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Wi-Charge Promises Phone Charging by Infrared Laser

In the world of wireless gadgets, charging is still a big problem Israeli startup Wi-Charge is looking to change that by allowing us constant wireless charging using infrared laser technology.

Broadly speaking you can divide wireless power technologies into two general categories: near field (a few centimeters or even physical contact) and far field (several meters or more). In the near field category there are quite a number of companies and several protocols including Qi, PMA/Rezence, and Open Dots all competing for close range wireless power delivery. All common commercial near field wireless power technologies today use either tightly coupled (inductive, physical contact between the transmitter and the receiver) or loosely coupled (resonant, with up to a few centimeters of distance). In both cases the transmitter and receiver need to be very close to each other.

Far field technologies on the other hand are still in their infancy, though some startups—such as uBeam and Energous—are promising big steps soon. For the most part all these approaches are limited in either distance or power, or both.

Wi-Charge believes its solution is different enough from its competitors to overcome their limits. Ortal Alpert, Wi-Charge's founder, had worked for years developing advanced optical storage solutions for his former startup. During this time he frequently travelled the globe on business, which forced him to constantly look for places to charge his mobile devices. Based on his experience as an optical engineer, he developed a new technology for wireless charging that uses infrared lasers and relies on two unique, and now patented, ideas.

To understand these ideas we first need to go back to the laser and how it works. A laser is usually described as a device that bounces light between a pair of mirrors on either end of a gain medium, which amplifies the light with each successive pass. Usually one of the mirrors inside this cavity is partially transparent allowing some of the light to exit as a laser beam.

Wi-Charge's ingenious idea was to take this cavity, which is typically a closed device, and turn it into an "open unit" where one of the mirrors is located for example in a light fixture on the ceiling and the other one on the receiving device. The semiconductor gain medium is located in the transmitter and provides the photons that are harvested by the photovoltaic cell at the receiver. 

Powerful lasers can be dangerous, however Wi-Charge uses a class 1 infra red laser (safe under all conditions of normal use) and more importantly the "external cavity" design means that the instant anything crosses the path of the laser—your hand, your eye—amplification will stop and the energy will drop.

The second unique idea has to do with being able to fix and maintain the connection between the transmitter and the receiver. Wi-Charge's design uses retro reflective mirrors instead of regular mirrors. These reflect light back to its source with minimum scattering. (You can sometimes find retro reflective mirrors on road signs and bicycles and a few were even left on the moon by the Apollo team.) Using retroreflectors makes aligning the mirrors unnecessary hence the beam is maintained even when the receiver is moving around—something demonstrated to us during a visit last year. During operation the transmitter continuously sends a very low power infrared signal across the room and when it hits the retro reflector on the receiver, the signal is returned and a connection is made and amplification begins. The connection will be maintained as long as it is in range and there is a line of sight.

Using a laser does have one distinct disadvantage–it requires a line of sight between the transmitter and the receiver. This means that you won't be able to charge your smartphone while it is in your pocket and instead need to put it face up on the table. According to Alpert, "we use our phones every 15 minutes on average, for Facebook, Twitter, Whatsapp, email and even for talking. It means that once we're seated for more than 15 minutes, the phone is usually out on the table— and ripe for wireless charging".

One of the big advantages of Wi-Charge's technology is its ability to deliver almost any amount of power, from few milliwatts for sensor powering to hundreds of watts used in industrial or even military applications. For the consumer market with devices such as smart phones and wearables, Wi-Charge is looking to start with a system capable of delivering 10 W.

Unlike other far field technologies, Wi-Charge has a pretty small footprint. A receiver can be as small as your phone's camera module and still charge from a distance of ten meters, Wi-Charge claims. For more power demanding applications and longer ranges both the transmitter and receiver will have to be larger, but not dramatically so. One potential application of the technology can be for powering a drone for border patrol or installation security. In this scenario a drone will receive power along its way from a transmitter mounted on a patrol car or on top of a building or tower from a distance of dozens or even hundreds of meters away and can stay in the air for countless hours or even days.

Laser power beaming isn't a new concept. Researchers from NASA's Marshall Space Flight Center and the University of Alabama powered a small-scale aircraft that flew solely by means of propulsive power from a ground-based 1-kw infrared laser back in 2003. Japan's Aerospace Exploration Agency (JAXA) presented an even more ambitious wireless power project in early 2015. Researchers from JAXA were able to deliver 1.8 kW "with pinpoint accuracy" to a receiving antenna 55 meters away, using carefully directed microwaves.

Seattle-based LaserMotive, which in 2006 won NASA's Power beam challenge is working on over the air as well as over fiber optic cable transfer of power to flying drones. Wi-Charge says it's inherent safety and small footprint would allow it to ground-power private and commercial drones in urban environment.

In a typical use case scenario, one transmitter in the ceiling (within a light fixture for example) will be able to charge up to four devices inside a room. In a demo that at Wi-Charge's offices in Rehovot, Israel, we saw a working prototype that included a transmitter in the ceiling and a smartphone with a special case containing a mirror and photovoltaic cell. It was able to charge from a distance of about 3 meters. The modified phone charged slower than if it had been plugged in to a wall socket, but according to Wi-Charge, the final product will be able to charge one smartphone at the same rate as a wired charger; though two devices will take longer. We were also shown a modified music player and speaker that worked without any batteries in the same way.

Alpert promises that the first product based on Wi-Charge's technology will be available in late 2016 and would be Internet-of-Things or smart home related. A year later the company is planning to release a residential mobile phone charging solution that will include a transmitter and phone case at the retail price of just under US $200. 

Smart Wearable Sensor Takes Sweat-Monitoring To Next Level

Sweat might not be pleasant but it contains dozens of chemical compounds whose concentrations change in real time, compounds that could reveal your body’s response to disease, drugs, diet, injury, and stress, among other things. To tap into that treasure-trove of information, researchers have built a wearable sensor that measures levels of specific molecules in sweat and then wirelessly relays the data to a smartphone via a Bluetooth module.

The smart device, fashioned as a wristband or headband, combines a panel of plastic chemical sensors with silicon integrated circuits made on a flexible circuit board. It continuously measures levels of four different components of sweat: two electrolytes, potassium and sodium ions, and two metabolites, glucose and lactate. Ali Javey, electrical engineering and computer sciences professor at the University of California, Berkeley and his colleagues reported the sensor in Nature.

Other research groups have demonstrated wearable sweat sensors before. But those measure one analyte at a time or don’t have the signal processing circuitry and calibration mechanism to accurately monitor analyte levels.

Javey and his colleagues built an array of chemical sensors, each 3-mm wide, on a flexible plastic substrate. The sensors are similar to ones reported before. They are based on enzymes or special chemical cocktails that react with the metabolite or ion to be measured and generate an electrical signal. But the researchers built on previous sensors by treating electrodes with specific added chemicals that reduce potential drift and make the new sensors more stable and reliable.

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Monster Machine Cracks the Game of Go

A computer program has defeated a master of the ancient Chinese game of Go, achieving one of the loftiest of the Grand Challenges of AI at least a decade earlier than anyone had thought possible.

The programmers, at Google’s Deep Mind laboratory, in London, write in today’s issue of Nature that their program AlphaGo defeated Fan Hui, the European Go champion, 5 games to nil, in a match held last October in the company’s offices. Earlier, the program had won 494 out of 495 games against the best rival Go programs.

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Roll to Roll Electronics Manufacturing Rolls On

Imagine a future where everything—your bed, your wallpaper, the box your cereal comes in—is capable of connecting to the Internet and the windows and walls of skyscrapers harvest energy from the sun. It’s a scenario many technologists talk about, but it would certainly strain today’s infrastructure for building silicon-based electronics. The future many depend on a more old-fashioned production process—roll-to-roll printing.

That, at least is what scientists and engineers argued at a session on the future of roll-to-roll processing at the Material Research Society’s fall meeting in Boston last month. Existing fabs and foundries produce about 20 billion silicon chips a year, far fewer than would be needed if the Internet of Everything is to become a reality, Donald Lupo, a professor of electronics and communications engineering at Tampere University of Technology in Finland, said at the meeting. Estimates hold that 50 to 200 billion objects will be connected to the Internet within five years, some with multiple devices on them, and many more coming in subsequent years, he added.

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Health Apps Study Raises Questions About Digital Medicine's Future

Smartphone apps designed to monitor patients with diabetes, high blood pressure, and heart disease may help reduce health care costs in the long run. But one of the most rigorous studies to date has found no big difference in health care costs for patients using mobile health apps and similar patients who did not rely on smartphone monitoring.

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Bitcoin Needs (Gasp!) Formal Governance

If you have even a casual interest in Bitcoin, then by now you probably know that on Friday developer Mike Hearn publicly declared the Bitcoin project a failure. And if you’ve followed Bitcoin over the years, then you also know this isn’t the first time the mourning bells are tolling. According to the scorekeepers, the count is now up to 89. 

This one, however, is different from the rest. The person throwing dirt over the coffin last week was not an outsider, as has most often been the case. It was not some mainstream economist who just “doesn’t get it.” It was not a misinformed journalist fishing for clicks. It was Mike Hearn, a former Google developer, the guy who wrote the first java implementation of Bitcoin. He’s a regular presence at conferences and a tireless educator of Bitcoin novices. And his most passionate vituperations were aimed at the people he is now leaving behind. Bitcoin failed, he wrote, “because the community has failed.”

Regardless of what you think about Mike Hearn and his assessment of Bitcoin’s woes, his words must be taken seriously, if only because there are plenty of other people out there who take his words seriously—enough, in fact, to inspire a 15 percent fall in the market price of Bitcoin on the day he published his diatribe.

The bulk of Hearn’s condemnation comes down to this: Bitcoin has a technical problem. It doesn’t scale and it’s finally reaching a level of adoption where this will soon  cause major disruptions in the speed and reliability of Bitcoin transactions. Some, including Hearn, say the technology has actually already reached the breaking point. 

Solutions have been proposed. But the developers responsible for making the decisions about what gets incorporated into the Bitcoin Core source code, who were at first slow even to proceed with a discussion, are now mired in stalemate over which option is best.

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NASA Picks Dream Chaser Shuttle for Space Station Resupply

A winged spacecraft that resembles a mini space shuttle will join the fleet of private rockets ferrying supplies to the International Space Station. NASA has announced that its new round of US $14 billion in commercial resupply contracts for the space station includes the Dream Chaser spacecraft made by the Sierra Nevada Corporation.

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Human Life Is a Gas

Changes in production of certain gases in the human gut have been linked to gastrointestinal disorders including painful constipation, irritable bowl syndrome (IBS), and colon cancer. Yet how and why this happens is not well understood. Without resorting to stressful invasive means, measuring and tracking gas concentrations in our stomachs and small and large intestines has to date been impractical.

That’s about to change. Researchers at RMIT University in Melbourne, Australia, have designed and custom-manufactured indigestible capsules that can measure the concentration of different gases during digestion in the gut of animals and humans—a world’s first, they claim. The capsules meet the standards necessary for such testing, and after conducting a series of trials on pigs, the researchers have begun recruiting human volunteers on which to test the next version of the pill.

An electronic capsule is composed of: an indigestible cladding; a gas-permeable membrane covering a sensor for detecting hydrogen, methane or carbon dioxide; a microcontroller; a 433-megahertz wireless transmitter; and four silver oxide batteries. The latest version of the capsule measures just 2.6 by 1.1 centimeters, which is “about the size of a 000 fish-oil capsule,” lead researcher Kourosh Kalantar-zadeh, a professor at RMIT’s Centre for Advanced Electronics and Sensors, told IEEE Spectrum.

“Nothing in the capsules is really expensive,” he added. “The batteries cost around $5 or $6 in total, as does the thermal-conductivity sensor, while the microcontroller is only 50 cents. We estimate the materials cost at $15, depending on component prices. This would come down with large scale production.”

The sensor data is transmitted straight from the gut to a custom-made coder-decoder unit that can be clipped onto a cellphone. The processed data is then sent to the phone for viewing via Bluetooth.

In one of the first animal trials, pigs—which have similar digestive systems to humans—were divided into two groups and fed the capsules along with high-fiber and low-fiber diets. The capsules sent data every five minutes and went into sleep mode between transmissions to conserve battery power. Minimum life of a battery was four days, more than long enough for a capsule to complete its job and be excreted by the pig.

“The data showed that a low-fiber diet produced four times more hydrogen in the small intestine than a high-fiber diet,” said Kalantar-zadeh. “This surprised us greatly, given that hydrogen is made through fermentation; we expected more fiber would produce more of the fermented gas.”

In addition, high-fiber diets produced more methane gas in the large intestine than the low-fiber diet, suggesting that painful gas retention could be avoided by reducing the intake of high-fiber foods. They found that the ratio of carbon dioxide and methane gases in the large intestine wasn’t affected by the amount of fiber the pigs consumed, suggesting that neither diet would help people suffering IBS problems associated with methane concentrations.

The implications of these findings, Kalantar-zadeh believes, could lead to “trashing misconceptions everyone has about certain kinds of food being good for certain conditions.”

The group’s research started in 2009, when the first capsule was produced. The newest capsule, Version 5, which will be used on human volunteers, will employ a temperature sensor and two gas sensors. One gas sensor will detect oxygen and hydrogen; the other is a hydrogen sensor that is not sensitive to oxygen but can also detect methane and carbon dioxide.

In conveying the importance of the research, Kalantar-zadeh explains that microorganisms form a significant part of our gut and work with us in symbiotic fashion. When they digest food and when they interact with each other, they produce gases. If they are healthy, they produce gases with normal profiles. If they are under stress or if there is any disorder, then the gas profiles change.

“This provides us with very good health biomarkers that no one has looked at before because they were hidden from sight inside our bodies. But now we have an easy means to measure gas concentrations in the gut.” Consequently, he says, this method can be used to build libraries of healthy gas profiles, against which the gas profiles of individuals can be compared.

The researchers are working on modifications aimed at further increasing the value of the data measured by the capsules. For instance, more sensors need to be included in a capsule to provide multi-gas measurements. They’re also seeking a way to precisely track the location of a capsule as it travels through the gut.

It’s only a matter of time, Kalantar-zadeh believes, before the technology will help medical researchers “design personalized diets and drugs that can target problem areas in the gut and help millions of people around the world affected by digestive disorders and diseases.”

Power Harvesting Sensor Patch Uses Your Body As a Battery

In theory, wearable electronics are great. In practice, they’re great—until you have to charge them, at which point they become annoying. We're counting on wireless power to come along and save us all, but in the meantime, there are other creative ways to keep lower power devices running. At CES last week, we saw a prototype of a wireless sensor patch that can monitor your hydration levels and send data to your phone, while getting all the power it needs from your own body heat.

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