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20,000+ FREE Online Science and Technology Lectures from Top Universities

20,000+ FREE Online Science and Technology Lectures from Top Universities | Amazing Science |



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A surprising, cascading earthquake

A surprising, cascading earthquake | Amazing Science |

The 2016 Kaikoura earthquake (magnitude 7.8) on the South Island of New Zealand is among the most intriguing and best-documented seismic events anywhere in the world – and one of the most complex. The earthquake exhibited a number of unusual features, and the underlying geophysical processes have since been the subject of controversy.


LMU geophysicists Thomas Ulrich and Dr. Alice-Agnes Gabriel, in cooperation with researchers based at the Université Côte d'Azur in Valbonne and at Hong Kong Polytechnic University, have now simulated the course of the earthquake with an unprecedented degree of realism. Their model, which was run on the Bavarian Academy of Science’s supercomputer SuperMUC at the Leibniz Computing Center (LRZ) in Munich, elucidates dynamic reasons for such uncommon multi-segment earthquake.


This is an important step towards improving the accuracy of earthquake hazard assessments in other parts of the world. Their findings are being published in Nature Communications.

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Astronomers discover 83 supermassive black holes in the early universe

Astronomers discover 83 supermassive black holes in the early universe | Amazing Science |

Astronomers from Japan, Taiwan and Princeton University have discovered 83 quasars powered by supermassive black holes in the distant universe, from a time when the universe was only 5 percent of its present age.


"It is remarkable that such massive dense objects were able to form so soon after the Big Bang," said Michael Strauss, a professor of astrophysical sciences at Princeton University who is one of the co-authors of the study. "Understanding how black holes can form in the early universe, and just how common they are, is a challenge for our cosmological models."


This finding increases the number of black holes known at that epoch considerably, and reveals, for the first time, how common they are early in the universe's history. In addition, it provides new insight into the effect of black holes on the physical state of gas in the early universe in its first billion years. The research appears in a series of five papers published in The Astrophysical Journal and the Publications of the Astronomical Observatory of Japan.


Supermassive black holes, found at the centers of galaxies, can be millions or even billions of times more massive than the sun. While they are prevalent today, it is unclear when they first formed, and how many existed in the distant early universe. A supermassive black hole becomes visible when gas accretes onto it, causing it to shine as a "quasar." Previous studies have been sensitive only to the very rare, most luminous quasars, and thus the most massive black holes. The new discoveries probe the population of fainter quasars, powered by black holes with masses comparable to most black holes seen in the present-day universe.


The research team used data taken with a cutting-edge instrument, "Hyper Suprime-Cam" (HSC), mounted on the Subaru Telescope of the National Astronomical Observatory of Japan, which is located on the summit of Maunakea in Hawaii. HSC has a gigantic field-of-view -- 1.77 degrees across, or seven times the area of the full moon -- mounted on one of the largest telescopes in the world. The HSC team is surveying the sky over the course of 300 nights of telescope time, spread over five years.


The team selected distant quasar candidates from the sensitive HSC survey data. They then carried out an intensive observational campaign to obtain spectra of those candidates, using three telescopes: the Subaru Telescope; the Gran Telescopio Canarias on the island of La Palma in the Canaries, Spain; and the Gemini South Telescope in Chile. The survey has revealed 83 previously unknown very distant quasars. Together with 17 quasars already known in the survey region, the researchers found that there is roughly one supermassive black hole per cubic giga-light-year -- in other words, if you chunked the universe into imaginary cubes that are a billion light-years on a side, each would hold one supermassive black hole.


The sample of quasars in this study are about 13 billion light-years away from the Earth; in other words, we are seeing them as they existed 13 billion years ago. As the Big Bang took place 13.8 billion years ago, we are effectively looking back in time, seeing these quasars and supermassive black holes as they appeared only about 800 million years after the creation of the (known) universe.


It is widely accepted that the hydrogen in the universe was once neutral, but was "reionized" -- split into its component protons and electrons -- around the time when the first generation of stars, galaxies and supermassive black holes were born, in the first few hundred million years after the Big Bang. This is a milestone of cosmic history, but astronomers still don't know what provided the incredible amount of energy required to cause the reionization. A compelling hypothesis suggests that there were many more quasars in the early universe than detected previously, and it is their integrated radiation that reionized the universe.


"However, the number of quasars we observed shows that this is not the case," explained Robert Lupton, a 1985 Princeton Ph.D. alumnus who is a senior research scientist in astrophysical sciences. "The number of quasars seen is significantly less than needed to explain the reionization." Reionization was therefore caused by another energy source, most likely numerous galaxies that started to form in the young universe.

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Shocking: Nearly half of all pediatric cancers go undiagnosed and untreated worldwide, study finds

Shocking: Nearly half of all pediatric cancers go undiagnosed and untreated worldwide, study finds | Amazing Science |
Nearly one in two children with cancer are never diagnosed and may die untreated, according to a a new model proposed in a study published in The Lancet Oncology  by Zachary Ward and colleagues  from Harvard University T.H. Chan School of Public Health.

In fact, the model estimates that there were 397.000 childhood cancer cases globally in 2015, while only 224,000 had been previously recorded as diagnosed that year, leading ultimately the researchers to say that over 43% of childhood cancer cases were undiagnosed. But there was substantial regional variation: it ranges from 3% in both Western Europe (120 undiagnosed cases out of 4,300 total new cases) and North America (300 of 10,900 cases), to 57% (43,000 of 76,000 new cases) in Western Africa. With such path, at current levels of health system performances, If no improvements are made, the study authors estimated that nearly three million out of 6.7 million total cases will be missed between 2015 and 2030.

Accounting for underestimation is vital: accurate estimates of incidence are important for policy makers, however, many countries do not have cancer registries that quantify that incidence (and often even if they do have, cases might be incorrectly classified). “As the hidden incidence of childhood cancer starts to come to the fore, stronger health systems are needed for timely diagnosis, referral and treatment,” says Ward. “Expanding cancer registration will be important so that progress can be tracked.”

Although in most regions of the world the number of new childhood cancer cases is declining or stable, authors estimate that more than 90% of all new cases occur in low and middle-income countries. “Health systems in low-income and middle-income countries are clearly failing to meet the needs of children with cancer. Universal health coverage, a target of United Nations Sustainable Development Goals, must include cancer in children as a priority to prevent needless deaths,” says senior author Professor Rifat Atun, Harvard University, USA.
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Kicking neural network automation into high gear: ImageNet is 200 times faster than Google’s algorithm

Kicking neural network automation into high gear: ImageNet is 200 times faster than Google’s algorithm | Amazing Science |

MIT researchers have developed a neural architecture search (NAS) algorithm that designs optimized machine-learning models called convolutional neural networks on ImageNet 200 times faster than Google’s algorithm.


A new area in artificial intelligence involves using algorithms to automatically design machine-learning systems known as neural networks, which are more accurate and efficient than those developed by human engineers. But this so-called neural architecture search (NAS) technique is computationally expensive.

One of the state-of-the-art NAS algorithms recently developed by Google took 48,000 hours of work by a squad of graphical processing units (GPUs) to produce a single convolutional neural network, used for image classification and identification tasks. Google has the wherewithal to run hundreds of GPUs and other specialized circuits in parallel, but that's out of reach for many others.


In a new paper being presented at the International Conference on Learning Representations in May, MIT researchers describe an NAS algorithm that can directly learn specialized convolutional neural networks (CNNs) for target hardware platforms -- when run on a massive image dataset -- in only 200 GPU hours, which could enable far broader use of these types of algorithms. Resource-strapped researchers and companies could benefit from the time- and cost-saving algorithm, the researchers say. The broad goal is "to democratize AI," says co-author Song Han, an assistant professor of electrical engineering and computer science and a researcher in the Microsystems Technology Laboratories at MIT. "We want to enable both AI experts and non-experts to efficiently design neural network architectures with a push-button solution that runs fast on a specific hardware."


Han adds that such NAS algorithms will never replace human engineers. "The aim is to offload the repetitive and tedious work that comes with designing and refining neural network architectures," says Han, who is joined on the paper by two researchers in his group, Han Cai and Ligeng Zhu.


"Path-level" binarization and pruning

In their work, the researchers developed ways to delete unnecessary neural network design components, to cut computing times and use only a fraction of hardware memory to run a NAS algorithm. An additional innovation ensures each outputted CNN runs more efficiently on specific hardware platforms -- CPUs, GPUs, and mobile devices -- than those designed by traditional approaches. In tests, the researchers' CNNs were 1.8 times faster measured on a mobile phone than traditional gold-standard models with similar accuracy.

A CNN's architecture consists of layers of computation with adjustable parameters, called "filters," and the possible connections between those filters. Filters process image pixels in grids of squares -- such as 3x3, 5x5, or 7x7 -- with each filter covering one square. The filters essentially move across the image and combine all the colors of their covered grid of pixels into a single pixel. Different layers may have different-sized filters, and connect to share data in different ways. The output is a condensed image -- from the combined information from all the filters -- that can be more easily analyzed by a computer.

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Nanomachines in living systems - on route to microcyborgs

Nanomachines in living systems - on route to microcyborgs | Amazing Science |

From interaction with bacteria, propulsion based on cells, in vivo medical applications to even intracellular applications, the rapidly expanding development of micro- and nanomachines with sizes comparable to or even smaller than mammalian cells, has led this field to advance from understanding of basic motion mechanisms to applications in living biosystems.


The field of nanomachines has developed rapidly over the last few years, with several groups exploring new methods of navigation and demonstrating their potential benefits as therapeutic tools. In the future, these nanomachines could be used in a clinical environment, where they are injected close to a specific diseased site and they are navigated to a deep location of a tissue in a completely untethered and safe manner. The nanomachines can then perform tasks like sensing or therapy at the particular site, without affecting the functionality of adjoining cells and tissues.


Basic issues are switching their movement on and off all the way and the design of nanotransportation systems. Researchers recently designed a graphene nanomotor that mimics an internal combustion engine. Nature has excelled in designing molecular motors, which has led researchers to mimic bacterial flagella-based propulsion for nanomotors and use live bacteria as mechanical actuators in fluid systems


Increasingly, miniaturized artificial machines are designed for in vivo medical applications, for instance by coupling drug nanocarriers with self-propelled nanoshuttles in order to deliver therapeutic nanoparticles right to the spot where they are needed (e.g. a tumor site). Ultimately, we will see synthetic DNA nanomachines that go to work inside living cells to work as sensors or therapeutic agents. A recent review in Advanced Functional Materials ("Micro/Nanomachines and Living Biosystems: From Simple Interactions to Microcyborgs") highlights the recent efforts for and toward application of micro/nanomachines in living biosystems, including microorganisms, biological cells, and human body. 


The authors, professors Hong Wang (China University of Mining and Technology) and Martin Pumera (Nanyang Technological University), review the applications of micro/nanomachines in living biosystems from two aspects: their interaction with other microscopic organisms or biological units, and the efforts toward their application in the human body. They discuss four key application areas of micro- and nanomachines in living biosystems. Regarding the first aspect: interaction with bacteria and propulsion based on cells. Regarding the second aspect: in vivoapplications and intracellular applications.

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Augmented Reality Without Glasses Using Lightform Projection Mapping

Projection mapping is one of the most recent visual technologies that so far has been out of reach for consumers. The company Lightform is hoping to change that with its projector-mounted scanner and software. We get our hands on the Lightform device to see how it maps objects and environments in front of it--like a replica movie prop--and go through the software to learn how to create striking augmented visuals on top of the real world.


How it works

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Researchers discover new material to help power electronics

Researchers discover new material to help power electronics | Amazing Science |

Electronics rule our world, but electrons rule our electronics.

A research team at The Ohio State University has discovered a way to simplify how electronic devices use those electrons—using a material that can serve dual roles in electronics, where historically multiple materials have been necessary. The team published its findings today, March 18, in the journal Nature Materials.


“We have essentially found a dual-personality material,” said Joseph Heremans, co-author of the study, professor of mechanical and aerospace engineering and Ohio Eminent Scholar in Nanotechnology at Ohio State. “It is a concept that did not exist before.” Their findings could mean a revamp of the way engineers create all different kinds of electronic devices. This includes everything from solar cells, to the light-emitting diodes in your television, to the transistors in your laptop, and to the light sensors in your smartphone camera.


Those devices are the building blocks of electricity: Each electron has a negative charge and can radiate or absorb energy depending on how it is manipulated. Holes—essentially, the absence of an electron—have a positive charge. Electronic devices work by moving electrons and holes—essentially conducting electricity. But historically, each part of the electronic device could only act as electron-holder or a hole-holder, not both. That meant that electronics needed multiple layers—and multiple materials—to perform.


But the Ohio State researchers found a material—NaSn2As2, a crystal that can be both electron-holder and hole-holder—potentially eliminating the need for multiple layers. “It is this dogma in science, that you have electrons or you have holes, but you don’t have both. But our findings flip that upside down,” said Wolfgang Windl, a professor of materials science and engineering at Ohio State, and co-author of the study. “And it’s not that an electron becomes a hole, because it’s the same assembly of particles. Here, if you look at the material one way, it looks like an electron, but if you look another way, it looks like a hole.”


The finding could simplify our electronics, perhaps creating more efficient systems that operate more quickly and break down less often.

ThePlanetaryArchives - BlackHorseMedia - San Francisco's curator insight, March 20, 8:43 PM

"Depending on how you see a thing....."

-- Dee Lite

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Testing the symmetry of space-time by means of atomic clocks

Testing the symmetry of space-time by means of atomic clocks | Amazing Science |

The comparison of 2 atomic clocks has confirmed their excellent accuracy as well as a fundamental hypothesis of the theory of relativity.


According to Einstein the speed of light is always the same. But according to theoretical models of quantum gravitation, this uniformity of space-time does not apply to particles. Physicists have now tried to detect a change in the uniformity of space-time using two optical Ytterbium clocks. Their results are published in the current issue of Nature.


In his Special Theory of Relativity, Einstein formulated the hypothesis according to which the speed of light is always the same, no matter what the conditions are. It may, however, be possible that -- according to theoretical models of quantum gravitation -- this uniformity of space-time does not apply to particles. Physicists have now tested this hypothesis with a first long-term comparison of two optical ytterbium clocks at the Physikalisch-Technische Bundesanstalt (PTB).


With these clocks, whose error amounts to only one second in ten billion years, it should be possible to measure even extremely small deviations of the movement of the electrons in ytterbium. But the scientists did not detect any change when the clocks were oriented differently in space. Due to this result, the current limit for testing the space-time symmetry by means of experiments has been drastically improved by a factor of 100. In addition to this, the extremely small systematic measurement uncertainty of the optical ytterbium clocks of less than 4 × 10E-18 has been confirmed. The team consisting of physicists from PTB and from the University of Delaware has published its results in the current issue of Nature.


It is one of the most famous physics experiments in history: As early as 1887, Michelson and Morley demonstrated what Einstein later expressed in the form of a theory. With the aid of a rotating interferometer, they compared the speed of light along two optical axes running vertically to each other. The result of this experiment became one of the fundamental statements of Einstein's Special Theory of Relativity: The speed of light is the same in all directions of space. Now one could ask: Does this symmetry of space (which was named after Hendrik Antoon Lorentz) also apply to the motion of material particles? Or are there any directions along which these particles move faster or more slowly although the energy remains the same? Especially for high energies of the particles, theoretical models of quantum gravitation predict a violation of the Lorentz symmetry.


Now an experiment has been carried out with two atomic clocks in order to investigate this question with high accuracy. The frequencies of these atomic clocks are each controlled by the resonance frequency of a single Yb+ ion that is stored in a trap. While the electrons of the Yb+ ions have a spherically symmetric distribution in the ground state, in the excited state they exhibit a distinctly elongated wave function and therefore move mainly along one spatial direction. The orientation of the wave function is determined by a magnetic field applied inside the clock. The field orientation was chosen to be approximately at right angles in the two clocks.


The clocks are firmly mounted in a laboratory and rotate together with the Earth once a day (more exactly: once in 23.9345 hours) relative to the fixed stars. If the electrons' speed depended on the orientation in space, this would thus result in a frequency difference between the two atomic clocks that would occur periodically, together with the Earth's rotation. To be able to differentiate such an effect clearly from any possible technical influences, the frequencies of the Yb+ clocks were compared for more than 1000 hours. During the experiment, no change between the two clocks was observed for the accessible range of period durations from a few minutes up to 80 hours. For the theoretical interpretation and calculations concerning the atomic structure of the Yb+ ion, PTB's team worked in collaboration with theoreticians from the University of Delaware (USA). The results that have now been obtained have improved the limits set in 2015 by researchers from the University of California, Berkeley with Ca+ ions drastically by a factor of 100.


Averaged over the total measuring time, both clocks exhibited a relative frequency deviation of less than 3 × 10E-18. This confirms the combined uncertainty of the clock that had previously been estimated to be 4 × 10E-18. Furthermore, it is an important step in the characterization of optical atomic clocks at this level of accuracy. Only after roughly ten billion years would these clocks potentially deviate from each other by one second.

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A random anti-laser invented

A random anti-laser invented | Amazing Science |
The concept of the laser can be time-reversed: the perfect light source then becomes the perfect light absorber. Scientists at TU Wien have found a way to build such an anti-laser, based on random scattering.


Experimental setup of the random anti-laser: a waveguide contains a disordered medium consisting of a set of randomly placed Teflon cylinders, at which incoming microwave signals are scattered in a complex manner. In the top plate of the waveguide (moved aside for illustrative purposes) a central antenna is installed, which absorbs the microwaves.


In order to achieve perfect absorption, both the frequency of the incoming signal and the absorption strength of the central antenna have to be accurately tuned. Moreover, the wavefront of the microwave signal fed into the system through the external antennas (see blue cables) needs to be controlled precisely.


The laser is the perfect light source: when being provided with energy, it generates light of a specific, well-defined color. It is also possible, however, to create the exact opposite – an object that perfectly absorbs light of a particular color and dissipates the energy almost completely.

At TU Wien (Vienna), a method has now been developed to make use of this effect, even in very complicated systems in which light waves are randomly scattered in all directions. The method was developed by the team in Vienna with the help of computer simulations, and confirmed by experiments in cooperation with the University of Nice. This opens up new possibilities for all areas in science and engineering where wave phenomena play an important role. The new method has now been published in the journal "Nature".


"Waves that are being scattered in a complex way are really all around us - think about a mobile phone signal that is reflected several times before it reaches your cell phone," says Prof. Stefan Rotter from the Institute for Theoretical Physics of TU Wien. "This multiple scattering is made practical use of in so-called random lasers. Such exotic lasers are based on a disordered medium with a random internal structure that can trap light and emit a very complicated, system-specific laser field when supplied with energy."

With mathematical calculations and computer simulations, Rotter's team could show that this process can also be reversed in time. Instead of a light source that emits a specific wave depending on its random inner structure, it is also possible to build the perfect absorber, which completely dissipates an incoming wave with the right colour and spatial pattern in accordance with its characteristic internal structure. The easiest way to think about this process is in terms of a movie showing a conventional laser sending out laser light, which is played backwards.


"Because of this time-reversal analogy to a laser, such absorbers are called anti-lasers," says Stefan Rotter. "So far, anti-lasers have only been realized in one-dimensional structures onto which laser light was directed from opposite sides. Our approach is much more general: we were able to show that even arbitrarily complicated structures in two or three dimensions can perfectly absorb a suitably tailored wave. In this way, this novel concept can also be used for a much wider range of applications."

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Nanotechnology in healthcare

Nanotechnology in healthcare | Amazing Science |
Nanotechnology is becoming a crucial driving force behind innovation in medicine and healthcare, with a range of advances including nanoscale therapeutics, biosensors, implantable devices, drug delivery systems, and imaging technologies. This article provides a comprehensive overview of healthcare advances that may be possible through nanotechnology, ranging from fitness monitoring, prevention, diagnosis to therapy, and everything in between.


 In therapy, nanotechnology is at the forefront of both targeted drug delivery and intrinsic therapies. For instance, nanoparticles can be used as tumor-destroying hyperthermia agents that are injected into the tumor and then be activated to produce heat and destroy cancer cells locally either by magnetic fields, X-Rays or light. Sneaking existing chemotherapy drugs or genes into tumor cells via nanomaterials allows much more localized delivery both reducing significantly the quantity of drugs absorbed by the patient for equal impact and the side effects on healthy tissues in the body.


Coupling both modes of action has also been achieved with gold nanorods carrying chemotherapy drugs and locally excited in the tumor by infrared light. The induced heat both releases the encapsulated drug and helps destroying the cancer cells, resulting in a combined effect of enhanced delivery and intrinsic therapy.


Smart cancer theranostics – a combination of the words therapeutics and diagnostics – describes a treatment platform that combines a diagnostic test with targeted therapy based on the test results, i.e. a step towards personalized medicine.


In one recent study, targeted biodegradable nano 'drones' delivered a special type of drug that promotes healing successfully restructured atherosclerotic plaques in mice to make them more stable. This remodeling of the plaque environment would be predicted in humans to block plaque rupture and thrombosis and thereby prevent heart attacks and strokes.


In another study, researchers developed a new therapy to treat atherosclerosis and prevent heart failure with a new biomedical nanopolymer that reduces arterial plaque and inflammation in the cardiovascular system. Painful insulin injections could become a thing of the past for diabetes sufferers when smart insulin patches start replacing injections for diabetes.  Scientists even are working on a Type 1 diabetes vaccine by using liposomes that imitate cells in the process of natural death.


Nano- and microcarriers of drug substances can solve the problems with the drug delivery in the ocular tissues and nanoparticle drug delivery systems show great promise for related applications. There are even contact lens sensors for diabetic and glaucoma diagnosis under development that some day could include (for instance glaucoma) drug reservoirs that could be released by a smart system whenever needed.


Already, researchers have developed bioactive nanoengineered hydrogels for bone tissue engineering; designed 3D nanofiber scaffolding constructs for neural tissue engineering using stem cells; or demonstrated the fabrication of precise, biocompatible micro- and nanoscale architectures of silk proteins. And just recently, graphene foam has been demonstrated as a scaffold for growing functional muscle tissue.


The emergence of superbugs has made it imperative to search for novel methods, which can combat the microbial resistance. For this reason, the application of nanotechnology in pharmaceuticals and microbiology is gaining importance to prevent the catastrophic consequences of antibiotic resistance.


Nanotechnology based approaches to combat superbugs are advantageous to improve various preventive measures such as coatings and filtration. Similarly, diagnosis using efficient nanosensors or probes can speed up the treatment process at an early stage of disease. Nano-based drug carriers for existing antibiotics enhance their bioavailability and make them more targets specific. Also the combination of nanoparticles along with antibiotics makes them more lethal for micro-organisms.


Going one step further, there are efforts to replace antibiotics altogether with rapidly adaptable nanotherapeutics. They argue that recent advances in nanomaterials, genome sequencing, nucleotide synthesis, and bioinformatics could converge in nanotherapeutics with tailored sequence, specificity, and function that can overcome earlier challenges with small molecule-based approaches.


Nanosurgery tools hold the promise of studying or manipulating and repairing individual cells without damaging the cell. For instance, nanosurgery could remove or replace certain sections of a damaged gene inside a chromosome; sever axons to study the growth of nerve cells; or destroying an individual cell without affecting the neighboring cells.


Nanosurgical methods have been developed to target the cell’s internal organelles, the cell membrane, and the structural protein filaments within the cell (known as the “cytoskeleton”). Among the nanomanipulation techniques which exist, the atomic force microscope (AFM) is capable of imaging and working with extremely small structures with very high precision.

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Towards green, flexible protein-based electronics

Towards green, flexible protein-based electronics | Amazing Science |
Ionic conductors are a class of materials with key roles in energy storage, solar energy conversion, sensors, and electronic devices. In their quest towards eco-friendly alternatives for the current type of ionic conductors, researchers have developed an alternative green option based on organic silk and inorganic green laponite for the display and wearables industry via flexible and eco-friendly ionics. This could ultimately enable a wide range of applications within the field of flexible and wearable electronics.


In their paper in Advanced Science ("A Protein-Based, Water-Insoluble, and Bendable Polymer with Ionic Conductivity: A Roadmap for Flexible and Green Electronics") they demonstrate how to transform a natural polymer into an ionic material with stable performance in both aqueous and chemically active environments.


"Materials scientists have long loved silk for its exceptional mechanical properties; it competes with steel in terms of the breaking strength, and spider webs are only stronger options when it comes to bending and stretching," Alireza Dolatshahi-Pirouz, an Assistant Professor in the Department of Micro- and Nanotechnology at Technical University of Denmark, tells Nanowerk. "However, silk by itself is not a stable electrical conductor and that's why we have designed our new material silk-laponite (SiPo) and shown that this property is achieved through the interaction of silk with laponite."


By embedding laponite (a nanoclay) into silk-based thin films, the researchers generated an ionic conductor that exhibits a host of highly desirable properties: good crystallinity; transparency; mechanical strength'; recyclability; optical transparency; electrical sensitivity; as well as chemical, thermal, and dimensional stability.


SiPo is readily recyclable and can be recycled again and again; it is sustainable and maintains its high electrical sensitivity even after 2,000 bending cycles. SiPo could, therefore, be used in a number of devices in which high sensitivity is needed.


Another promising aspect of this technology is its low-cost (US$0.62 per unit) and scalable manufacturing process. This could potentially make these sensors suitable for mass production without compromising the environment.


To demonstrate the practical applicability of their technology, the researchers developed a flexible touchscreen as well as a human motion sensor that readily conforms to the curvatures of the body can measure motions from any part of the human body without any discomfort to the user.


 "Currently, we are developing a glove equipped with these flexible motion sensors," notes Dolatshahi-Pirouz. "Supported by DTU's Proof of Concept funding, in 10 months we will be ready with the first prototype of our E-glove, which would help surgeons to perform better in operations, translate sign language or even help the golfers improve their technique."


Other application areas for wearable sensors could be to gather biological information from athletes during games; soldiers during missions; and musicians to improve their performances by helping them to gain the needed mastery of their subtle motions during strenuous activities.


"Protein-based electronics still require additional consideration to enable them to resist the many demanding phenomena in nature and within the human body," cautions Dolatshahi-Pirouz. "Most of them quickly disintegrate in liquids and in response to various chemical and thermal stimuli. We will need to overcome these challenges before we could see their wide-spread use in daily life."

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Mathematically Designed New Acoustic Metamaterial For Noise Cancellation

Mathematically Designed New Acoustic Metamaterial For Noise Cancellation | Amazing Science |

Boston University researchers, Xin Zhang, a professor at the College of Engineering, and Reza Ghaffarivardavagh, a Ph.D. student in the Department of Mechanical Engineering, released a paper in Physical Review B demonstrating it's possible to silence noise using an open, ringlike structure, created to mathematically perfect specifications, for cutting out sounds while maintaining airflow.


"Today's sound barriers are literally thick heavy walls," says Ghaffarivardavagh. Although noise-mitigating barricades, called sound baffles, can help drown out the whoosh of rush hour traffic or contain the symphony of music within concert hall walls, they are a clunky approach not well suited to situations where airflow is also critical. Imagine barricading a jet engine's exhaust vent -- the plane would never leave the ground. Instead, workers on the tarmac wear earplugs to protect their hearing from the deafening roar.


Ghaffarivardavagh and Zhang let mathematics -- a shared passion that has buoyed both of their engineering careers and made them well-suited research partners -- guide them toward a workable design for what the acoustic metamaterial would look like. They calculated the dimensions and specifications that the metamaterial would need to have in order to interfere with the transmitted sound waves, preventing sound -- but not air -- from being radiated through the open structure. The basic premise is that the metamaterial needs to be shaped in such a way that it sends incoming sounds back to where they came from, they say.


As a test case, they decided to create a structure that could silence sound from a loudspeaker. Based on their calculations, they modeled the physical dimensions that would most effectively silence noises. Bringing those models to life, they used 3D printing to materialize an open, noise-canceling structure made of plastic.

Trying it out in the lab, the researchers sealed the loudspeaker into one end of a PVC pipe. On the other end, the tailor-made acoustic metamaterial was fastened into the opening.


With the hit of the play button, the experimental loudspeaker set-up came oh-so-quietly to life in the lab. Standing in the room, based on your sense of hearing alone, you'd never know that the loudspeaker was blasting an irritatingly high-pitched note. If, however, you peered into the PVC pipe, you would see the loudspeaker's subwoofers thrumming away.


The metamaterial, ringing around the internal perimeter of the pipe's mouth, worked like a mute button incarnate until the moment when Ghaffarivardavagh reached down and pulled it free. The lab suddenly echoed with the screeching of the loudspeaker's tune.


"The moment we first placed and removed the silencer...was literally night and day," says Jacob Nikolajczyk, who in addition to being a study co author and former undergraduate researcher in Zhang's lab is a passionate vocal performer. "We had been seeing these sorts of results in our computer modeling for months -- but it is one thing to see modeled sound pressure levels on a computer, and another to hear its impact yourself."

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Metamaterial that can solve equations

Metamaterial that can solve equations | Amazing Science |
Engineering professor Nader Engheta and his team have demonstrated a metamaterial device that can function as an analog computer, validating an earlier theory.


For Nader Engheta of the School of Engineering and Applied Science, one of the loftier goals in this field has been to design metamaterials that can solve equations. This “photonic calculus” would work by encoding parameters into the properties of an incoming electromagnetic wave and sending it through a metamaterial device; once inside, the device’s unique structure would manipulate the wave in such a way that it would exit encoded with the solution to a pre-set integral equation for that arbitrary input. 


In a paper published in Science, Engheta and his team demonstrated such a device for the first time. 

Their proof-of-concept experiment was conducted with microwaves, as the long wavelengths allowed for an easier-to-construct macro-scale device. The principles behind their findings, however, can be scaled down to light waves, eventually fitting onto a microchip. 


Such metamaterial devices would function as analog computers that operate with light, rather than electricity. They could solve integral equations—ubiquitous problems in every branch of science and engineering—orders of magnitude faster than their digital counterparts, while using less power.


Engheta, the H. Nedwill Ramsey Professor in the Department of Electrical and Systems Engineering, conducted the study along with lab members Nasim Mohammadi Estakhri and Brian Edwards. This approach has its roots in analog computing. The first analog computers solved mathematical problems using physical elements, such as slide-rules and sets of gears, that were manipulated in precise ways to arrive at a solution. In the mid-20th century, electronic analog computers replaced the mechanical ones, with series of resistors, capacitors, inductors, and amplifiers replacing their predecessors’ clockworks.


Such computers were state-of-the-art, as they could solve large tables of information all at once, but were limited to the class of problems they were pre-designed to handle. The advent of reconfigurable, programmable digital computers, starting with ENIAC, constructed at Penn in 1945, made them obsolete.      

As the field of metamaterials developed, Engheta and his team devised a way of bringing the concepts behind analog computing into the 21stcentury. Publishing a theoretical outline for “photonic calculus” in Science in 2014, they showed how a carefully designed metamaterial could perform mathematical operations on the profile of a wave passing thought it, such as finding its first or second derivative.

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The true-meaning of wearable displays: Self-powered, washable and wearable

The true-meaning of wearable displays: Self-powered, washable and wearable | Amazing Science |

When we think about clothes, they are usually formed with textiles and have to be both wearable and washable for daily use; however, smart clothing has had a problem with its power sources and moisture permeability, which causes the devices to malfunction. This problem has now been overcome by a KAIST research team, who developed a textile-based wearable display module technology that is washable and does not require an external power source.


To ease out the problem of external power sources and enhance the practicability of wearable displays, Professor Kyung Cheol Choi from the School of Electrical Engineering and his team fabricated their wearing display modules on real textiles that integrated polymer solar cells (PSCs) with organic light emitting diodes (OLEDs).


PSCs have been one of the most promising candidates for a next-generation power source, especially for wearable and optoelectronic applications because they can provide stable power without an external power source, while OLEDs can be driven with milliwatts. However, the problem was that they are both very vulnerable to external moisture and oxygen. The encapsulation barrier is essential for their reliability.


The conventional encapsulation barrier is sufficient for normal environments; however, it loses its characteristics in aqueous environments, such as water. It limits the commercialization of wearing displays that must operate even on rainy days or after washing.


To tackle this issue, the team employed a washable encapsulation barrier that can protect the device without losing its characteristics after washing through atomic layer deposition (ALD) and spin coating. With this encapsulation technology, the team confirmed that textile-based wearing display modules including PSCs, OLEDs, and the proposed encapsulation barrier exhibited little change in characteristics even after 20 washings with 10-minute cycles. Moreover, the encapsulated device operated stably with a low curvature radius of 3mm and boasted high reliability.


Finally, it exhibited no deterioration in properties over 30 days even after being subjected to both bending stress and washing. Since it uses a less stressful textile, compared to conventional wearable electronic devices that use traditional plastic substrates, this technology can accelerate the commercialization of wearing electronic devices. Importantly, this wearable electronic device in daily life can save energy through a self-powered system.


Prof. Choi said, "I could say that this research realized a truly washable wearable electronic module in the sense that it uses daily wearable textiles instead of the plastic used in conventional wearable electronic devices. Saving energy with PSCs, it can be self-powered, using nature-friendly solar energy, and washed. I believe that it has paved the way for a 'true-meaning wearable display' that can be formed on textile, beyond the attachable form of wearable technology."

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For Alzheimer’s disease early detection is not the end but the beginning

For Alzheimer’s disease early detection is not the end but the beginning | Amazing Science |

In the past, traditional diagnostic methods include detailed clinical interview and administration of questionnaires to assess thinking processes. However, with medical advancements such as an amyloid Positron Emission Tomography (PET) tracer recently made available in Singapore, Associate Professor Nagaendran has been able to combine radiopharmaceuticals and technology to provide his patients with a clearer diagnosis, earlier.


Amyloid is a key bio-marker for Alzheimer’s disease. Accumulation of insoluble amyloid results in loss of brain cells in the areas of the brain that regulate memory, calculation and other thinking processes. Unfortunately, before the availability of amyloid PET scans in Singapore, amyloid levels could only be measured after death.


“The techniques now enable quantification of amyloid in a living person, so a more precise understanding of the exact changes in the brain of patients with cognitive symptoms can be obtained,” says Associate Professor Nagaendran.


The PET scan is done with a radiopharmaceutical tracer injected into a patient about to undergo the scanning process and the tracer binds to the beta-amyloid plaques in the brain, appearing brightly on the scan. When the results of the female patient’s scan showed up as positive, Associate Professor Nagaendran confirmed that she had pre-dementia due to Alzheimer’s disease. According to NNI, 50% of people with pre-dementia eventually develop dementia. The news was initially devastating, but the patient knew she needed to remain positive about her options.


These days, both Associate Professor Nagaendran and his patient are contributing to the quest to understand Alzheimer’s disease, with the hope of one day finding a cure. NNI is one of the few centres in the world where patients have undergone the necessary pre-requisite tests to be confirmed as pre-dementia cases, giving them access to anti-amyloid clinical trial options.


Associate Professor Nagaendran continues to champion a better understanding of Alzheimer’s and disease-modifying treatments and his patient is enrolled in a clinical trial with an anti-amyloid intervention at NNI. She is now taking anti-amyloid medication, which is supposed to slow down the decline in memory and general function by reducing further build-up of amyloid in the brain.

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Finally! A DNA Computer That Can Actually Be Reprogrammed

Finally! A DNA Computer That Can Actually Be Reprogrammed | Amazing Science |
DNA computers have to date only been able to run one algorithm, but a new design shows how these machines can be made more flexible—and useful.


DNA is suppose to rescue us from a computing rut. With advances using silicon petering out, DNA-based computershold the promise of massive parallel computing architectures that are impossible today. But there’s a problem: The molecular circuits built so farhave no flexibility at all. Today, using DNA to compute is “like having to build a new computer out of new hardware just to run a new piece of software,” says computer scientist David Doty. So Doty, a professor at the University of California, Davis, and his colleagues set out to see what it would take to implement a DNA computer that was in fact reprogrammable.


As detailed in a paper published recently in Nature, Doty and his colleagues from Caltech and Maynooth University demonstrated just that. They showed it’s possible to use a simple trigger to coax the same basic set of DNA molecules into implementing numerous different algorithms. Although this research is still exploratory, reprogrammable molecular algorithms could be used in the future to program DNA robots, which have already successfully delivered drugs to cancerous cells. “This is one of the landmark papers in the field,” says Thorsten-Lars Schmidt, an assistant professor for experimental biophysics at Kent State University who was not involved in the research. “There was algorithmic self-assembly before, but not to this degree of complexity.”


In electronic computers like the one you’re using to read this article, bits are the binary units of information that tell a computer what to do. They represent the discrete physical state of the underlying hardware, usually the presence or absence of an electrical current. These bits, or rather the electrical signals implementing them, are passed through circuits made up of logic gates, which perform an operation on one or more input bits and produce one bit as an output.


By combining these simple building blocks over and over, computers are able to run remarkably sophisticated programs. The idea behind DNA computing is to substitute chemical bonds for electrical signals and nucleic acids for silicon to create biomolecular software. According to Erik Winfree, a computer scientist at Caltech and a co-author of the paper, molecular algorithms leverage the natural information processing capacity baked into DNA, but rather than letting nature take the reins, he says, “computation controls the growth process.”

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Truly Ghostly: How Spooky Quantum Particles Fly Through Barriers Almost Instantly

Truly Ghostly: How Spooky Quantum Particles Fly Through Barriers Almost Instantly | Amazing Science |
Researchers recently resolved a long-standing question in quantum physics, about how long it takes a single atom to tunnel through a barrier.


At the subatomic level, particles can fly through seemingly impassable barriers like ghosts. For decades, physicists have wondered just how long this so-called quantum tunneling takes. Now, after a three-year investigation, an international team of theoretical physicists has an answer. They measured a tunneling electron from a hydrogen atom and found that its passage was practically instantaneous, according to a new study [see 18 Times Quantum Particles Blow Our Minds].


Particles can pass through solid objects not because they're very small (though they are), but because the rules of physics are different at the quantum level. Imagine a ball rolling down a valley toward a slope as tall as Mount Everest; without a boost from a jetpack, the ball would never have enough energy to clear the hill. But a subatomic particle doesn't need to go over the hill to get to the other side.


Particles are also waves, which extend infinitely in space. According to the so-called wave equation, this means that a particle may be found in any position on the wave. Now picture the wave hitting a barrier; it continues on through but loses energy, and its amplitude (the height of the peak) dips way down. But if the obstacle is thin enough, the wave's amplitude doesn't decay down to zero. As long as there's still some energy left in the flattened wave, there's some chance — albeit a small one — that a particle may fly through the hill and out the other side.


Conducting experiments that captured this elusive activity at the quantum level was "very challenging" to say the least, study co-author Robert Sang, an experimental quantum physicist and a professor at Griffith University in Australia, told Live Science in an email. "You need to combine very complicated laser systems, a reaction microscope and a hydrogen atomic beam system to work all at the same time," Sang said. Their setup established three important reference points: the start of their interaction with the atom; the time that a freed electron was expected to emerge from behind a barrier; and the time when it actually appeared, Sang said in a video.


The researchers then used an optical timekeeping device called an attoclock — ultrashort, polarized light pulses capable of measuring electrons' movements to the attosecond, or a billionth of a billionth of a second. Their attoclock bathed hydrogen atoms in light at a rate of 1,000 pulses per second, which ionized the atoms so that their electrons could escape through the barrier, the researchers reported. A reaction microscope on the other side of a barrier measured the electron's momentum when it emerged. The reaction microscope detects energy levels in a charged particle after it interacts with the light pulse from the attoclock, "and from that we can infer the time it took to go through the barrier," Sang told Live Science.


"The precision that we could measure this to was 1.8 attoseconds," Sang said. "We were able to conclude that the tunneling must be less than 1.8 attoseconds — nearly instantly", he added.

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Humans prefer genetically dissimilar partners based on their major histocompatibility complex (MHC) and the ability to detect it via smell

Humans prefer genetically dissimilar partners based on their major histocompatibility complex (MHC) and the ability to detect it via smell | Amazing Science |

A team of researchers at Université Paris Diderot has found evidence that suggests humans are able to detect via smell which partners are genetically preferable. In their paper published in Proceedings of the Royal Society B, the group describes their study of the major histocompatibility complex (MHC) in people, and the ability to detect it via smell.


Prior research has shown that animals, including humans, are more successful from a genetic perspective when they mate with a partner that is genetically dissimilar in key ways. One of those differences is the makeup of their MHC—a cluster of genes that plays an important role in immune function. When two people with dissimilar clusters mate, their offspring gain the benefits of both parents.


In recent years, medical researchers have suspected that people are able to "sense" the makeup of a potential mate's MHC, and that people tend to find those with dissimilarities more attractive. It was assumed that if this were the case, that the olfactory system was responsible. The researchers with this new effort note that several studies have been conducted that were designed to determine if such theories were correct, but the results have varied widely. To find out once and for all, they conducted a larger, more thorough study.


The work involved analyzing data from the Database of Genotypes and Phenotypes managed by NIH. The researchers report that they were able to use genome-wide data from over 800 couples living in Europe and the Middle East (Israel)—more specifically, they were able to see how similar their MHCs were. The researchers report that on average, the MHCs between couples in Europe were dissimilar—more so than could be accounted for by randomness. They also noted that such differences were the most pronounced in couples living in the Netherlands. But they also report that they found no such degree of dissimilarity for couples living in Israel.


The researchers suggest their findings provide strong evidence of a human ability to smell MHC in other humans and to prefer mates with dissimilarities. They suggest such a preference can be overridden by cultural practices, however, such as those found in Israel, where mate choice is limited due to social standing or family practices.

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Speeding up the development of fusion power to create unlimited energy on Earth

Speeding up the development of fusion power to create unlimited energy on Earth | Amazing Science |
A look at the pathway to a compact fusion facility equipped with high-temperature superconducting magnets.


Can tokamak fusion facilities, the most widely used devices for harvesting on Earth the fusion reactions that power the sun and stars, be developed more quickly to produce safe, clean, and virtually limitless energy for generating electricity? Physicist Jon Menard of the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) has examined that question in a detailed look at the concept of a compact tokamak equipped with high temperature superconducting (HTS) magnets. Such magnets can produce higher magnetic fields -- necessary to produce and sustain fusion reactions -- than would otherwise be possible in a compact facility.


Menard first presented the paper, now published in Philosophical Transactions of the Royal Society A, to a Royal Society workshop in London that explored accelerating the development of tokamak-produced fusion power with compact tokamaks. "This is the first paper that quantitatively documents how the new superconductors can interplay with the high pressure that compact tokamaks produce to influence how tokamaks are optimized in the future," Menard said. "What we tried to develop were some simple models that capture important aspects of an integrated design."


"Very significant" findings

The findings are "very significant," said Steve Cowley, director of PPPL. Cowley noted that "Jon's arguments in this and the previous paper have been very influential in the recent National Academies of Sciences report," which calls for a U.S. program to develop a compact fusion pilot plant to generate electricity at the lowest possible cost. "Jon has really outlined the technical aspects for much smaller tokamaks using high-temperature magnets," Cowley said.


Compact tokamaks, which can include spherical facilities such as the National Spherical Torus Experiment-Upgrade (NSTX-U) that is under repair at PPPL and the Mega Ampere Spherical Tokamak (MAST) in Britain, provide some advantageous features. The devices, shaped like cored apples rather than doughnut-like conventional tokamaks, can produce high-pressure plasmas that are essential for fusion reactions with relatively low and cost-effective magnetic fields.


Such reactions fuse light elements in the form of plasma -- the hot, charged state of matter composed of free electrons and atomic nuclei -- to release energy. Scientists seek to replicate this process and essentially create a star on Earth to generate abundant electricity for homes, farms, and industries around the world. Fusion could last millions of years with little risk and without generating greenhouse gases.


Extends previous examination

Menard's study extends his previous examination of a spherical design that could develop materials and components for a fusion reactor and serve as a pilot plant to produce electric power. The current paper provides a detailed analysis of the complex tradeoffs that future experiments will need to explore when it comes to integrating compact tokamaks with HTS magnets. "We realize that there's no single innovation that can be counted on to lead to some breakthrough for making devices more compact or economical," Menard said. "You have to look at an entire integrated system to know if you are getting benefits from higher magnetic fields."


The paper focuses key issues on the size of the hole, defined as the "aspect ratio," in the center of the tokamak that holds and shapes the plasma. In spherical tokamaks, this hole can be half the size of the hole in conventional tokamaks, corresponding to the cored apple-like shape of the compact design. While physicists believe that lower aspect ratios can improve plasma stability and plasma confinement, "we won't know on the confinement side until we run experiments on the NSXT-U and the MAST upgrades," Menard said.

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Drug which makes human blood 'lethal' to mosquitoes can reduce malaria spread, study shows

Drug which makes human blood 'lethal' to mosquitoes can reduce malaria spread, study shows | Amazing Science |

A drug which poisons mosquitoes when they feed on it could provide a powerful new avenue for tackling malaria.  Trials showed it reduced cases among children in rural Burkina Faso by 20 per cent. Treating adults and children with the drug ivermectin helped to control the spread of malaria without causing harmful side-effects, the research led by a team at the Colorado State University found. They concluded that the new approach in combination with drugs to tackle the infections could slow down the creature's ability to resist the disease. 


Currently, conventional insecticides and anti-malarials and hampering the eradication effort. “Ivermectin reduces new cases of malaria by making a person’s blood lethal to the mosquitoes who bite them, killing mosquitoes and therefore reducing the likelihood of infection of others,” said Dr Brian Foy, author of the study published in The Lancet. 


Malaria’s life cycle is split between humans and its host mosquitos, the parasite is passed into the blood with a bite where it matures and multiplies and then waits to be transmitted on to the next mosquito to reproduce. Ivermectin is already used to treat other parasites causing river blindness and scabies, but its effects on malaria transmission haven’t been studied in a large trial.

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The Best Topological Conductor Yet: Spiraling Crystal Is the Key

The Best Topological Conductor Yet: Spiraling Crystal Is the Key | Amazing Science |
A team of researchers has discovered the strongest topological conductor yet – in thin crystal samples with a spiral staircase structure.


The realization of so-called topological materials -- which exhibit exotic, defect-resistant properties and are expected to have applications in electronics, optics, quantum computing, and other fields -- has opened up a new realm in materials discovery. Several of the hotly studied topological materials to date are known as topological insulators. Their surfaces are expected to conduct electricity with very little resistance, somewhat akin to superconductors but without the need for incredibly chilly temperatures, while their interiors -- the so-called "bulk" of the material -- do not conduct current.


Now, a team of researchers working at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has discovered the strongest topological conductor yet, in the form of thin crystal samples that have a spiral-staircase structure. The team's study of crystals, dubbed topological chiral crystals, is reported in the March 20 edition of the journal Nature. The DNA-like spiraling structure, or helicoid, in the crystal sample that was the focus of the latest study exhibits a chirality or "handedness" -- as a person can be either left-handed or right-handed, and the left hand is a mirror image of the right hand. Chiral properties in some cases can be flipped, like a left-handed person becoming a right-handed person.


"In this new work we are essentially proving that this is a new state of quantum matter, which is also exhibiting nearly ideal topological surface properties that emerge as a consequence of the chirality of crystal structure," said M. Zahid Hasan, a topological materials pioneer who led the materials theory and experiments as a visiting faculty scientist in the Materials Sciences Division at Berkeley Lab. Hasan is also the Eugene Higgins Professor of Physics at Princeton University.


A property that defines topological conductivity -- which is related to the electrical conductivity of the material's surface -- was measured to be about 100 times larger than that observed in previously identified topological metals.

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Contact lenses with built-in biofuel cells as power supply

Contact lenses with built-in biofuel cells as power supply | Amazing Science |
Enzymatic biofuel cells (EBFCs) are bioelectronic devices that utilize enzymes as the electrocatalysts to catalyze the oxidation of fuel and/or the reduction of oxygen or peroxide for energy conversion to electricity. EBFCs have already been demonstrated as wearable epidermal tattoo biosensors and in new work, researchers report the fabrication flexible EBFCs with flexible nanoporous gold electrodes that were modified with lactate oxidase and bilirubin oxidase for use as a lactate/O2 biofuel cell.


EBFCs have been demonstrated as wearable epidermal tattoo biosensors to harvest energy from lactate present in human sweat during physical exercise (for more details see: Electroanalysis"Tattoo-Based Wearable Electrochemical Devices: A Review"). Already in 2012, researchers demonstrated a biofuel cell as a power source for electronic contact lenses.


In this new work (ACS Applied Materials & Interfaces"Nanoporous Gold-Based Biofuel Cells on Contact Lenses"), researchers report the fabrication of flexible nanoporous gold electrodes that were modified with lactate oxidase and bilirubin oxidase for use as a lactate/O2 biofuel cell.

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Skin 3D bioprinter could replace skin grafts for burns and wounds

Skin 3D bioprinter could replace skin grafts for burns and wounds | Amazing Science |

Scientists at the Wake Forest Institute for Regenerative Medicine have invented a mobile system for bio-printing skin to do on-site treatments of wounds. The technology mixes skin cells with a hydrogel for the printer’s ink and then applying the mixture to a wound providing a boost to natural healing.


In a Scientific Reports paper published on February 12th 2019 entitled “In Situ Bioprinting of Autologous Skin Cells Accelerates Wound Healing of Extensive Excisional Full-Thickness Wounds,” the authors at the Wake Forest School of Medicine describe how over 7 million patients in the United States experience chronic and episodic wounds leading to $25 billion in annual expenses. Chronic wounds include diabetic, venous, and pressure ulcers. Episodic wounds come from burns and other external non-disease sources. They note that “full thickness” skin injuries are a major source of morbidity and mortality. More than 500,000 Americans annually suffer from burns requiring in-hospital treatment including skin grafts, and for the U.S. military, between 10 and 30% of combat casualties are a result of burn injuries.


The earlier skin wounds get treated leads to greater survivability from burn-related injuries. Currently, skin grafts are the gold standard but getting healthy donor grafts is fraught with potential challenges both in availability and in terms of immune rejection risks. Synthetic materials represent a substitute for grafts but they are costly and cosmetically produce less than desirable results.


A number of other types of technologies have been attempted to heal wounds and accelerate healing. These include spraying or applying liquids with skin cell tissue on wound sites to seed the healing process. The bioprinter takes the above processes several steps further.


The bioprinter consists of a handheld 3D scanner and print head with 8 nozzles each driven by its own dispensing motor. Its full reach extends to 127 centimeters (more than 4 feet) which makes it flexible to cover the entire torso of a patient. At the same time, the bioprinter form factor is small enough to easily be transported to almost any site. You can maneuver through doorframes easily. And once in position, it can be locked in place on an operating table to deliver bioprinting with high accuracy. To ensure the skin constructed is an exact fit with a patient’s wound, the bioprinter uses a real-time 3D laser scanner.
In initial comparisons with cell spraying and liquid application therapies, the bioprinter results show more rapid wound closure, reduced skin contraction, and faster healing. Human clinical trials are planned in the near future.
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Levitating objects with light

Levitating objects with light | Amazing Science |

Researchers at Caltech have designed a way to levitate and propel objects using only light, by creating specific nanoscale patterning on the objects' surfaces.


Though still theoretical, the work is a step toward developing a spacecraft that could reach the nearest planet outside of our solar system in 20 years, powered and accelerated only by light.


A paper describing the research appears online in the March 18 issue of the journal Nature Photonics. The research was done in the laboratory of Harry Atwater, Howard Hughes Professor of Applied Physics and Materials Science in Caltech's Division of Engineering and Applied Science.


Decades ago, the development of so-called optical tweezers enabled scientists to move and manipulate tiny objects, like nanoparticles, using the radiative pressure from a sharply focused beam of laser light. This work formed the basis for the 2018 Nobel Prize in Physics. However, optical tweezers are only able to manipulate very small objects and only at very short distances.


Ognjen Ilic, postdoctoral scholar and the study's first author, gives an analogy: "One can levitate a ping pong ball using a steady stream of air from a hair dryer. But it wouldn't work if the ping pong ball were too big, or if it were too far away from the hair dryer, and so on."


With this new research, objects of many different shapes and sizes -- from micrometers to meters -- could be manipulated with a light beam. The key is to create specific nanoscale patterns on an object's surface. This patterning interacts with light in such a way that the object can right itself when perturbed, creating a restoring torque to keep it in the light beam. Thus, rather than requiring highly focused laser beams, the objects' patterning is designed to "encode" their own stability. The light source can also be millions of miles away.


"We have come up with a method that could levitate macroscopic objects," says Atwater, who is also the director of the Joint Center for Artificial Photosynthesis. "There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We're a long way from actually doing that, but we are in the process of testing out the principles."

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"Grey Goo" Robot: A new kind of robot composed of many simple particles with no centralized control or single point of failure

"Grey Goo" Robot: A new kind of robot composed of many simple particles with no centralized control or single point of failure | Amazing Science |

The concept of “gray goo,” a robot comprised of billions of nanoparticles, has fascinated science fiction fans for decades. But most researchers have dismissed it as just a wild theory. Current robots are usually self-contained entities made of interdependent subcomponents, each with a specific function. If one part fails, the robot stops working. In robotic swarms, each robot is an independently functioning machine.


In a new study published today in Nature, researchers at Columbia Engineering and MIT Computer Science & Artificial Intelligence Lab (CSAIL) demonstrate for the first time a way to make a robot composed of many loosely coupled components, or “particles.” Unlike swarm or modular robots, each component is simple and has no individual address or identity. In their system, which the researchers call a “particle robot,” each particle can perform only uniform volumetric oscillations (slightly expanding and contracting), but cannot move independently.


The team, led by Hod Lipson, professor of mechanical engineering at Columbia Engineering, and CSAIL Director Daniela Rus, discovered that when they grouped thousands of these particles together in a “sticky” cluster and made them oscillate in reaction to a light source, the entire particle robot slowly began to move forward, towards the light.


Particle robots are composed of loosely coupled components, or particles, that lack an individual identity or addressable position. They are capable of only a simple motion—expansion and contraction. However, when a group of particles is coordinated to move as a collective, interesting behavior is observed. Even in amorphous configurations, particle robots exploit statistical mechanics phenomena to produce locomotion. The particle motion can be phase-modulated by an environmental stimulus, such as a light source. Here, we show a particle robot in which each component measures its light intensity, broadcasts its value to the group, and receives the intensity values of its neighbors to determine its phase delay. This produces undulating motion, with net movement towards the light source.


“You can think of our new robot as the proverbial ‘Gray Goo,’” says Lipson. “Our robot has no single point of failure and no centralized control. It’s still fairly primitive, but now we know that this fundamental robot paradigm is actually possible. We think it may even explain how groups of cells can move together, even though individual cells cannot.”


Researchers have been building autonomous robots for more than a century, but these have been non-biological machines that cannot grow, heal, or recover from damage. The Columbia Engineering/MIT team has been focused on developing robust, scalable robots that can function even when individual components fail.


“We’ve been trying to fundamentally rethink our approach to robotics, to discover if there is a way to make robots differently,” says Lipson, who directs the Creative Machines lab. “Not just make a robot look like a biological creature but actually construct it like a biological system, to create something that is vast in complexity and abilities yet composed of fundamentally simple parts.”


Rus, who is at MIT, adds, “All creatures in nature are made of cells that combine in different ways to make organisms. In developing particle robots, the question we ask is, can we have robotic cells that can be composed in different ways to make different robots? The robot could have the best shape required by the task—a snake to crawl through a tunnel or a three-handed machine for a factory floor. We could even give these particle robots the ability to make themselves. Suppose, for example, that a robot needs a screw driver from the table—the screw driver is too far to reach. What if the robot could reshuffle its cells to grow an extra long arm? As its goals change, its body can change too.”

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