapse movies, they saw biofilms expand outward until cells in the interior consumed the available reserves of the amino acid glutamate, which the bacteria use as a nitrogen source. Then the biofilms would stop expanding until the glutamate was replenished. Süel and his colleagues became curious about how the inner bacteria were telling the outer cells when to divide and when to chill.

Quorum sensing was the obvious suspect. But Süel, who was trained in physics, suspected that something more than the diffusion of chemical messengers was at work in his Bacillus colonies. He focused on ion channels — specialized molecules that nestle into cells’ outer membranes and ferry electrically charged particles in and out. Ion channels are probably most famous for their role in nerve cells, or neurons. Most of the time, neurons pump out sodium ions, which carry a single positive charge, and let in a different number of potassium ions, also with single positive charges. The resulting charge imbalance acts like water piling up behind a dam. When an electrical impulse jolts a neuron’s membrane, specialized channels open to allow the concentrated ions to flood in and out, essentially opening the dam’s floodgates. This exchange propagates along the neuron, creating the electrical “action potentials” that carry information in the brain.

Süel knew that bacteria also pump ions across their membranes, and several recent papers had reported spikes of electrical activity in bacteria that at least loosely resembled those found in the brain. Could bacteria also be using the action-potential mechanism to transmit electrical signals? he wondered.

He and his colleagues treated biofilms in their lab with fluorescent markers that are activated by potassium and sodium ions, and the potassium marker lit up as ions flowed out of starved cells. When the ions reached nearby cells, those cells also released potassium, refreshing the signal. The signal flowed outward in this way until it reached the biofilm’s edge. And in response to the signal, edge cells stopped dividing until the interior cells could get a meal, after which they stopped releasing potassium.

Süel’s team then created mutant bacteria without potassium channels, and they found that the cells did not grow in the same stop-start manner. (The researchers also saw no movement of labeled sodium ions in their experiments.) Like neurons, bacteria apparently use potassium ions to propagate electrical signals, Süel and his colleagues reported in Nature in 2015.

Time-lapse video of two Bacillus subtilis biofilms in a shared environment shows their synchronized growth, which the bacteria coordinate through electrical communication. Green fluorescence reveals waves of released potassium ions that sweep through the biofilms as growth signals. In Süel’s experiment, when a nutrient is plentiful (left), the two biofilms grow at the same time. Their growth signals rise and fall in sync. When the nutrient is in short supply, the two biofilms “time-share” it for more efficient consumption by growing out of phase: each grows while the other is resting.

Time-lapse video of two Bacillus subtilis biofilms in a shared environment shows their synchronized growth, which the bacteria coordinate through electrical communication. Green fluorescence reveals waves of released potassium ions that sweep through the biofilms as growth signals. In Süel’s experiment, when a nutrient is plentiful (left), the two biofilms grow at the same time. Their growth signals rise and fall in sync. When the nutrient is in short supply, the two biofilms “time-share” it for more efficient consumption by growing out of phase: each grows while the other is resting.

Time-lapse video of two Bacillus subtilis biofilms in a shared environment shows their synchronized growth, which the bacteria coordinate through electrical communication. Green fluorescence reveals waves of released potassium ions that sweep through the biofilms as growth signals. In Süel’s experiment, when a nutrient is plentiful (left), the two biofilms grow at the same time. Their growth signals rise and fall in sync. When the nutrient is in short supply, the two biofilms “time-share” it for more efficient consumption by growing out of phase: each grows while the other is resting.

Adapted from Suel Lab at UCSD (Reference: J Liu et al. Science, 2017)

Despite the parallels to neural activity, Süel emphasizes that biofilms are not just like brains. Neural signals, which rely on fast-acting sodium channels in addition to the potassium channels, can zip along at more than 100 meters per second — a speed that is critical for enabling animals to engage in sophisticated, rapid-motion behaviors such as hunting. The potassium waves in Bacillus spread at the comparatively tortoise-like rate of a few millimeters per hour. “Basically, we’re observing a primitive form of action potential in these biofilms,” Süel said. “From a mathematical perspective they’re both exactly the same. It’s just that one is much faster.”

Bacterial Broadcasting

Süel and his colleagues had more questions about that electric signal, however. When the wave of potassium-driven electrical activity reaches the edge of a biofilm, the electrical activity might stop, but the cloud of potassium ions released into the environment keeps going. The researchers therefore decided to look at what happens once the potassium wave leaves a biofilm.

The first answer came earlier this year in a Cell paper, in which they showed that Bacillus bacteria seem to use potassium ions to recruit free-swimming cells to the community. Amazingly, the bacteria attracted not only other Bacillus, but also unrelated species. Bacteria, it seems, may have evolved to live not just in monocultures but in diverse communities.

A few months later, in Science, Süel’s team showed that by exchanging potassium signals, two Bacillus biofilms can “time-share” nutrients. In these experiments, two bacterial communities took turns eating glutamate, enabling the biofilms to consume the limited nutrients more efficiently. As a result of this sharing, the biofilms grew more quickly than they could have if the bacteria had eaten as much as they could without interruption. When the researchers used bacteria with ion channels that had been modified to give weaker signals, the biofilms, no longer able to coordinate their feeding, grew more slowly.

Süel’s discoveries about how bacteria communicate electrically have exhilarated bacteria researchers.

Moh El-Naggar, a biophysicist at the University of Southern California, investigates how bacteria exchange electrical signals through “nanowires.”

Moh El-Naggar, a biophysicist at the University of Southern California, investigates how bacteria exchange electrical signals through “nanowires.”

Allison V. Smith

“I think it’s some of the most interesting work going on in all of biology right now,” said Moh El-Naggar, a biophysicist at the University of Southern California. El-Naggar studies how bacteria transfer electrons using specialized thin tubes, which he calls nanowires. Even though this transfer could also be considered a form of electrical communication, El-Naggar says that in the past, he would “put the brakes on” if someone suggested that bacteria behave similarly to neurons. Since reading Süel’s 2015 paper, he’s changed his thinking. “A lot of us can’t wait to see what comes out of this,” he said.

For Gemma Reguera, a microbiologist at Michigan State University, the recent revelations bolster an argument she has long been making to her biologist peers: that physical signals such as light, sound and electricity are as important to bacteria as chemical signals. “Perhaps [Süel’s finding] will help the scientific community and [people] outside the scientific community feel more open about other forms of physical communication” among bacteria, Reguera said.

Part of what excites researchers is that electrical signaling among bacteria shows signs of being more powerful than chemically mediated quorum sensing. Chemical signals have proved critical for coordinating certain collective behaviors, but they quickly get diluted and fade out once they’re beyond the immediate vicinity of the bacteria emitting the signal. In contrast, as Süel’s team has found, the potassium signals released from biofilms can travel with constant strength for more than 1,000 times the width of a typical bacterial cell — and even that limit is an artificial upper bound imposed by the microfluidic devices used in the experiments. The difference between quorum sensing and potassium signaling is like the difference between shouting from a mountaintop and making an international phone call.

Moreover, chemicals enable communication only with cells that have specific receptors attuned to them, Wingreen noted. Potassium, however, seems to be part of a universal language shared by animal neurons, plant cells and — scientists are increasingly finding — bacteria.

A Universal Chemical Language

“I personally have found [positively charged ion channels] in every single-celled organism I’ve ever looked at,” said Steve Lockless, a biologist at Texas A&M University who was Süel’s lab mate in graduate school. Bacteria could thus use potassium to speak not just with one another but with other life-forms, including perhaps humans, as Lockless speculated in a commentary to Süel’s 2015 paper. Research has suggested that bacteria can affect their hosts’ appetite or mood; perhaps potassium channels help provide that inter-kingdom communication channel.The fact that microbes use potassium suggests that this is an ancient adaptation that developed before the eukaryotic cells that make up plants, animals and other life-forms diverged from bacteria, according to Jordi Garcia-Ojalvo, a professor of systems biology at Pompeu Fabra University in Barcelona who provided theoretical modeling to support Süel’s experiments. For the phenomenon of intercellular communications, he said, the bacterial channel “might be a good candidate for the evolutionary ancestor of the whole behavior.”

The findings form “a very interesting piece of work,” said James Shapiro, a bacterial geneticist at the University of Chicago. Shapiro is not afraid of bold hypotheses: He has argued that bacterial colonies might be capable of a form of cognition. But he approaches analogies between neurons and bacteria with caution. The potassium-mediated behaviors Süel has demonstrated so far are simple enough that they don’t require the type of sophisticated circuitry brains have evolved, Shapiro said. “It’s not clear exactly how much information processing is going on.”

Süel agrees. But he’s currently less interested in quantifying the information content of biofilms than in revealing what other feats bacteria are capable of. He’s now trying to see if biofilms of diverse bacterial species time-share the way biofilms of pure Bacillus do.

The view from above of a B. subtilis biofilm growing in culture. The varied structures within the biofilm relate to specialized functions that the cells in different parts of the biofilm assume.

The view from above of a B. subtilis biofilm growing in culture. The varied structures within the biofilm relate to specialized functions that the cells in different parts of the biofilm assume.

Hera Vlamakis, Harvard University Medical School

He also wants to develop what he calls “bacterial biofilm electrophysiology”: techniques for studying electrical activity in bacteria directly, the way neuroscientists have probed the brain for decades. Tools designed for bacteria would be a major boon, said Elisa Masi, a researcher at the University of Florence in Italy who has used electrodes designed for neurons to detect electrical activity in bacteria. “We are talking about cells that are really, really small,” she said. “It’s difficult to observe their metabolic activity, and there is no specific method” for measuring their electrical signals.

Süel and his colleagues are now developing such tools as part of a $1.5 million grant from the Howard Hughes Medical Institute, the Bill and Melinda Gates Foundation, and the Simons Foundation (which publishes Quanta).

The findings could also lead to new kinds of antibiotics or bacteria-inspired technologies, Süel said, but such applications are years away. The more immediate payoff is the excitement of once again revolutionizing our conceptions about bacteria. “It’s amazing how our understanding of bacteria has evolved over the last couple decades,” El-Naggar said. He is curious about how well potassium signaling works in complex, ion-filled natural settings such as the ocean. “Now we’re thinking of [bacteria] as masters of manipulating electrons and ions in their environment. It’s a very, very far cry from the way we thought of them as very simplistic organisms.”

“Step by step we find that all the things we think bacteria don’t do, they actually do,” Wingreen said. “It’s displacing us from our pedestal.”

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German student creates electromagnetic harvester that gathers free electricity from thin air


A German student has built an electromagnetic harvester that recharges an AA battery by soaking up ambient, environmental radiation. These harvesters can gather free electricity from just about anything, including overhead power lines, coffee machines, refrigerators, or even the emissions from your WiFi router or smartphone.

This might sound a bit like hocus-pocus pseudoscience, but the underlying science is actually surprisingly sound. We are, after all, just talking about wireless power transfer — just like the smartphones that are starting to ship with wireless charging tech, and the accompanying charging pads.

Dennis Siegel, of the University of Arts Bremen, does away with the charging pad, but the underlying tech is fundamentally the same. We don’t have the exact details — either because he doesn’t know (he may have worked with an electrical engineer), or because he wants to patent the idea first — but his basic description of “coils and high frequency diodes” tallies with how wireless power transfer works. In essence, every electrical device gives off electromagnetic radiation — and if that radiation passes across a coil of wire, an electrical current is produced. Siegel says he has produced two versions of the harvester: One for very low frequencies, such as the 50/60Hz signals from mains power — and another for megahertz (radio, GSM) and gigahertz (Bluetooth/WiFi) radiation.

The efficiency of wireless charging, however, strongly depends on the range and orientation of the transmitter, and how well the coil is tuned to the transmitter’s frequency. In Siegel’s case, “depending on the strength of the electromagnetic field,” his electromagnetic harvester can recharge one AA battery per day. He doesn’t specify, but presumably one-AA-per-day is when he’s sitting next to a huge power substation. It makes you wonder how long it would take to charge an AA battery via your coffee machine, or by leeching from your friend’s mobile phone call.

Energy harvester, gathering power from a coffee machine's ambient electromagnetic radiationAs a concept, though, Siegel’s electromagnetic harvester is very interesting. On its own, a single harvester might not be all that interesting — but what if you stuck a bunch of them, magnetically, to various devices all around your house? Or, perhaps more importantly, why not use these harvesters to power tiny devices that don’t require a lot of energy? Sensors, hearing aids (cochlear implants), smart devices around your home — they could all be powered by harvesting small amounts of energy from the environment.

One question does remain, though: How much ambient, wasted electromagnetic radiation is actually available? There are urban legends about people who install coils of wire in their garage, and then suck up large amounts of power from nearby power substations or radio transmitters. Would the power/radio company notice? Would it degrade the service for other people? Is this a likely plot for Die Hard 6: A better day to die hard?

Working up a sweat could soon power your Fitbit: Researchers design patch that converts body heat into electricity


 

  • New 2mm thick patches convert body heat into electricity
  • Layer of thermally conductive material sits on skin and spreads out heat
  • Polymer layer on top forces heat into device that makes electricity
  • Found the optimal place to harvest body heat is on the upper arm
  • Researchers have also incorporated the patch into T-shirts 

Soon working up a sweat won’t just increase your heart rate on your Fitbit – it will also power the device.

Researchers are currently developing a new design that harvests body heat and converts it into electricity that can power wearables and smartphones.

The system uses a body-conforming patch with a conductive layer that forces body heat through a centrally-located wearable thermoelectric generator, where it is converted into electricity.

This innovation derives from North Carolina State University, who states their prototype can generate far more electricity than previous lightweight heat harvesting technologies – 20 μW per centimeter squared, compared to 1 microwatt or less.

‘Wearable thermoelectric generators (TEGs) generate electricity by making use of the temperature differential between your body and the ambient air,’ says Daryoosh Vashaee, an associate professor of electrical and computer engineering at NC State and corresponding author of a paper on the work.

‘Previous approaches either made use of heat sinks – which are heavy, stiff and bulky – or were able to generate only one microwatt or less of power per centimeter squared (µW/cm2).’

‘Our technology generates up to 20 µW/cm2 and doesn’t use a heat sink, making it lighter and much more comfortable.’

The team began with a layer of thermally conductive material that rests on the skin and spreads out the heat.

A polymer layer was then placed on top to prevent heat from escaping from the body.

This components also forces the body heat to pass through a centrally-located TEG that is one cm2.

Heat that is not converted into electricity passes through the TEG into an outer layer of thermally conductive material, which rapidly dissipates outside the body.

The team began with a layer of thermally conductive material that rests on the skin and spreads out the heat. A polymer layer was then placed on top to prevent heat from escaping the body, this forces the body heat to pass through a centrally-located TEG that is one cm2 

The team began with a layer of thermally conductive material that rests on the skin and spreads out the heat. A polymer layer was then placed on top to prevent heat from escaping the body, this forces the body heat to pass through a centrally-located TEG that is one cm2

This new system is just 2 millimeters thick and the team says it is also very flexible.

‘In this prototype, the TEG is only one centimeter squared, but we can easily make it larger, depending on a device’s power needs,’ says Vashaee, who worked on the project as part of the National Science Foundation’s Nanosystems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST) at NC State.

While creating this new power generator, the team discovered that the upper arm is the optimal location for harvesting heat.

TURN YOURSELF INTO A WALKING CHARGER

Researchers at the Massachusetts Institute of Technology have developed a button sized self-charging battery that can scavenge energy from low temperature sources of heat.

The device can charge itself at temperatures between 20°C(68°F) and 60°C (140°F), far lower than other heat-harvesting technologies.

The button sized battery designed by Dr Gang Chen and his team at the Massachusetts Institute of Technology is a prototype for a new way of charging mobile devices from surrounding heat

The button sized battery designed by Dr Gang Chen and his team at the Massachusetts Institute of Technology is a prototype for a new way of charging mobile devices from surrounding heat

Dr Gang Chen, head of the mechanical engineering department at MIT, who led the work, said the technology could lead to new mobile phone batteries that can be charged without needing to be plugged in.

The two centimetre wide battery works by exploiting the relationship between temperature and voltage known as the thermally regenerative electrochemical cycle.

This cycle means that a battery charged at high temperatures can deliver more electricity at lower temperatures than has been used to charge it in the first place because of the energy absorbed as heat.

Dr Chen and his colleagues found they use this to create a ‘heat engine’ to generate electricity purely from the heat surrounding the battery.

By tuning the battery’s electrodes, which were made from lead and ionic iron, Dr Chen and his colleagues were able to produce a device that could achieve this at low temperatures.

This they believe, would allow a phone to be charged by harvesting energy from body heat and then cooling down when it is removed from a pocket.

While the skin temperature is higher around the wrist, the irregular contour of the wrist limited the surface area of contact between the TEG band and the skin.

They also found that wearing the band on the chest limits air flow, as the chest is normally covered by a shirt.

In addition, the researchers incorporated the TEG into T-shirts.

The researchers found that the T-shirt TEGs were still capable of generating 6 µW/cm2 – or as much as 16 µW/cm2 if a person is running.

This new system is also just 2 millimeters and the team says it is also very flexible. In addition, the researchers incorporated the TEG into T-shirts (pictured)

This new system is also just 2 millimeters and the team says it is also very flexible. In addition, the researchers incorporated the TEG into T-shirts .

‘T-shirt TEGs are certainly viable for powering wearable technologies, but they’re just not as efficient as the upper arm bands,’ Vashaee said.

‘The goal of ASSIST is to make wearable technologies that can be used for long-term health monitoring, such as devices that track heart health or monitor physical and environmental variables to predict and prevent asthma attacks,’ he says.

‘To do that, we want to make devices that don’t rely on batteries. And we think this design and prototype moves us much closer to making that a reality.’

 

Tesla’s home battery pack that could ‘change the way the world uses energy’: Elon Musk unveils $3,000 device that can power an entire home for eight hours


 

  • Musk unveiled Powerwall device at press conference in California
  • Daily use version will be able to store 7 kilowatt-hours of electricity 
  • It will let users store renewable energy, or pay lower, off-peak rates
  • Also revealed a larger model which is a ‘infinitely scalable system’ 

 

Tesla founder Elon Musk has unveiled a ‘revolutionary’ $3,000 (£1,980) battery which he claims can run an entire home for eight hours.

Musk introduced the Powerwall device at a press conference in California last night and said the technology could ‘change the world’.

The device, which could be in homes by the end of summer, will be able to store electricity at night when it is cheaper.

Tesla has unveiled a 'revolutionary' $3,000 (£1,980) home battery that can power an entire house for eight hours

Tesla has unveiled a $3,000 (£1,980) home battery that can power an entire house for eight hours. Powerwall is three feet wide and four feet tall, weighs 220lbs, and can be installed on an outside or inside wall

Tesla has unveiled a $3,000 (£1,980) home battery that can power an entire house for eight hours. Powerwall is three feet wide and four feet tall, weighs 220lbs, and can be installed on an outside or inside wall. The left images shows the 10kWh version while on the right is the 7kWh device

HOW DOES POWERWALL WORK?

The technology powers up overnight when electricity rates are cheaper. Users can then switch the battery on during the day to use the home during the day.

Powerwall can be used as back up power in the case of an emergency, or be used to hold power from renewable energy sources.

The ‘daily use’ version has a capacity of 7 kilowatt-hours, which is around a quarter of a home’s daily usage. The  average U.S. home uses 10,908 kilowatt-hours of energy per year, or just short of 30 per day.

Home battery packs could disrupt the utility market. In 2013, the Edison Electric Institute, the trade group for investor-owned electric companies, issued a report warning about disruption.

‘One can imagine a day when battery storage technology or micro turbines could allow customers to be electric grid independent,’ the report said.

It would then discharge this cheap electricity during the day in quantities large enough to be useful to homes and businesses.

The  Powerwall is around three feet wide and four feet tall, weighs 220lbs, and can be installed either on an outside or inside wall of a home.

The ‘daily use’ version has a capacity of 7 kilowatt-hours, which is around a quarter of a home’s daily usage.

Department of Energy figures state that the average U.S. home uses 10,908 kilowatt-hours of energy per year, or just short of 30 per day.

According to that figure, a single, fully-charged Powerwall device would be able to meet a quarter of a home’s energy needs on any given day.

However, it would likely last far less time than eight hours during the mornings and evenings, when homes use the vast majority of their electricity.

Musk said that the devices can be stacked together to provide more energy.

The system would let homeowners with solar panels or other sources of renewable energy easily store their energy at home, rather than the current model whereby they sell power back to energy suppliers as it is produced, then buy it again during peak times.

It could also let savvy consumers take advantage of power companies’ lower rates during the night and use the cheaper, stored energy during peak periods.

According to tech site Mashable, Musk told attendees at the event: ‘Our goal is to fundamentally change the way the world uses energy.

Tesla unveils batteries for homes to store solar energy

Pictured is a utility-scale version of Powerwall that can be used by businesses and scaled up for more power

Pictured is a utility-scale version of Powerwall that can be used by businesses and scaled up for more power

The 'daily use' version has a capacity of 7 kilowatt-hours, which is around a quarter of a home's daily usage

The ‘daily use’ version has a capacity of 7 kilowatt-hours, which is around a quarter of a home’s daily usage

WHAT IS THE POWERPACK?

Tesla also unveiled the ‘Powerpack’, which is the big brother of the Powerwall.

It describes it as an ‘infinitely scalable system’ that can work for businesses, in industrial applications, and public utility companies.

It comes in 100 kWh battery blocks that can scale from 500 kWH all the way up to 10 MWh.

 ‘Our goal here is to change the way the world uses energy at an extreme scale,’ it said.

‘It sounds crazy, but we want to change the entire energy infrastructure of the world to zero carbon.’

As well as the daily-use model, Tesla will also launch a 10 kilowatt-hour backup battery, designed to tide homes over during power blackouts, such as those caused by storms.

Marketing material for the device, published late Thursday on Tesla’s website, says: ‘Powerwall is a home battery that charges using electricity generated from solar panels, or when utility rates are low, and powers your home in the evening.

‘It also fortifies your home against power outages by providing a backup electricity supply.

‘Automated, compact and simple to install, Powerwall offers independence from the utility grid and the security of an emergency backup.’

Musk said that he hopes to sell hundreds of millions of the devices, which he touted as a vast improvement over currently-available models. In the past he has said such early batteries ‘suck’.

He later added that the entire showcase had been powered by a huge array of Powerwall batteries.

Pictured is the 'powerpack', an 'infinitely scalable system' that comes in 100 kWh battery blocks that can scale from 500 kWH all the way up to 10 MWh and higher
Pictured is the 'powerpack', an 'infinitely scalable system' that comes in 100 kWh battery blocks that can scale from 500 kWH all the way up to 10 MWh and higher

Pictured is the ‘powerpack’. Elon Musk (right) describes it as an ‘infinitely scalable system’ that comes in 100 kWh battery blocks that can scale from 500 kWH up to 10 MWh and higher

The technology could let savvy consumers take advantage of power companies' lower rates during the night and use the cheaper, stored energy during peak periods.  Mr Musk is already the chairman of SolarCity - a company that offers solar power systems for homes - and Tesla's home battery is an extension of this

The technology could let savvy consumers take advantage of power companies’ lower rates during the night and use the cheaper, stored energy during peak periods.  Mr Musk is already the chairman of SolarCity – a company that offers solar power systems for homes – and Tesla’s home battery is an extension of this

Musk said that he hopes to sell hundreds of millions of the devices, which he touted as a vast improvement over currently-available models. In the past he has said such early batteries 'suck'

Musk said that he hopes to sell hundreds of millions of the devices, which he touted as a vast improvement over currently-available models. In the past he has said such early batteries ‘suck’

Tesla also unveiled the ‘Powerpack’, which is the larger scale version of the Powerwall.

It describes it as an ‘infinitely scalable system’ that can work for businesses, in industrial applications and public utility companies.

It comes in 100 kWh battery blocks that can scale from 500 kWH all the way up to 10 MWh.  ‘Our goal here is to change the way the world uses energy at an extreme scale,’ it said.

The latest announcement builds on previous Tesla products, principally its range of cars.

Last year, Tesla Motors unveiled plans for a ‘Gigafactory’ designed to help the firm ramp up production of batteries for its electric cars, and now homes.

Tesla said the factory will cut current battery production costs by up to 30 per cent, and will be powered predominantly by renewable energy sources, such as wind and solar.

Elsewhere, Mr Musk is already the chairman of SolarCity – a company that offers solar power systems for homes – and Tesla’s home battery could be an extension of this.

These batteries 3ft tall (0.9 metres), and can be controlled remotely using a smartphone app. Tesla would not comment on whether the new batteries will work in the same way.

Home battery packs could disrupt the utility market. In 2013, the Edison Electric Institute, the trade group for investor-owned electric companies, issued a report warning about disruption.

Powerwall charges using electricity generated from solar panels, or when utility rates are low, and powers your home in the evening

Powerwall charges using electricity generated from solar panels, or when utility rates are low, and powers your home in the evening

Tesla reveals plans to build $5B ‘gigafactory’ in Nevada

‘One can imagine a day when battery storage technology or micro turbines could allow customers to be electric grid independent,’ the report said.

Deutsche Bank estimates sales of stationary battery storage systems for homes and commercial uses could yield as much as $4.5 billion in revenue for Tesla.

Analysts expect Tesla will build stationary storage systems around the same basic batteries it will produce for its vehicles at a large factory the company is building in Nevada.

Stationary storage systems could be part of a fossil-fuel free lifestyle in which an individual has solar panels on the roof, generating electricity that can power home appliances and recharge batteries in a Tesla Model S sedan parked in the garage.

Government subsidies and a dramatic drop in the price of lithium ion batteries are drawing more companies into the home electricity storage business.

Tesla has so far received $1.1 million from California’s Self-Generation Incentive Program. Tesla has received or is poised to receive state funding for about 600 storage projects in California, according to data from the state.

Though valued at just $200 million in 2012, the energy storage industry is expected to grow to $19 billion by 2017, according to research firm IHS CERA.

In Tesla's view, such storage systems could become part of a fossil-fuel-free lifestyle in which people can have solar panels on their roof generating electricity to power their home and recharge their electric car batteries

In Tesla’s view, such storage systems could become part of a fossil-fuel-free lifestyle in which people can have solar panels on their roof generating electricity to power their home and recharge their electric car batteries

 

 

New fabric turns your body into a furnace


The future of winter clothes has arrived, and it’s even better than wrapping yourself in an electric blanket until spring. Researchers have created a new cloth that warms up with just a bit of electricity and traps body heat more efficiently than standard cotton fabric.

New fabric turns your body into a furnace

The scientists dipped ordinary cotton cloth in a solution of silver nanowire particles, which form a conductive network embedded in the cloth. By varying the concentration of the solution, the researchers were able to control the particles’ spacing in the network, ultimately finding the sweet spot where the fabric trapped close to 80% of the heat our bodies radiate while still allowing water molecules to pass through, they will report this month in Nano Letters. That retains the breathability of the material, making it possible to create comfortable winter clothes out of the new fabric. For extra-cold days, electricity can provide an additional boost: The cloth warms up to nearly 40°C when powered with a mere 0.9 volts of electricity. Wearing such toasty clothes could help reduce the energy we spend on wasteful residential heating, the researchers say. They estimate that a person requiring indoor heat during a period of 4 months with average outdoor temperatures at about 10°C could save 1000 kilowatt hours of energy per year, or roughly 300 liters of gas, just by wearing a nanocloth sweater at home.

How to Cool Buildings Without Electricity? Beam Heat into Space


A new superthin material can cool buildings without requiring electricity, by beaming heat directly into outer space, researchers say.

In addition to cooling areas that don’t have access to electrical power, the material could help reduce demand for electricity, since air conditioning accounts for nearly 15 percent of the electricity consumed by buildings in the United States.

Cooling Buildings Without Electricity

The heart of the new cooler is a multilayered material measuring just 1.8 microns thick, which is thinner than the thinnest sheet of aluminum foil. In comparison, the average human hair is about 100 microns wide. [Top 10 Craziest Environmental Ideas]
This material is made of seven layers of silicon dioxide and hafnium dioxide on top of a thin layer of silver. The way each layer varies in thickness makes the material bend visible and invisible forms of light in ways that grant it cooling properties.

Invisible light in the form of infrared radiation is one key way all objects shed heat. “If you use an infrared camera, you can see we all glow in infrared light,” said study co-author Shanhui Fan, an electrical engineer at Stanford University in California.

One way this material helps keep things cool is by serving as a highly effective mirror. By reflecting 97 percent of sunlight away, it helps keep anything it covers from heating up.

In addition, when this material does absorb heat, its composition and structure ensure that it only emits very specific wavelengths of infrared radiation, ones that air does not absorb, the researchers said. Instead, this infrared radiation is free to leave the atmosphere and head out into space.

“The coldness of the universe is a vast resource that we can benefit from,” Fan told Live Science.

The scientists tested a prototype of their cooler on a clear winter day in Stanford, California, and found it could cool to nearly 9 degrees Fahrenheit (5 degrees Celsius) cooler than the surrounding air, even in the sunlight.

“This is very novel and an extraordinarily simple idea,” Eli Yablonovitch, a photonics crystal expert at the University of California, Berkeley, who did not take part in this research, said in a statement.

The researchers suggested that their material’s cost and performance compare favorably to those of other rooftop air-conditioning systems, such as those driven by electricity derived from solar cells. The new device could also work alongside these other technologies, the researchers said.

However, the scientists cautioned that their prototype measures only about 8 inches (20 centimeters) across, or about the size of a personal pizza. “We are now scaling production up to make larger samples,” Fan said. “To cool buildings, you really need to cover large areas.”

Dot Physics The Physics of Wireless Charging


What if you could charge your phone (or device) without having to worry about the charging cable? Well, you can. This is the idea behind wireless charging. In short, you place your device on some type of pad and then phone gets power without a wire (as long as the phone also supports wireless charging). That’s where they get the term “wireless charging” – you know…because there are no wires.

Magnets and Wires

Let’s start with a very simple demonstration. Here I have a coil of wire connected to a Galvanometer. I could write a whole post on just the Galvanometer, but for now I will just say that it measures electric current. Inside the red coil I am holding a very strong magnet.

Summer 14 Sketches key

If I just hold the magnet inside the coil, nothing happens. However, if I move the magnet either in or out of the coil I get a current.

Wireless

This is all about changing magnetic flux. Yes, just like a “flux capacitor” even though that isn’t a real thing. You can have flux for all sorts of things. My favorite flux to use as an example is rain flux. This is simply the rate that falling rain hits some area – let’s say it’s a sheet of paper.

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There are three things you could change that would also change this “rain flux”. First, you could change how much it rains. If the rain comes down faster of course more water will hit the paper (note – real rain drops aren’t shaped like that). Second, you could change the angle between the paper and the rain. Third, you could change the area of paper. That’s rain flux.

We can do the exact same thing with the magnetic field. Guess what we call this? Yes, it’s called the magnetic flux. This magnetic flux depends on the strength of the magnetic field, the angle between the field and the area and the size of the area.

Summer 14 Sketches key

The curved lines are representations of the magnetic field from the magnet.

Here is the physics part. When you change the magnetic flux, you create an electric field inside the wire. This electric field then makes an electric current and electric currents can recharge your phone. Remember, CHANGE in flux is the important part. Actually, you could just use a spinning magnet and a coil of wire and make as much electricity as you want. In fact, this is exactly what happens with a gasoline powered generator. Oh, it’s also how a nuclear power plant makes electricity (the nuclear reactions just turn water to steam and the steam turns a turbine).

Magnetic Flux Without Magnets

The wireless chargers don’t have magnets in them. If you place a wire with current over a magnetic compass you can see that these currents also make magnetic fields.

The Physics of the Railgun   Science Blogs   Wired

If you replace a moving magnet with a wire that has alternating current, you are all set. The changing electric current in one wire makes a changing magnetic field. This changing magnetic field then induces an electric current in another loop. Also, the more loops you have (in both coils of wires) the greater the effect. Here is simplest version of wireless charging.

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On the bottom is a huge coil of wire. This wire is then attached to a household style plug. Yes, it’s just a loop of wire with a plug on the end. When you plug this thing into the outlet, electric current runs through the wire. All the outlets in your house have alternating current. This means the current oscillates with a 60 Hz frequency and provides the changing current needed to make a changing magnetic field. On top of this large coil is a smaller coil (in my hand). This coil is just connected to a small lightbulb. When this small lightbulb-coil is near the changing magnetic field, you get an induced current. The current is large enough to light up the lightbulb.

Of course, an actual wireless charger is a little bit smaller – but same idea.

Last question. Previously, I looked at the possibility of charging a smartwatch just by shaking it. Could you power a smartwatch with a wireless charger? Yes, you could. However, the smart watch would have to be right on the charger. It wouldn’t work over a long distance – at least not with this type of wireless charger.

Waking Up Tired? Blame Electricity.


Our internal clocks are drifting out of sync, and indoor lighting may be to blame. A new study suggests that just a few days in the great outdoors puts us back in tune with the solar cycle, and reconnecting with the sun could make us less drowsy.

Electricity has given us the freedom to choose our bedtimes; staying up after dark is as easy as flipping a light switch. But we pay a price for this luxury, says integrative physiologist Kenneth Wright of the University of Colorado, Boulder, who led the new study. People with later bedtimes and wake times are exposed to more artificial light and less sunlight, he says, which means their bodies aren’t getting the natural cues humans once relied on.

sn-camping

To understand how falling out of sync with the sun changes our body’s internal clock—or circadian rhythm—sleep researchers look to the timekeeping mechanisms in the brain, particularly how we regulate the hormone melatonin. Released about 2 hours before sleep, melatonin makes us feel drowsy as we wind down for rest, Wright says. It then decreases as we become alert in the morning. The mechanisms driving our clock are complex and hard to measure, but the daily spike and drop in melatonin are like its chimes. “Melatonin tells us what time it is in the body,” Wright says.

And when we keep strange schedules, our melatonin goes haywire. Turning lights on at night can delay melatonin release and shift the timing of our internal clock, says sleep physiologist Derk-Jan Dijk of the University of Surrey in the United Kingdom, who was not involved in the work. But it wasn’t clear just what would happen in modern, electricity-adapted humans if all artificial light were suddenly taken away. “This is the first time that somebody has done the obvious but important experiment,” he says.

Wright and his colleagues outfitted eight subjects with activity-tracking watches that carry light intensity detectors and motion sensors to keep tabs on sleep and wake times. For the first week, the participants went about their lives, spent mostly in artificially lit buildings. They then spent 24 hours in a lab, where the researchers periodically tested the melatonin levels in their saliva. In the second week, the group went camping in the Colorado Rockies, where they could sleep and wake up whenever they wanted but had no access to TV, cell phones, or even flashlights. Their world was illuminated only by sunlight and campfires. The group returned from their excursion for another stint of saliva sampling.

Data from the watches showed that subjects got about the same amount of sleep in the two settings. But the shift from artificial to natural light, which nearly quadrupled their total light exposure, also tinkered with their internal clocks. After camping, the subject’s biological cycles had shifted to align with the sun. Their bodies released melatonin right at sunset—2 hours earlier than under artificial light conditions—and shut it off again just after sunrise, the team reports online today in Current Biology.

“When we expose ourselves to only natural light, we are in sync with that light-dark cycle quite strongly,” Wright says. The natural night owls in the group saw an especially dramatic shift in their melatonin cycle and became more similar to the early birds. The team suggests that artificial light had been exerting a particularly strong influence on the internal clocks of the night owls. The subjects weren’t asked to report whether they felt less drowsy after the change in lighting.

Observing changes in human rhythms in a natural environment represents a “breakthrough,” says Marie Dumont, a chronobiologist at the University of Montreal in Canada. “I think we forget most of the time that the knowledge that we have comes from laboratory and artificial conditions,” she says. Dumont cautions, however, that few conclusions can be drawn from this small group of individuals. Changes in physical activity during the camping trip and the social interaction subjects had also likely influenced the retiming of their internal clocks, she says.

But the work may offer clues about the tiredness that plagues many night owls. Other studies have shown that our low point in alertness, when melatonin production is shutting off in the morning, tends to occur about 2 hours after awakening. “We wake up, but then our clock still promotes sleepiness, and we don’t feel well,” explains Dijk, whose research group first described this unfortunate paradox. After the week of camping, participants’ melatonin shutoff occurred before they awoke instead of after. Wright says that the discrepancy between our melatonin cycle and our sleep-wake cycle could account for our morning sleepiness—an explanation Dijk calls “an interesting suggestion” that needs more thorough study.

Because we’re not going to abandon our electrified existence anytime soon, Wright says that certain habits can counteract our estrangement from the sun. He recommends letting plenty of light into your room in the morning, exposing yourself to more natural light throughout the day, and dimming the lighting in your home a couple hours before bed. Now have a good night.

Soure: BIOLOGY

 

 

 

New way to predict power faults.


Melbourne researchers have invented and patented a way of detecting and locating potential electrical faults along large stretches of power line before they occur.

The invention was inspired by a boyhood interest in electric fishes, such as the black ghost knifefish.

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The patented detection system, already being employed by local electricity companies, could help prevent the major discharges that lead to sparking and blackouts, says Dr. Alexe Bojovschi, a post-doctoral fellow in electrical and computer engineering at RMIT University.

“Internationally, this is very important. Last year, blackouts left 620 million people in India without power for a couple of days and cost the US economy more than US$120 billion. Electric sparking has been blamed for major bushfires in Australia.”

Alexe is one of 12 early-career scientists unveiling their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Australian Government through the Inspiring Australia initiative.

He says he got the idea on how the electromagnetic signatures of potential faults could travel in the power networks from the ability of electric fishes to transmit and receive electromagnetic radiation.

Our power networks, many of which were built at least 50 years ago, are ageing and deteriorating just at the time when they are being overloaded with new appliances, Alexe says. “All it takes is a salt deposit or a build-up of lichen to provide a conductive path on an insulator, and you enhance the likelihood of electrical discharges.”

The patented wireless sensing technology can be mounted to the power poles to detect the discharge signature in the power network. The sensors can be used to locate the fault point by translating the time of arrival of the signature into a measure of distance.

Alexe and his project managers Associate Professors Alan Wong and Wayne Rowe have established a company, IND Technology (www.ind-technology.com.au), to commercialise the system.

At present, IND Technology is offering the technology as an early-fault-detection service to electricity companies in Victoria online 24 hours a day. “The system provides a dynamic picture of the health of their power networks,” Alexe says. “But this is a worldwide issue, so the company has the potential to expand globally.”

Source: http://www.sciencealert.com.au

Heartbeat ‘could power pacemaker.


A device which could harness energy from a beating heart can produce enough electricity to keep a pacemaker running, according to US researchers.

Repeated operations are currently needed to replace batteries in pacemakers.

Tests suggested the device could produce 10 times the amount of energy needed.

The British Heart Foundation said clinical trials were needed to show it would be safe for patients.

Piezoelectric materials generate an electric charge when their shape is changed. They are used in some microphones to convert vibrations into an electrical signal.

Researchers at the University of Michigan are trying to use the movement of the heart as a source of electricity.

In tests designed to simulate a range of heartbeats, enough electricity was generated to power a pacemaker. The designers now want to test the device on a real heart and build it into a commercial pacemaker.

Dr Amin Karami told a meeting of the American Heart Association that pacemaker batteries needed to be replaced approximately every seven years.

“Many of the patients are children who live with pacemakers for many years. You can imagine how many operations they are spared if this new technology is implemented.”

Prof Peter Weissberg, the medical director at the British Heart Foundation, said: “Advancing technology over recent years has meant people with pacemakers need to change their battery less often. This device could be another step forward along this path.

“If researchers can refine the technology and it proves robust in clinical trials, it would further reduce the need for battery changes.”

Source:BBC