Tunable electric eyeglasses bend to the will of the wearer

Three electronically controlled mechanical actuators bend each liquid lens of the smart glasses to change focus.

Credit: Carlos H. Mastrangelo, University of Utah

Engineers have developed glasses with liquid-based lenses that “flex” to refocus on whatever the wearer is viewing.

Engineers funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) have developed glasses with liquid-based lenses that "flex" to refocus on whatever the wearer is viewing.

The adjustable "smart glasses" were developed by a University of Utah team led by electrical and computer engineering professor Carlos H. Mastrangelo, Ph.D., and his doctoral student Nazmul Hasan. The work is reported in the January 17 issue of Optics Express.

"The glasses incorporate an impressive array of electrical, mechanical, optical, sensor, and computer technologies with the goal of developing a one-size-fits-all approach to vision correction," said Andrew Weitz, Ph.D., NIBIB program director, whose expertise includes bioelectronic vision technologies.

The glasses are designed to mimic the behavior of the eye's natural lens -- flexing to focus on wherever an individual is looking: near, far or in-between. Unfortunately for many of us, as we age our lenses become stiffer and lose the ability to bend enough to focus at different distances.

Standard glasses compensate for the bend our ageing eyes can no longer achieve to focus. This becomes more complicated if we are unable to focus at multiple distances, which necessitates glasses with multiple lenses for different distances, such as bifocals, trifocals or progressive lenses, which must be regularly replaced as our eyesight changes.

The central technology of the glasses created by the research team are lenses made of glycerin, a clear thick liquid sandwiched between flexible membranes. The lenses are mounted into frames that have an electromechanical system that causes the membranes to bend to adjust their focus. The ability of the lens to flex and bend allows the single lens to act like multiple lenses.

The glasses are designed to work for most people at a wide range of distances due to a sophisticated computer algorithm that works with two critical variables. One is the eyeglass prescription that the user enters into the system using an attached mobile app. The other is where the user is looking -- specifically how far away. This information is provided by a sensor mounted in the bridge of the glasses that uses pulses of infrared light to identify where the user is looking and provide the precise distance.

The combination of the user's prescription information and the distance information is used by the algorithm to instantly adjust the shape of the liquid lenses to allow the user to focus on what they are viewing. Remarkably, if the user looks elsewhere, the change in lens shape needed to focus at the new distance is made in a staggering 14 milliseconds -- 25 times faster than an eye blink.

"Theoretically, these would be the only glasses a person would ever have to buy because they can correct the majority of focusing problems," says Mastrangelo. "Users just have to input their new prescription as their eyesight changes."

Because they house a lot of technology, including a rechargeable battery, the current prototype is on the bulky side. However, the research team is constantly improving the design to make them smaller and lighter. A startup company, Sharpeyes, has been created to move toward commercialization with the aim of making the glasses available on the market in about three years.

This work was supported by the National Institute of Biomedical Imaging and Bioengineering through grant # U01EB023048.

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So you think you can secure your mobile phone with a fingerprint?

Similarities in partial fingerprints may be sufficient to trick biometric security systems on smartphones.

No two people are believed to have identical fingerprints, but researchers have found that partial similarities between prints are common enough that the fingerprint-based security systems used in electronic devices can be more vulnerable than previously thought. The vulnerability lies in the fact that fingerprint-based authentication systems feature small sensors that store partial fingerprints. The researchers found there could be enough similarities among different people's partial prints that one could create a 'MasterPrint.'

The vulnerability lies in the fact that fingerprint-based authentication systems feature small sensors that do not capture a user's full fingerprint. Instead, they scan and store partial fingerprints, and many phones allow users to enroll several different fingers in their authentication system. Identity is confirmed when a user's fingerprint matches any one of the saved partial prints. The researchers hypothesized that there could be enough similarities among different people's partial prints that one could create a "MasterPrint."

Nasir Memon, a professor of computer science and engineering at NYU Tandon and the research team leader, explained that the MasterPrint concept bears some similarity to a hacker who attempts to crack a PIN-based system using a commonly adopted password such as 1234. "About 4 percent of the time, the password 1234 will be correct, which is a relatively high probability when you're just guessing," said Memon. The research team set out to see if they could find a MasterPrint that could reveal a similar level of vulnerability. Indeed, they found that certain attributes in human fingerprint patterns were common enough to raise security concerns.

Memon and his colleagues, NYU Tandon Postdoctoral Fellow Aditi Roy and Michigan State University Professor of Computer Science and Engineering Arun Ross, undertook their analysis using 8,200 partial fingerprints. Using commercial fingerprint verification software, they found an average of 92 potential MasterPrints for every randomly sampled batch of 800 partial prints. (They defined a MasterPrint as one that matches at least 4 percent of the other prints in the randomly sampled batch.)

They found, however, just one full-fingerprint MasterPrint in a sample of 800 full prints. "Not surprisingly, there's a much greater chance of falsely matching a partial print than a full one, and most devices rely only on partials for identification," said Memon.

The team analyzed the attributes of MasterPrints culled from real fingerprint images, and then built an algorithm for creating synthetic partial MasterPrints. Experiments showed that synthetic partial prints have an even wider matching potential, making them more likely to fool biometric security systems than real partial fingerprints. With their digitally simulated MasterPrints, the team reported successfully matching between 26 and 65 percent of users, depending on how many partial fingerprint impressions were stored for each user and assuming a maximum number of five attempts per authentication. The more partial fingerprints a given smartphone stores for each user, the more vulnerable it is.

Roy emphasized that their work was done in a simulated environment. She noted, however, that improvements in creating synthetic prints and techniques for transferring digital MasterPrints to physical artifacts in order to spoof a device pose significant security concerns. The high matching capability of MasterPrints points to the challenges of designing trustworthy fingerprint-based authentication systems and reinforces the need for multi-factor authentication schemes. She said this work may inform future designs.

"As fingerprint sensors become smaller in size, it is imperative for the resolution of the sensors to be significantly improved in order for them to capture additional fingerprint features," Ross said. "If resolution is not improved, the distinctiveness of a user's fingerprint will be inevitably compromised. The empirical analysis conducted in this research clearly substantiates this."

Memon noted that the results of the team's research are based on minutiae-based matching, which any particular vendor may or may not use. Nevertheless, as long as partial fingerprints are used for unlocking devices and multiple partial impressions per finger are stored, the probability of finding MasterPrints increases significantly, he said.

"NSF's investments in cybersecurity research build the foundational knowledge base needed to protect us in cyberspace," said Nina Amla, program director in the Division of Computing and Communication Foundations at the National Science Foundation. "Much as other NSF-funded research has helped identify vulnerabilities in everyday technologies, such as cars or medical devices, investigating the vulnerabilities of fingerprint-based authentication systems informs continuous advancements in security, ensuring more reliable protection for users."

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Art of paper-cutting inspires self-charging paper device

Researchers have developed a paper-based device inspired by the Chinese and Japanese arts of paper-cutting that can harvest and store energy from body movements.

Credit: American Chemical Society

Despite the many advances in portable electronic devices, one thing remains constant: the need to plug them into a wall socket to recharge. Now researchers have developed a light-weight, paper-based device inspired by the Chinese and Japanese arts of paper-cutting that can harvest and store energy from body movements.

Portable electronic devices, such as watches, hearing aids and heart monitors, often require only a little energy. They usually get that power from conventional rechargeable batteries. But Zhong Lin Wang, Chenguo Hu and colleagues wanted to see if they could untether our small energy needs from the wall socket by harvesting energy from a user's body movements. Wang and others have been working on this approach in recent years, creating triboelectric nanogenerators (TENGs) that can harness the mechanical energy all around us, such as that created by our footsteps, and then use it to power portable electronics. But most TENG devices take several hours to charge small electronics, such as a sensor, and they're made of acrylic, which is heavy.

So the researchers turned to an ultra-light, rhombic paper-cut design a few inches long and covered it with different materials to turn it into a power unit. The four outer sides, made of gold- and graphite-coated sand paper, comprised the device's energy-storing supercapacitor element. The inner surfaces, made of paper and coated in gold and a fluorinated ethylene propylene film, comprised the TENG energy harvester. Pressing and releasing it over just a few minutes charged the device to 1 volt, which was enough to power a remote control, temperature sensor or a watch.

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Children notice what adults miss, study finds

While adults focus their attention, children see everything.

Although adults can beat children at most cognitive tasks, new research shows that children's limitations can sometimes be their strength. In two studies, researchers found that adults were very good at remembering information they were told to focus on, and ignoring the rest. In contrast, 4- to 5-year-olds tended to pay attention to all the information that was presented to them - even when they were told to focus on one particular item.

In two studies, researchers found that adults were very good at remembering information they were told to focus on, and ignoring the rest. In contrast, 4- to 5-year-olds tended to pay attention to all the information that was presented to them -- even when they were told to focus on one particular item. That helped children to notice things that adults didn't catch because of the grownups' selective attention.

"We often think of children as deficient in many skills when compared to adults. But sometimes what seems like a deficiency can actually be an advantage," said Vladimir Sloutsky, co-author of the study and professor of psychology at The Ohio State University.

"That's what we found in our study. Children are extremely curious and they tend to explore everything, which means their attention is spread out, even when they're asked to focus. That can sometimes be helpful."

The results have important implications for understanding how education environments affect children's learning, he said.

Sloutsky conducted the study with Daniel Plebanek, a graduate student in psychology at Ohio State. Their results were just published in the journal Psychological Science.

The first study involved 35 adults and 34 children who were 4 to 5 years old.

The participants were shown a computer screen with two shapes, with one shape overlaying the other. One of the shapes was red, the other green. The participants were told to pay attention to a shape of a particular color (say, the red shape).

The shapes then disappeared briefly, and another screen with shapes appeared. The participants had to report whether the shapes in the new screen were the same as in the previous screen.

In some cases, the shapes were exactly the same. In other cases, the target shape (the one participants were told to pay attention to) was different. But there were also instances where the non-target shape changed, even though it was not the one participants were told to notice.

Adults performed slightly better than children at noticing when the target shape changed, noticing it 94 percent of the time compared to 86 percent of the time for children.

"But the children were much better than adults at noticing when the non-target shape changed," Sloutsky said. Children noticed that change 77 percent of the time, compared to 63 percent of the time for adults.

"What we found is that children were paying attention to the shapes that they weren't required to," he said. "Adults, on the other hand, tended to focus only on what they were told was needed."

A second experiment involved the same participants. In this case, participants were shown drawings of artificial creatures with several different features. They might have an "X" on their body, or an "O"; they might have a lightning bolt on the end of their tail or a fluffy ball.

Participants were asked to find one feature, such as the "X" on the body among the "Os." They weren't told anything about the other features. Thus, their attention was attracted to "X" and "O," but not to the other features. Both children and adults found the "X" well, with adults being somewhat more accurate than children.

But when those features appeared on creatures in later screens, there was a big difference in what participants remembered. For features they were asked to attend to (i.e., "X" and "O"), adults and children were identical in remembering these features. But children were substantially more accurate than adults (72 percent versus 59 percent) at remembering features that they were not asked to attend to, such as the creatures' tails.

"The point is that children don't focus their attention as well as adults, even if you ask them to," Sloutsky said. "They end up noticing and remembering more."

Sloutsky said that adults would do well at noticing and remembering the ignored information in the studies, if they were told to pay attention to everything. But their ability to focus attention has a cost -- they miss what they are not focused on.

The ability of adults to focus their attention -- and children's tendency to distribute their attention more widely -- both have positives and negatives.

"The ability to focus attention is what allows adults to sit in two-hour meetings and maintain long conversations, while ignoring distractions," Sloutsky said.

"But young children's use of distributed attention allows them to learn more in new and unfamiliar settings by taking in a lot of information."

The fact that children don't always do as well at focusing attention also shows the importance of designing the right learning environment in classrooms, Sloutsky said.

"Children can't handle a lot of distractions. They are always taking in information, even if it is not what you're trying to teach them. We need to make sure that we are aware of that and design our classrooms, textbooks and educational materials to help students succeed.

"Perhaps a boring classroom or a simple black and white worksheet means less distraction and more successful learning," Sloutsky added.

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NASA's MAVEN reveals Mars has metal in its atmosphere

Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results. The metal ions can reveal previously invisible activity in the mysterious electrically charged upper atmosphere (ionosphere) of Mars.

MAVEN has made the first direct detection of the permanent presence of metal ions in the ionosphere of a planet other than Earth," said Joseph Grebowsky of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Because metallic ions have long lifetimes and are transported far from their region of origin by neutral winds and electric fields, they can be used to infer motion in the ionosphere, similar to the way we use a lofted leaf to reveal which way the wind is blowing." Grebowsky is lead author of a paper on this research appearing April 10 in Geophysical Research Letters.

MAVEN (Mars Atmosphere and Volatile Evolution Mission) is exploring the Martian upper atmosphere to understand how the planet lost most of its air, transforming from a world that could have supported life billions of years ago into a cold desert planet today. Understanding ionospheric activity is shedding light on how the Martian atmosphere is being lost to space, according to the team.

The metal comes from a constant rain of tiny meteoroids onto the Red Planet. When a high-speed meteoroid hits the Martian atmosphere, it vaporizes. Metal atoms in the vapor trail get some of their electrons torn away by other charged atoms and molecules in the ionosphere, transforming the metal atoms into electrically charged ions.

MAVEN has detected iron, magnesium, and sodium ions in the upper atmosphere of Mars over the last two years using its Neutral Gas and Ion Mass Spectrometer instrument, giving the team confidence that the metal ions are a permanent feature. "We detected metal ions associated with the close passage of Comet Siding Spring in 2014, but that was a unique event and it didn't tell us about the long-term presence of the ions," said Grebowsky.

The interplanetary dust that causes the meteor showers is common throughout our solar system, so it's likely that all solar system planets and moons with substantial atmospheres have metal ions, according to the team.

Sounding rockets, radar and satellite measurements have detected metal ion layers high in the atmosphere above Earth. There's also been indirect evidence for metal ions above other planets in our solar system. When spacecraft are exploring these worlds from orbit, sometimes their radio signals pass through the planet's atmosphere on the way to Earth, and sometimes portions of the signal have been blocked. This has been interpreted as interference from electrons in the ionosphere, some of which are thought to be associated with metal ions. However, long-term direct detection of the metal ions by MAVEN is the first conclusive evidence that these ions exist on another planet and that they are a permanent feature there.

The team found that the metal ions behaved differently on Mars than on Earth. Earth is surrounded by a global magnetic field generated in its interior, and this magnetic field together with ionospheric winds forces the metal ions into layers. However, Mars has only local magnetic fields fossilized in certain regions of its crust, and the team only saw the layers near these areas. "Elsewhere, the metal ion distributions are totally unlike those observed at Earth," said Grebowsky.

The research has other applications as well. For example it is unclear if the metal ions can affect the formation or behavior of high-altitude clouds. Also, detailed understanding of the meteoritic ions in the totally different Earth and Mars environments will be useful for better predicting consequences of interplanetary dust impacts in other yet-unexplored solar system atmospheres. "Observing metal ions on another planet gives us something to compare and contrast with Earth to understand the ionosphere and atmospheric chemistry better," said Grebowsky.

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Forget sponges: The earliest animals were marine jellies

One of the longest-running controversies in evolutionary biology has been, 'What was the oldest branch of the animal family tree?' Was it the sponges, as had long been thought, or was it the delicate marine predators called comb jellies? A powerful new method has been devised to settle contentious phylogenetic tree-of-life issues like this and it comes down squarely on the side of comb jellies.

When cartoonist and marine-biology teacher Steve Hillenburg created SpongeBob SquarePants in 1999, he may have backed the wrong side of one of the longest-running controversies in the field of evolutionary biology.

For the last decade, zoologists have been battling over the question, "What was the oldest branch of the animal family tree?" Was it the sponges, as they had long thought, or was it a distinctly different set of creatures, the delicate marine predators called comb jellies? The answer to this question could have a major impact on scientists' thinking about how the nervous system, digestive tract and other basic organs in modern animals evolved.

Now, a team of evolutionary biologists from Vanderbilt University and the University of Wisconsin-Madison have devised a new approach designed specifically to settle contentious phylogenetic tree-of-life issues like this. The new approach comes down squarely on the side of comb jellies.

The method and its application to this and 17 other controversial phylogenetic relationships was published online on Apr. 10 by the journal Nature Ecology & Evolution in an article titled "Resolution of contentious relationships in phylogenomic studies can be driven by one or a handful of genes."

For nearly a century, scientists organized the animal family tree based in large part on their judgement of the relative complexity of various organisms. Because of their comparative simplicity, sponges were considered to be the earliest members of the animal lineage. This paradigm began to shift when the revolution in genomics began providing vast quantities of information about the DNA of an increasing number of species. Evolutionary biologists started to apply this wealth of information to refine and redefine evolutionary relationships, creating a new field called phylogenomics. In most cases, the DNA data helped clarify these relationships. In a number of instances, however, it gave rise to controversies that intensified as more and more data accumulated.

In 2008, one of the early phylogenomic studies fingered the comb jellies (aka ctenophores) as the earliest members of the animal kingdom, rather than sponges. This triggered an ongoing controversy with the latest round being a massive study published last month that marshalled an unprecedented array of genetic data to support the sponges' position as the first animal offshoot.

"The current method that scientists use in phylogenomic studies is to collect large amounts of genetic data, analyze the data, build a set of relationships and then argue that their conclusions are correct because of various improvements they have made in their analysis," said Antonis Rokas, Cornelius Vanderbilt Professor of Biological Sciences, who devised the new approach with Vanderbilt postdoctoral scholar Xing-Xing Shen and Assistant Professor Chris Todd Hittinger from the University of Wisconsin-Madison. "This has worked extremely well in 95 percent of the cases, but it has led to apparently irreconcilable differences in the remaining 5 percent."

Rokas and his collaborators decided to focus on 18 of these controversial relationships (seven from animals, five from plants and six from fungi) in an attempt to figure out why the studies have produced such strongly contradictory results. To do so, they got down into the weeds, genetically speaking, and began comparing the individual genes of the leading contenders in each relationship.

"In these analyses, we only use genes that are shared across all organisms," Rokas said. "The trick is to examine the gene sequences from different organisms to figure out who they identify as their closest relatives. When you look at a particular gene in an organism, let's call it A, we ask if it is most closely related to its counterpart in organism B? Or to its counterpart in organism C? And by how much?"

These analyses typically involve hundreds to thousands of genes. The researchers determined how much support each gene provides to one hypothesis (comb-jellies first) over another (sponges first). They labeled the resulting difference a "phylogenetic signal." The correct hypothesis is the one that the phylogenetic signals from the most genes consistently favor.

In this fashion, they determined that comb jellies have considerably more genes which support their "first to diverge" status in the animal lineage than do sponges.

Another contentious relationship the researchers addressed was whether crocodiles are more closely related to birds or turtles. They found that 74 percent of the shared genes favor the hypothesis that crocodiles and turtles are sister lineages while birds are close cousins.

In the course of their study, they also discovered that in a number of contentious cases one or two "strongly opinionated genes" among all the genes being analyzed appear to be causing the problem because the statistical methods that evolutionary biologists have been using are highly susceptible to their influence.

In some cases, such as the controversies over the origins of flowering plants and modern birds, they determined that the removal of even a single opinionated gene can flip the results of an analysis from one candidate to another. In cases like this, the researchers were forced to conclude that the available data is either inadequate to support a definitive conclusion or it indicates that the diversification occurred too rapidly to resolve.

"We believe that our approach can help resolve many of these long-standing controversies and raise the game of phylogenetic reconstruction to a new level," Rokas said.

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Why is Rock so important?

As an example, geologists use rocks to determine how temperature changes affected Earth and life on Earth in the past. ... Granite and basalt may be the most important types of rocks in the Earth's crust. They are both igneous rocks, which means they form from cooling magma.

Rocks can answer a number of questions about what Earth was like in the past. They can indicate if a particular part of the Earth was under the ocean or on a mountaintop. Scientists also use them to help determine if the atmosphere was thick or thin and whether the climate was warm or cold at a given time.

Learning about how the Earth existed in the past allows scientists to learn how it works in the present and is likely to work in the future. As an example, geologists use rocks to determine how temperature changes affected Earth and life on Earth in the past. This helps scientists understand how global climate change is affecting the planet.

Granite and basalt may be the most important types of rocks in the Earth's crust. They are both igneous rocks, which means they form from cooling magma. Granite is the most common type of rock on continental landmasses, and basalt makes up most of the ocean floor.

Uses of Rock 

Rocks normally consist of several minerals, some essential, some accessory. A rock may be thought of as a "mineral environment." Each rock type was formed under certain specific conditions, resulting in the formation of a fairly predictable group of minerals. Rocks fall into three classes according to their origin: Igneous - Sedimentary - Metamorphic

COAL: A sedimentary rock, formed from decayed plants, is mainly used in power plants to make electricity.

LIMESTONE: A sedimentary rock, it is used mainly in the manufacture of Portland cement, the production of lime, manufacture of paper, petrochemicals, insecticides, linoleum, fiberglass, glass, carpet backing and as the coating on many types of chewing gum.

SHALE: A sedimentary rock, well stratified in thin beds. It splits unevenly more or less parallel to bedding plane and may contain fossils. It can be a component of bricks and cement.

CONGLOMERATE: A sedimentary rock with a variable hardness, consisted of rounded or angular rock or mineral fragments cemented by silica, lime, iron oxide, etc. Usually found in mostly thick, crudely stratified layers. Used in the construction industry.

SANDSTONE: A sedimentary rock more or less rounded. Generally thick-bedded, varicolored, rough feel due to uneven surface produced by breaking around the grains. Used principally for construction, it is easy to work, the red-brown sandstone of Triassic age, better known as "brownstone," has been used in many eastern cities.

GRANITE: An igneous-plutonic rock, medium to coarse-grained that is high in silica, potassium, sodium and quartz but low in calcium, iron and magnesium. It is widely used for architectural construction, ornamental stone and monuments.

PUMICE: An igneous-volcanic rock, it is a porous, brittle variety of rhyolite and is light enough to float. It is formed when magma of granite composition erupts at the earth’s surface or intrudes the crust at shallow depths. It is used as an abrasive material in hand soaps, emery boards, etc.

GABBRO: An igneous-plutonic rock, generally massive, but may exhibit a layered structure produced by successive layers of different mineral composition. It is widely used as crushed stone for concrete aggregate, road metal, railroad ballast, etc. Smaller quantities are cut and polished for dimension stone (called black granite).

BASALT: An igneous volcanic rock, dark gray to black, it is the volcanic equivalent of plutonic gabbro and is rich in ferromagnesian minerals. Basalt can be used in aggregate.

SCHIST: A metamorphic uneven-granular, medium to coarse grained, crystalline with prominent parallel mineral orientation. Goes from silvery white to all shades of gray with yellow to brown tones depending on the mineral concentration. Some schists have graphite and some are used as building stones.

GNEISS: A metamorphic uneven granular medium to coarse grained crystalline with more or less parallel mineral orientation. Colors are too variable to be of diagnostic value. Due to physical and chemical similarity between many gneisses and plutonic igneous rocks some are used as building stones and other structural purposes.

QUARTZITE: A metamorphic or sedimentary rock with crystalline texture, consists of rounded quartz grains cemented by crystalline quartz, generally white, light gray or yellow to brown. Same uses as sandstone.

MARBLE: A metamorphic even-granular grain to medium grained and may be uneven granular and coarse grained in calc-silicate rock. The normal color is white but accessory minerals act as coloring agents and may produce a variety of colors. Depending upon its purity, texture, color and marbled pattern it is quarried for use as dimension stone for statuary, architectural and ornamental purposes. Dolomite rich marble may be a source for magnesium and is used as an ingredient in the manufacture of refracting materials.

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