A new way to design and 3-D print custom orthotics and prosthetics could give amputees, stroke patients and individuals with cerebral palsy lighter, better-fitting assistive devices in a fraction of the time it takes to get them today.
Developed by the University of Michigan College of Engineering, the system is being implemented at the U-M Orthotics and Prosthetics Center.
The U-M engineers and clinicians who designed the new cyber manufacturing system say that shortening the fabrication time for custom orthotics could make the process easier on custom assistive device users, who today must wait days or weeks to receive essential orthotics and prosthetics. The digital design and manufacturing process can also improve the devices’ precision, fit and function and improve consistency from one provider to the next.
Prostheses are devices used to replace a lost limb, while orthoses are braces used to protect, align or improve function or stability to injured limbs. Currently, the U-M team is focusing on ankle foot orthosis, which are often prescribed to stroke patients to help them regain their ability to walk. More than two-thirds of the 700,000 stroke victims in the United States each year require long-term rehabilitation, and many of them can be helped with custom orthotics. The devices can also help children with cerebral palsy, myelomeningocele and other conditions gain stability and walk more easily.
“Eventually we envision that a patient could come in in the morning for an optical scan, and the clinician could design a high quality orthosis very quickly using the cloud-based software,” said Albert Shih, U-M professor of mechanical and biomedical engineering and the lead on the project. “By that afternoon, they could have a 3-D printed device that’s ready for final evaluation and use.”
The new technique begins with a three-dimensional optical scan of the patient. The orthotist then uploads the scan data to a cloud-based design center and uses specially developed software to design the assistive device. Next, the software creates a set of electronic instructions and transmits them back to the orthotist’s facility, where an onsite 3-D printer produces the actual device in a few hours.
Jeff Wensman, director of clinical and technical services at U-M’s Orthotics and Prosthetics Center, says the new process is a major departure from current methods, which begin with wrapping fiberglass tapes around the patient’s limb. The tapes harden into a mold, which is then filled with plaster to make a model of the limb. Next, heated plastic is formed around the mode. The device is then hand-finished by smoothing the edges and attaching mechanical components like straps. It’s a labor-intensive process that requires a large shop and a highly trained staff.
By contrast, the only onsite equipment required by the new process is an optical scanner, a computer and a 3-D printer. In the future, this could give even small clinics in remote areas the ability to provide custom orthotics and prosthetics.
The lighter weight of the 3-D printed devices stems from a technique called “sparse structure,” which can make orthotics that are partially hollow using a wavy internal structure that saves weight without sacrificing strength. Developed by U-M mechanical engineering doctoral student Robert Chisena, sparse structure was initially intended as a way to print orthotics more quickly, but researchers quickly realized that it could make them better as well.
“Traditional hand-made orthotics are solid plastic, and they need to be a certain thickness because they have to be wrapped around a physical model during the manufacturing process,” Wensman said. “3-D printing eliminates that limitation. We can design devices that are solid in some places and hollow in others and vary the thickness much more precisely. It gives us a whole new set of tools to work with.”
Because the 3-D manufacturing process uses computer-based models rather than hand fabrication, it’s also more consistent than current methods. Any clinic with a 3-D printer could produce exactly the same device time after time. In addition, computer models of previous orthotics can provide doctors with a valuable record of how a patient’s shape and condition progress over time.
Eventually, the researchers plan to make the system’s software and specifications freely available so that other health care providers can roll out similar systems on their own.
A computer interface that can decipher the thoughts of people who are unable to communicate could revolutionize the lives of those living with completely locked-in syndrome, according to a new paper publishing January 31st, 2017 in PLOS Biology.
Counter to expectations, the participants in the study reported being “happy”, despite their extreme condition. The research was conducted by a multinational team, led by Professor Niels Birbaumer, at the Wyss Center for Bio and Neuroengineering in Geneva, Switzerland.
Patients suffering from complete paralysis, but with preserved awareness, cognition, and eye movements and blinking are classified as having locked-in syndrome. If eye movements are also lost, the condition is referred to as completely locked-in syndrome.
In the trial, patients with completely locked-in syndrome were able to respond “yes” or “no” to spoken questions, by thinking the answers. A non-invasive brain-computer interface detected their responses by measuring changes in blood oxygen levels in the brain.
The results overturn previous theories that postulate that people with completely locked-in syndrome lack the goal-directed thinking necessary to use a brain-computer interface and are, therefore, incapable of communication.
Extensive investigations were carried out in four patients with ALS (amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease) –a progressive motor neuron disease that leads to complete destruction of the part of the nervous system responsible for movement.
The researchers asked personal questions with known answers and open questions that needed “yes” or “no” answers including: “Your husband’s name is Joachim?” and “Are you happy?”. They found the questions elicited correct responses in seventy percent of the trials.
Professor Birbaumer said: “The striking results overturn my own theory that people with completely locked-in syndrome are not capable of communication. We found that all four patients we tested were able to answer the personal questions we asked them, using their thoughts alone. If we can replicate this study in more patients, I believe we could restore useful communication in completely locked-in states for people with motor neuron diseases.”
The question “Are you happy?” resulted in a consistent “yes” response from the four people, repeated over weeks of questioning.
Professor Birbaumer added: “We were initially surprised at the positive responses when we questioned the four completely locked-in patients about their quality of life. All four had accepted artificial ventilation in order to sustain their life, when breathing became impossible; thus, in a sense, they had already chosen to live. What we observed was that as long as they received satisfactory care at home, they found their quality of life acceptable. It is for this reason, if we could make this technique widely clinically available, it could have a huge impact on the day-to-day life of people with completely locked-in syndrome”.
In one case, a family requested that the researchers asked one of the participants whether he would agree for his daughter to marry her boyfriend ‘Mario’. The answer was “no”, nine times out of ten.
Professor John Donoghue, Director of the Wyss Center, said: “Restoring communication for completely locked-in patients is a crucial first step in the challenge to regain movement. The Wyss Center plans to build on the results of this study to develop clinically useful technology that will be available to people with paralysis resulting from ALS, stroke, or spinal cord injury. The technology used in the study also has broader applications that we believe could be further developed to treat and monitor people with a wide range of neuro-disorders.”
The brain-computer interface in the study used near-infrared spectroscopy combined with electroencephalography (EEG) to measure blood oxygenation and electrical activity in the brain. While other brain-computer interfaces have previously enabled some paralyzed patients to communicate, near-infrared spectroscopy is, so far, the only successful approach to restore communication to patients suffering from completely locked-in syndrome.
The device could aid people lacking drinking water and those affected by natural disasters
You’ve seen Bear Grylls turn foul water into drinking water with little more than sunlight and plastic.
Now, academics have added a third element — carbon-dipped paper — that may turn this survival tactic into a highly efficient and inexpensive way to turn saltwater and contaminated water into potable water for personal use.
The idea, which could help address global drinking water shortages, especially in developing areas and regions affected by natural disasters, is described in a study published online today (Jan. 30, 2017) in the journal Global Challenges.
“Using extremely low-cost materials, we have been able to create a system that makes near maximum use of the solar energy during evaporation. At the same time, we are minimizing the amount of heat loss during this process,” says lead researcher Qiaoqiang Gan, PhD, associate professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences.
Additional members of the research team are from UB’s Department of Chemistry, Fudan University in China, the University of Wisconsin-Madison and the lab of Gan, who is a member of UB’s New York State Center of Excellence in Materials Informatics and UB’s RENEW Institute, an interdisciplinary institute dedicated to solving complex environmental problems.
Solar vapor generator
To conduct the research, the team built a small-scale solar still. The device, which they call a “solar vapor generator,” cleans or desalinates water by using the heat converted from sunlight. Here’s how it works: The sun evaporates the water. During this process, salt, bacteria or other unwanted elements are left behind as the liquid moves into a gaseous state. The water vapor then cools and returns to a liquid state, where it is collected in a separate container without the salt or contaminants.
“People lacking adequate drinking water have employed solar stills for years, however, these devices are inefficient,” says Haomin Song, PhD candidate at UB and one of the study’s leading co-authors. “For example, many devices lose valuable heat energy due to heating the bulk liquid during the evaporation process. Meanwhile, systems that require optical concentrators, such as mirrors and lenses, to concentrate the sunlight are costly.”
The UB-led research team addressed these issues by creating a solar still about the size of mini-refrigerator. It’s made of expanded polystyrene foam (a common plastic that acts as a thermal insulator and, if needed, a flotation device) and porous paper coated in carbon black. Like a napkin, the paper absorbs water, while the carbon black absorbs sunlight and transforms the solar energy into heat used during evaporation.
The solar still coverts water to vapor very efficiently. For example, only 12 percent of the available energy was lost during the evaporation process, a rate the research team believes is unprecedented. The accomplishment is made possible, in part, because the device converts only surface water, which evaporated at 44 degrees Celsius.
Efficient and inexpensive
Based upon test results, researchers believe the still is capable of producing 3 to 10 liters of water per day, which is an improvement over most commercial solar stills of similar size that produce 1 to 5 liters per day.
Materials for the new solar still cost roughly $1.60 per square meter — a number that could decline if the materials were purchased in bulk. (By contrast, systems that use optical concentrators can retail for more than $200 per square meter.) If commercialized, the device’s retail price could ultimately reduce a huge projected funding gap — $26 trillion worldwide between 2010 and 2030, according to the World Economic Forum — needed for water infrastructure upgrades.
“The solar still we are developing would be ideal for small communities, allowing people to generate their own drinking water much like they generate their own power via solar panels on their house roof,” says Zhejun Liu, a visiting scholar at UB, PhD candidate at Fudan University and one the study’s co-authors.
Millions of tweets analyzed to measure perceived trustworthiness
By scanning 66 million tweets linked to nearly 1,400 real-world events, Georgia Institute of Technology researchers have built a language model that identifies words and phrases that lead to strong or weak perceived levels of credibility on Twitter. Their findings suggest that the words of millions of people on social media have considerable information about an event’s credibility – even when an event is still ongoing.
“There have been many studies about social media credibility in recent years, but very little is known about what types of words or phrases create credibility perceptions during rapidly unfolding events,” said Tanushree Mitra, the Georgia Tech Ph.D. candidate who led the research.
The team looked at tweets surrounding events in 2014 and 2015, including the emergence of Ebola in West Africa, the Charlie Hebdo attack in Paris and the death of Eric Garner in New York City. They asked people to judge the posts on their credibility (from “certainly accurate” to “certainly inaccurate”). Then the team fed the words into a model that split them into 15 different linguistic categories. The classifications included positive and negative emotions, hedges and boosters, and anxiety.
The Georgia Tech computer then examined the words to judge if the tweets were credible or not. It matched the humans’ opinions about 68 percent of the time. That’s significantly higher than the random baseline of 25 percent.
“Tweets with booster words, such as ‘undeniable,’ and positive emotion terms, such as ‘eager’ and ‘terrific,’ were viewed as highly credible,” Mitra said. “Words indicating positive sentiment but mocking the impracticality of the event, such as ‘ha,’ ‘grins’ or ‘joking,’ were seen as less credible. So were hedge words, including ‘certain level’ and ‘suspects.’”
Higher numbers of retweets also correlated with lower credibility scores. Replies and retweets with longer message lengths were thought to be more credible.
“It could be that longer message lengths provide more information or reasoning, so they’re viewed as more trustworthy,” she said. “On the other hand, a higher number of retweets, which was scored lower on credibility, might represent an attempt to elicit collective reasoning during times of crisis or uncertainty.”
The system isn’t deployable yet, but the Georgia Tech team says it could eventually become an app that displays the perceived trustworthiness of an event as it unfolds on social media.
“When combined with other signals, such as event topics or structural information, our linguistic result could be an important building block of an automated system,” said Eric Gilbert, Mitra’s advisor and an assistant professor in Georgia Tech’s School of Interactive Computing. “Twitter is part of the problem with spreading untruthful news online. But it can also be part of the solution.”
The paper, “A Parsimonious Language Model of Social Media Credibility Across Disparate Events,” will be presented in February at the 20th ACM Conference on Computer-Supported Cooperative Work and Social Computing in Portland, Oregon.
Learn more: Finding Credibility Clues on Twitter
In the latest edition of the professional journal “Science”, Jürgen Knoblich, a leading authority on stem cells and deputy director of the IMBA (Institute for Molecular Biotechnology of the Austrian Academy of Sciences), together with international experts, presents a first ethical guideline for research into human organ models. In the article, he also argues for critical and responsible engagement with the new technology.
Organ models, which are cultivated in the laboratory from human stem cells and grow into living tissue, are one of the most important scientific breakthroughs of recent years. Scientists, patients and the wider public have high hopes for this emerging field of research, as so-called “organoids” have a huge potential in terms of research and modern medicine. In-vitro organ models allow complex organ development studies and pathogenetic analyses to be carried out directly in human tissue. New substances and therapies can be tested on human material much more quickly using this technology. Regenerative medical practice could conceivably cultivate the required tissue in the laboratory from the cells of a patient and, lessen dependency on organ donations. The use of organoids could also significantly reduce the need for animal experiments, although biologists believe these cannot be completely eliminated in the foreseeable future.
Organoids – high hopes and bioethical dilemmas
From an ethical perspective, this new technology raises a whole range of issues. These include important caveats in relation to the use of human embryonic stem cells or the application of gene therapies to prevent or treat diseases. Jürgen Knoblich believes that “the development of organoids is unexplored scientific territory. As a researcher, I am fascinated by the huge potential of this technology. However, I also believe it’s my job to actively promote dialogue around responsible research and to engage the wider public in the discussion”. In 2013, the stem cell specialist made scientific headlines worldwide with his laboratory-cultivated brain models. In the latest policy statement issued in collaboration with the immunologist and geneticist Hans Clevers and the bioethicist and Member of the Dutch Parliament, Annelien Bredenoord, the researchers also examined for the first time the most important ethical dimensions of organoid research. According to Knoblich, “we hope that our work has created a solid foundation for the establishment of framework conditions for responsible engagement with this new technology”.
After demonstrating the first acoustically driven tractor beam platform, researchers develop a simpler, cheaper version using 3-D printable parts and open-source electronic components for the maker community
Last year Asier Marzo, then a doctoral student at the Public University of Navarre, helped develop the first single-sided acoustic tractor beam — that is, the first realization of trapping and pulling an object using sound waves from only one direction. Now a research assistant at the University of Bristol, Marzo has lead a team that adapted the technology to be, for all intents and purposes, 3-D printable by anyone (with some assembly required, of course).
In addition to a fully detailed how-to video that the group produced for the public, the results of the work developing this do-it-yourself, handheld acoustic tractor beam will appear this week as an open access paper in Applied Physics Letters, from AIP Publishing.
Sonic levitation is not new, and the use of sound waves to push around macroscopic objects, or create patterns in resting sand and flowing water, is scattered throughout YouTube and has been for years. This technology, however, is not simply sonic levitation, using sound to push objects around.
Based on similar fundamental physics used for decades to create optical traps, these tractor beams are true to their name in that they pull objects, trapping small beads — and even insects — at their foci.
“The most important thing is that it can attract the particle towards the source,” said Marzo. “It’s very easy to push particles from the source, but what’s hard is to pull them toward the source; to attract the particles. When you move the tractor beam, the particle moves, but otherwise the trap is static. It can levitate small plastics; it can also levitate a fly and small biological samples. It’s quite handy.”
The first versions of the device that proved the concept possible were not much larger than these new, 3-D printable versions. However, their underlying technology was more complex and required expensive electronics.
Much of the expense arose from the array of active components that electronically shaped sound waves, manipulating how and where they interfere to create the resulting object-trapping environment just above the array.
“Previously we developed a tractor beam, but it was very complicated and pricey because it required a phase array, which is a complex electronic system,” Marzo said. “In this paper, we made a simple, static tractor beam that only requires a static piece of matter.”
The simplicity (and affordability) of this passive, static-matter approach comes from the special architecture of that matter, designed to replace the phase array components and to shape sound waves structurally instead of electronically. As the sound, which now can be generated from a single source, passes through these carefully designed elements, the waves are shaped by the internal structure of the 3-D printed material.
“We can modulate a simple wave using what’s called a metamaterial which is basically a piece of matter with lots of tubes of different lengths. The sound passes through these tubes and when it exits the metamaterial, it has the correct phases to create a tractor beam,” said Marzo.
With an effect that is primarily determined by the shape of the tubes, the research team focused on optimizing the design to allow fabrication with common 3-D printers, ensuring it could be constructed even by at-home hobbyists.
According to Marzo, this was primarily a challenge in resolution, requiring a design that would not suffer from the limited precision of lower-end 3-D printer nozzles. “We needed to engineer the tubes very well to allow them to be 3-D printed with a normal 3-D printer. A normal 3-D printer has a lot of limitations,” he said.
With those limitations overcome, the group developed the rest of the tractor beam system using easily accessible components, such as from the popular open-source electronics supplier, Arduino. They even produced a detailed how-to video for its construction, a link to which is included below. “There will be a set of instructions with a list of the needed components and a step-by-step video. The components are very simple, like an Arduino and a motor driver, and everything can be bought on Amazon for less than £50 (about $70),” Marzo said.
Besides seriously impressing dinner guests, these DIY tractor beams have many potential uses and may even become a new tool for studying low-gravity effects on biological samples. Marzo pointed out this type of “micro-gravity” research is already of interest and encouraged biologists to find their own applications for the device.
“Recently there have been several papers about what happens if we levitate an embryo, how does it develop? Or what happens if we levitate bacteria?” he said. “For instance, they discovered salmonella is three times more [virulent] when it’s levitated. Certain microorganisms react differently to microgravity.”
There are three designs of the device, each with trapping profiles suitable for different object sizes relative to the wavelength of sound used. However, even for the full lab implementation where the group traps heavier objects and even liquids, trapping objects larger than half the wavelength of sound still poses a challenge. For practical frequencies, just above what humans can hear, this limits the size of trappable objects to a few millimeters.
As Marzo and his group work to overcome this challenge and continue to improve the capabilities of their tractor beams, the democratization of their technology paves the way for untold uses and tweaks from the maker community. So, the question really is — what would you do with your own tractor beam?
Learn more: How to 3-D Print Your Own Sonic Tractor Beam
Controls engineers at UC San Diego have developed practical strategies for building and coordinating scores of sensor-laden balloons within hurricanes.
Using onboard GPS and cellphone-grade sensors, each drifting balloon becomes part of a “swarm’’ of robotic vehicles, which can periodically report, via satellite uplink, their position, the local temperature, pressure, humidity and wind velocity.
This new, comparatively low-cost sensing strategy promises to provide much-needed in situ sampling of environmental conditions for a longer range of time and from many vantage points within developing hurricanes. This has the potential to greatly improve efforts to estimate and forecast the intensity and track of future hurricanes in real time.
Current two to five day forecasts of many hurricanes deviate significantly from each other, and from the truth. For example, as Hurricane Matthew churned toward the eastern seaboard in early October of 2016, various news outlets reported “forecasts” like “Hurricane Matthew will probably make landfall somewhere between Charleston and Boston, so everyone brace yourselves.”
“Guidance like this is entirely inadequate for evacuation and emergence response preparations,” said Thomas Bewley, a professor at the Jacobs School of Engineering at UC San Diego and the paper’s senior author.
Improved forecasts, to be greatly facilitated by improved in situ environmental sampling, are essential to protect property and save lives from such extreme environmental threats, he added.
Key challenges in this effort include the design of small, robust, buoyancy-controlled balloons that won’t accumulate ice; the efficient coordination of the motion of these balloons to keep them moving within the hurricane, between an altitude of 0 and 8 kilometers (about 5 miles); and to keep them well distributed over the dynamically significant regions within the hurricane, for up to a week at a time.
Bewley and UC San Diego post-doctoral researcher Gianluca Meneghello detail various aspects of their work on this problem in the October 2016 issue of the Physical Review Fluids, building upon work they published in the proceedings of the eighth International Symposium on Stratified Flows (ISSF) in San Diego, (Sept. 1, 2016). They plan to expand on their work at the forthcoming IEEE Aerospace Conference in Big Sky, Mont. (March 6, 2017).
|Typical spread of the zero- to five-day forecasts of the track of Hurricane Matthew, as performed by the major hurricane forecasting centers on (left) Oct 3, (middle) Oct 6, and (right) Oct 7, 2016.|
Data from http://www.emc.ncep.noaa.gov/gc_wmb/vxt/HWRF/tcall.php?selectYear=2016&selectBasin=North+Atlantic&selectStorm=MATTHEW14L
How the model works
The model for large-scale coordination of balloon swarms within hurricanes, as discussed in the Physical Review Fluids article, uses a clever strategy to model predictive control by leveraging the cutting-edge Weather Research and Forecasting code developed by the National Center for Atmospheric Research, the National Oceanic and Atmospheric Administration and the Air Force Weather Agency (AFWA). Multiple simulations indicate the remarkable effectiveness of this approach, including a simulation based on the evolution of Hurricane Katrina as it moved across the Gulf of Mexico, as summarized in the video available at http://flowcontrol.ucsd.edu/katrina.mp4
`The key idea of our large-scale balloon coordination strategy,’’ said Bewley, “is to `go with the flow,’ commanding small vertical movements of the balloons and leveraging the strong vertical stratification of the horizontal winds within the hurricane to distribute the balloons in the desired fashion horizontally.”
Intermediate-scale and small-scale fluctuations in the violent turbulent flow of a hurricane, which are unresolved by forecasting codes like WRF, are quite substantial. The researchers’ strategy? “We simply ride out the smaller-scale fluctuations of the flow,” said Meneghello. “The smaller-scale flowfield fluctuations induce something of a random walk in the balloon motion. We model these fluctuations statistically, and respond with corrections only if a balloon deviates too far from its desired location in the formation.”
Background on the project
As summarized in their ISSF paper, the researchers’ strategy for applying such corrections, dubbed Three Level Control (and endearingly abbreviated TLC), applies a finite shift to the vertical location of the displaced balloon for a short period of time, again leveraging the strong vertical stratification of the horizontal winds to return the balloon to its nominal desired location.
A third essential ingredient of the project, summarized in the researchers’ IEEE paper, is the design of small (about 3 kg or 6.5 lbs.), robust, energetically-efficient, buoyancy-controlled balloons that can survive, without significant accumulation of ice, in the cold, wet, turbulent, electrically active environment of a hurricane. The balloons can operate effectively for up to a week at a time on a battery charge not much larger than that of a handful of iPhones. “Cellphone-grade technologies, for both environmental sensors as well as low-energy radios and microprocessors, coupled with new space-grade balloon technology developed by Thin Red Line Aerospace, are on the cusp of making this ambitious robotic sensing mission feasible,” said Bewley.
Control theory applied
In addition to robotics, Bewley’s team specializes in the field of control theory, which is the essential “hidden technology” in many engineering applications, such as cruise control and adaptive suspension systems in cars, stability augmentation systems in high-performance aircraft and adaptive noise cancellation in telecommunication. Control theory made it possible for SpaceX rockets to land on barges at sea.
Though the math and numerical methods involved are sophisticated, the fundamental principle is straightforward: sensors take measurements of the physical environment, then a computer uses these measurements in real time to coordinate appropriate responses by the system (in this case, the buoyancy of the balloons) to achieve the desired effect.
Bewley, Meneghello and colleagues are now working towards testing the balloons and algorithms designed in this study in the real world. With sensor balloon swarms and the special TLC coming out of their lab, fire and safety officials may soon have a crucial extra couple of days to move people out of harm’s way, and to prepare emergency responses, when the next Katrina or Sandy threatens.
AlbertaSat will bring home world-class data using smaller-than-ever instruments with the fluxgate magnetometer on the Ex-Alta 1 CubeSat.
Smaller, faster, cheaper—miniaturised space technology opens the door to future University-based space exploration.
Researchers with the University of Alberta’s AlbertaSat team present the miniature fluxgate magnetometer, destined to go where no such magnetometer has gone before atop the Ex-Alta 1 CubeSat set for launch in spring 2017.
Designed and built by faculty and students with the University of Alberta Faculty of Science and Faculty of Engineering, the modern, low-cost, and miniature instrument will facilitate cutting-edge space research conducted from its place on-board cube satellites.
Democratizing the space race
“Historically, space research has used one, or at most a handful, of large, expensive spacecraft to explore near-Earth space and our solar system,” explains David Miles, PhD candidate in the Department of Physics and principal investigator for the instrument. “While this has provided stunning insight into our planet and our solar system, it necessarily gives a limited and incomplete picture.”
Nanosatellite technology, such as the fluxgate magnetometer, ushers in the next generation of space research which in future can open the door to swarms of miniaturised spacecraft encircling the Earth.
“Imagine trying to understand and predict the path hurricanes with only a few weather stations dotted around the world” said Ian Mann, professor in the Department of Physics and the co-lead for Ex-Alta-1. “That’s the current challenge for accurate space weather forecasting in the vastness of space around the Earth. However, miniaturised technology would enable swarms of perhaps hundreds of spacecraft or more to pin-point the potentially destructive paths of space storms.”
Weathering the storm
The newest space science instrument from the University of Alberta is a novel fluxgate magnetometer which will fly into space atop AlbertaSat’s Ex-Alta 1 CubeSat early next year. The miniature, low-cost instrument will take world-class measurements of the near-Earth magnetic field which influences space weather, demonstrating the potential of nanosatellite technology to significantly reduce barriers to entry and democratize the space race.
“Once we have a flight-proven instrument, we have several international collaborators interested in flying our instrument for their own research,” says Miles. “Tens or even hundreds of spacecraft can provide a dynamic, three-dimensional, and high-resolution picture of the space we inhabit, thereby improving the understanding of such threating space weather storms.”
Researchers at the University of Alberta have opportunities for undergraduate and graduate students to participate in this new space race using hands-on space research involving modelling, data analysis, meteorites, high-altitude balloons, sub-orbital rockets, and CubeSat missions. Interested students should contact the University of Alberta’s Institute for Space Science, Exploration and Technology.
A West Virginia University mathematics researcher has developed an algorithm to mobilize unmanned aerial vehicles (UAVs) in team missions.
The new technology allows a team of UAVs to fly autonomously to complete complex coordinated missions.
“Someone on the ground sets an area to be scanned by the UAVs. Within the area, the person selects different priority points for information-gathering. The algorithm then sets what coordinates are surveyed by which UAVs, and determines a plan for them so that it also covers as much of the area as possible without depleting the battery life,” said Marjorie Darrah, whose project is funded by the Army Research Laboratory.
“The technology is not bypassing the ground station, not taking over the flight plan. It is just giving the ground station help to complete a complex mission with three planes at once.”
The new genetic algorithm is designed for the Raven, a UAV used by United States military and Special Operations Command as well as military operations in Austria, Estonia, Italy, Denmark, Spain and the Czech Republic.
More than 19,000 Ravens are in service, making them one of the most widely adopted UAV systems in the world. However, they can only be purchased in packages of three. Because they are generally flown individually, this research is an opportunity to use the technology more efficiently.
“(Ravens) are never really used in the capacity of what’s at their disposal,” Darrah said. “What we’ve developed can encourage the military to use a piece of add-on software that works along with the ground station.”
Military operations typically use UAVs for wide area searches and surveillance, enemy air defense and conducting intelligence, surveillance and reconnaissance, such as securing a military base or a specific area.
Civilian operations can also utilize UAVs in teams with the genetic algorithm. The team-approach is useful for monitoring biological threats to agriculture, detecting fires, conducting transportation surveillance and managing natural disasters.
Marcela Mera Trujillo, a mathematics graduate student in Darrah’s lab, is working to use a similar genetic algorithm approach to employ various mapping techniques in another civilian application. She is creating highly detailed, high resolution 3-D maps using multirotors that fly over structures and capture images from many different angles.
“This is an idea (Trujillo) is working on with 4-D Tech Solutions, a small business in Morgantown,” Darrah said. “It is a good model for the University to work with government labs and small business. Through a summer internship, Trujillo has helped develop a provisional patent for the 3-D mapping algorithm.”
Darrah’s research team was featured on the cover of the fall 2016 edition of DSIAC Journal, the Defense Systems Information Analysis Center’s quarterly magazine that introduces new technology to all branches of the military within the Department of Defense.
“15 years ago, this (technology) was an idea. Now it’s a reality,” Darrah said. “Now that we are seeing how the Raven is being used in many countries around the world—it’s versatile, hand-launched, robust—we can encourage people to use the technology in new ways.”
With Unmanned Aerial Vehicles (UAVs) or drones gaining popularity globally for commercial, recreational and industry purposes, hundreds of UAVs may soon be buzzing all over Singapore.
The lower cost of drones and rising demand for commercial drone services have already led to a boom in the number of drones taking to the skies in Singapore.
With Singapore’s limited airspace and dense population, the need for an aerial traffic management system to allow drones to fly safely has become more urgent.
Researchers at Nanyang Technological University, Singapore (NTU Singapore) are studying ways to allow hundreds of UAVs to fly efficiently and safely at any one time.
The aim is to develop a traffic management system for UAVs consisting designated air-lanes and blocks, similar to how cars on the roads have traffic lights and lanes.
Advanced technologies that will be developed include smart and safe routing, detect- and-avoid systems, and traffic management to coordinate air traffic.
Named Traffic Management of Unmanned Aircraft Systems, this initiative is spearheaded by NTU’s Air Traffic Management Research Institute (ATMRI).
ATMRI is a joint research centre by NTU and the Civil Aviation Authority of Singapore (CAAS). It aims to research and develop air traffic management solutions for Singapore and the Asia Pacific region, including UAV traffic management which is one of its key programmes.
Leading the research programme are NTU Professor Low Kin Huat, an expert in robotics and UAVs from the School of Mechanical and Aerospace Engineering, and ATMRI Senior Research Fellow, Mr Mohamed Faisal Bin Mohamed Salleh.
Prof Low said it is important to develop a traffic management solution for UAVs tailored to actual challenges faced by Singapore given the huge growth of UAV traffic expected over the next decade.
“At NTU, we have already demonstrated viable technologies such as UAV convoys, formation flying and logistics, which will soon become mainstream,” explained Prof Low. “This new traffic management project will test some of the new concepts developed with the aim of achieving safe and efficient drone traffic in our urban airways.”
“The implications of the project will have far reaching consequences, as we are developing ways for seamless travel of unmanned aircrafts for different purposes without compromising safety, which is of paramount importance.”
Professor Louis Phee, Chair of NTU’s School of Mechanical and Aerospace Engineering, said the UAV research at NTU is a natural progression, with the school’s deep expertise in autonomous vehicles and robotics developed over the last decade.
“This research will pave the way for appropriate rules and regulations to be implemented amidst the rapid growth of UAVs. The findings can help improve safety and address security concerns, which are especially important given today’s climate of uncertainty.”
Coordinating centres to track airborne drones
To ensure that traffic is regulated across the whole of Singapore, a possible solution is the establishment of coordinating stations for UAV traffic. These stations can then track all the UAVs that are in the air, schedule the traffic flow, monitor their speeds and ensure a safe separation between the UAVs.
Mr Faisal, the co-investigator of the programme, said various scenarios will be tested out using computer simulations and software to optimise UAV traffic routes, so as to minimise traffic congestions.
“We will also look into proposing safety standards, for instance how high UAVs should fly and how far they should be flying above buildings, taking privacy concerns and laws into consideration, and to suggest recommended actions during contingencies,” said Mr Faisal, who is also Deputy Director at ATMRI.
One proposed strategy is to use the current infrastructure such as open fields for take-off and landing and having UAVs fly above buildings and HDB flats, which can act as emergency landing sites to minimise risk to the public.
Currently, restricted airspace and zones where UAV operations are prohibited have already been identified, such as near airports and military facilities.
The researchers will test out several concepts, such as geofencing. The idea is to set up virtual fences where UAVs can be automatically routed around a restricted geographical location such as the airport.
Another important research area will be collision detection. UAVs will need to have sensors that enable detection and avoidance of collision with another UAV. This will allow UAVs to follow a set of actions to avoid any mid-air incidents, such as flying above, below, or around other UAVs.
This multidisciplinary research initiative will bring together faculty and researchers from different fields in NTU, from aerospace engineering and air traffic management to robotics and electronic engineering.
Spanning a period of four years, the project which will also tap on industry experts, is expected to complete its initial phase of conceptual design and software simulation by end 2017.
This is followed by actual test bedding of solutions using UAVs developed by NTU that can be used for relevant applications in 2018.
Instead of ordering batteries by the pack, we might get them by the ream in the future.
Researchers at Binghamton University, State University of New York have created a bacteria-powered battery on a single sheet of paper that can power disposable electronics. The manufacturing technique reduces fabrication time and cost, and the design could revolutionize the use of bio-batteries as a power source in remote, dangerous and resource-limited areas.
“Papertronics have recently emerged as a simple and low-cost way to power disposable point-of-care diagnostic sensors,” said Assistant Professor Seokheun “Sean” Choi, who is in the Electrical and Computer Engineering Department within the Thomas J. Watson School of Engineering and Applied Science. He is also the director of the Bioelectronics and Microsystems Lab at Binghamton.
“Stand-alone and self-sustained, paper-based, point-of-care devices are essential to providing effective and life-saving treatments in resource-limited settings,” said Choi.
On one half of a piece of chromatography paper, Choi and PhD candidate Yang Gao, who is a co-author of the paper, placed a ribbon of silver nitrate underneath a thin layer of wax to create a cathode. The pair then made a reservoir out of a conductive polymer on the other half of the paper, which acted as the anode. Once properly folded and a few drops of bacteria-filled liquid are added, the microbes’ cellular respiration powers the battery.
“The device requires layers to include components, such as the anode, cathode and PEM (proton exchange membrane),” said Choi. “[The final battery] demands manual assembly, and there are potential issues such as misalignment of paper layers and vertical discontinuity between layers, which ultimately decrease power generation.”
Different folding and stacking methods can significantly improve power and current outputs. Scientists were able to generate 31.51 microwatts at 125.53 microamps with six batteries in three parallel series and 44.85 microwatts at 105.89 microamps in a 6×6 configuration.
It would take millions of paper batteries to power a common 40-watt light bulb, but on the battlefield or in a disaster situation, usability and portability is paramount. Plus, there is enough power to run biosensors that monitor glucose levels in diabetes patients, detect pathogens in a body or perform other life-saving functions.
“Among many flexible and integrative paper-based batteries with a large upside, paper-based microbial fuel cell technology is arguably the most underdeveloped,” said Choi. “We are excited about this because microorganisms can harvest electrical power from any type of biodegradable source, like wastewater, that is readily available. I believe this type of paper biobattery can be a future power source for papertronics.”
The innovation is the latest step in paper battery development by Choi. His team developed its first paper prototype in 2015, which was a foldable battery that looked much like a matchbook. Earlier this year they unveiled a design that was inspired by a ninja throwing star.
Researchers at Columbia University, Princeton and Harvard University have developed a new approach for analyzing big data that can drastically improve the ability to make accurate predictions about medicine, complex diseases, social science phenomena, and other issues.
In a study published in the December 13 issue of Proceedings of the National Academy of Sciences (PNAS), the authors introduce the Influence score, or “I-score,” as a statistic correlated with how much variables inherently can predict, or “predictivity”, which can consequently be used to identify highly predictive variables.
“In our last paper, we showed that significant variables may not necessarily be predictive, and that good predictors may not appear statistically significant,” said principal investigator Shaw-Hwa Lo, a professor of statistics at Columbia University. “This left us with an important question: how can we find highly predictive variables then, if not through a guideline of statistical significance? In this article, we provide a theoretical framework from which to design good measures of prediction in general. Importantly, we introduce a variable set’s predictivity as a new parameter of interest to estimate, and provide the I-score as a candidate statistic to estimate variable set predictivity.”
Current approaches to prediction generally include using a significance-based criterion for evaluating variables to use in models and evaluating variables and models simultaneously for prediction using cross-validation or independent test data.
“Using the I-score prediction framework allows us to define a novel measure of predictivity based on observed data, which in turn enables assessing variable sets for, preferably high, predictivity,” Lo said, adding that, while intuitively obvious, not enough attention has been paid to the consideration of predictivity as a parameter of interest to estimate. Motivated by the needs of current genome-wide association studies (GWAS), the study authors provide such a discussion.
In the paper, the authors describe the predictivity for a variable set and show that a simple sample estimation of predictivity directly does not provide usable information for the prediction-oriented researcher. They go on to demonstrate that the I-score can be used to compute a measure that asymptotically approaches predictivity. The I-score can effectively differentiate between noisy and predictive variables, Lo explained, making it helpful in variable selection. A further benefit is that while usual approaches require heavy use of cross-validation data or testing data to evaluate the predictors, the I-score approach does not rely as much on this as much.
“We offer simulations and an application of the I-score on real data to demonstrate the statistic’s predictive performance on sample data,” he said. “These show that the I-score can capture highly predictive variable sets, estimates a lower bound for the theoretical correct prediction rate, and correlates well with the out of sample correct rate. We suggest that using the I-score method can aid in finding variable sets with promising prediction rates, however, further research in the avenue of sample-based measures of predictivity is needed.”
The authors conclude that there are many applications for which using the I-score would be useful, for example in formulating predictions about diseases with high dimensional data, such as gene datasets, in the social sciences for text prediction or financial markets predictions; in terrorism, civil war, elections and financial markets.
“We’re hoping to impress upon the scientific community the notion that for those of us who might be interested in predicting an outcome of interest, possibly with rather complex or high dimensional data, we might gain by reconsidering the question as one of how to search for highly predictive variables (or variable sets) and using statistics that measure predictivity to help us identify those variables to then predict well,” Lo said. “For statisticians in particular, we’re hoping this opens up a new field of work that would focus on designing new statistics that measure predictivity.”