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    Human learning can be duplicated in solid matter

    Rutgers researchers and their collaborators have found that learning — a universal feature of intelligence in living beings — can be mimicked in synthetic matter, a discovery that in turn could inspire new algorithms for artificial intelligence (AI).
    The study appears in the journal PNAS.
    One of the fundamental characteristics of humans is the ability to continuously learn from and adapt to changing environments. But until recently, AI has been narrowly focused on emulating human logic. Now, researchers are looking to mimic human cognition in devices that can learn, remember and make decisions the way a human brain does.
    Emulating such features in the solid state could inspire new algorithms in AI and neuromorphic computing that would have the flexibility to address uncertainties, contradictions and other aspects of everyday life. Neuromorphic computing mimics the neural structure and operation of the human brain, in part, by building artificial nerve systems to transfer electrical signals that mimic brain signals.
    Researchers from Rutgers, Purdue and other institutions studied how the electrical conductivity of nickel oxide, a special type of insulating material, responded when its environment was changed repeatedly over various time intervals.
    “The goal was to find a material whose electrical conductivity can be tuned by modulating the concentration of atomic defects with external stimuli such as oxygen, ozone and light,” said Subhasish Mandal, a postdoctoral associate in the Department of Physics and Astronomy at Rutgers-New Brunswick. “We studied how this material behaves when we dope the system with oxygen or hydrogen, and most importantly, how the external stimulation changes the material’s electronic properties.”
    The researchers found that when the gas stimulus changed rapidly, the material couldn’t respond in full. It stayed in an unstable state in either environment and its response began to decrease. When the researchers introduced a noxious stimulus such as ozone, the material began to respond more strongly only to decrease again.
    “The most interesting part of our results is that it demonstrates universal learning characteristics such as habituation and sensitization that we generally find in living species,” Mandal said. “These material characteristics in turn can inspire new algorithms for artificial intelligence. Much as collective motion of birds or fish have inspired AI, we believe collective behavior of electrons in a quantum solid can do the same in the future.
    “The growing field of AI requires hardware that can host adaptive memory properties beyond what is used in today’s computers,” he added. “We find that nickel oxide insulators, which historically have been restricted to academic pursuits, might be interesting candidates to be tested in future for brain-inspired computers and robotics.”
    The study included Distinguished Professor Karin Rabe from Rutgers and researchers from Purdue University, the University of Georgia and Argonne National Laboratory.
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    Materials provided by Rutgers University. Original written by John Cramer. Note: Content may be edited for style and length. More

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    Tube-shaped robots roll up stairs, carry carts, and race one another

    Researchers have designed a 4D-printed soft robot that self-assembles when heated and can take on challenging tasks like rolling uphill and navigating a bumpy and unpredictable landscape. The prototype, which is tube-shaped, appears September 22nd in the journal Matter.
    “Like an insect with antennae, the robot can surmount a small obstacle. But when the obstacle is too high, it will turn back,” says senior author Wei Feng, a materials scientist at Tianjin University in China. “The whole process is spontaneous without human interference or control.”
    The robot starts off as a flat, rectangular sheet of a 3D-printed liquid crystal elastomer, a type of stretchy plastic material. When the surface beneath it is heated, the robot spontaneously twists up to form a tubule resembling a spring. The change in shape under external stimulation adds time as a fourth dimension to the printing process, making it 4D.
    Once the robot forms a tubule, the contact from the hot surface induces a strain in the material, which causes it to roll in one direction. The driving force behind this motion is so strong that the robot can climb up a 20° incline or even carry a load 40 times its own weight. The length of the robot affects its velocity, with longer robots rolling faster than their shorter counterparts.
    The researchers captured videos showing off the robot’s skills, including a race between differently sized robots and another robot carrying a cart. The videos also show how its behavior changes based on its surroundings, with the robot either climbing up a step or changing directions when encountering an insurmountable obstacle.
    For Feng, the behavior of the robot came as a surprise. “We processed the liquid crystal elastomers into samples of various shapes through 4D printing and stimulated these samples with light, heat, and electricity to observe their response,” he says. “We found many interesting driving phenomena besides deformation.”
    In the future, these soft robots may be used to perform work in small, confined places like in a pipe or under extreme conditions like a 200? surface. “We hope that soft robots will no longer be limited to simple actuators, which can only change shape in a fixed position,” says Feng.
    This work was supported by the State Key Program of National Natural Science Foundation of China, National Key R&D Program of China, and National Natural Science Foundation of China.
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    Materials provided by Cell Press. Note: Content may be edited for style and length. More

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    Winged microchip is smallest-ever human-made flying structure

    Northwestern University engineers have added a new capability to electronic microchips: flight.
    About the size of a grain of sand, the new flying microchip (or “microflier”) does not have a motor or engine. Instead, it catches flight on the wind — much like a maple tree’s propeller seed — and spins like a helicopter through the air toward the ground.
    By studying maple trees and other types of wind-dispersed seeds, the engineers optimized the microflier’s aerodynamics to ensure that it — when dropped at a high elevation — falls at a slow velocity in a controlled manner. This behavior stabilizes its flight, ensures dispersal over a broad area and increases the amount of time it interacts with the air, making it ideal for monitoring air pollution and airborne disease.
    As the smallest-ever human-made flying structures, these microfliers also can be packed with ultra-miniaturized technology, including sensors, power sources, antennas for wireless communication and embedded memory to store data.
    The research is featured on the cover of the Sept. 23 issue of Nature.
    “Our goal was to add winged flight to small-scale electronic systems, with the idea that these capabilities would allow us to distribute highly functional, miniaturized electronic devices to sense the environment for contamination monitoring, population surveillance or disease tracking,” said Northwestern’s John A. Rogers, who led the device’s development. “We were able to do that using ideas inspired by the biological world. Over the course of billions of years, nature has designed seeds with very sophisticated aerodynamics. We borrowed those design concepts, adapted them and applied them to electronic circuit platforms.”
    A pioneer in bioelectronics, Rogers is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery in the McCormick School of Engineeringand Feinberg School of Medicineand director of the Querrey Simpson Institute for Bioelectronics. Yonggang Huang, the Jan and Marcia Achenbach Professor of Mechanical Engineering at McCormick, led the study’s theoretical work. More

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    New machine learning method to analyze complex scientific data of proteins

    Scientists have developed a method using machine learning to better analyze data from a powerful scientific tool: nuclear magnetic resonance (NMR). One way NMR data can be used is to understand proteins and chemical reactions in the human body. NMR is closely related to magnetic resonance imaging (MRI) for medical diagnosis.
    NMR spectrometers allow scientists to characterize the structure of molecules, such as proteins, but it can take highly skilled human experts a significant amount of time to analyze that data. This new machine learning method can analyze the data much more quickly and just as accurately.
    In a study recently published in Nature Communications, the scientists described their process, which essentially teaches computers to untangle complex data about atomic-scale properties of proteins, parsing them into individual, readable images.
    “To be able to use these data, we need to separate them into features from different parts of the molecule and quantify their specific properties,” said Rafael Brüschweiler, senior author of the study, Ohio Research Scholar and a professor of chemistry and biochemistry at The Ohio State University. “And before this, it was very difficult to use computers to identify these individual features when they overlapped.”
    The process, developed by Dawei Li, lead author of the study and a research scientist at Ohio State’s Campus Chemical Instrument Center, teaches computers to scan images from NMR spectrometers. Those images, known as spectra, appear as hundreds and thousands of peaks and valleys, which, for example, can show changes to proteins or complex metabolite mixtures in a biological sample, such as blood or urine, at the atomic level. The NMR data give important information about a protein’s function and important clues about what is happening in a person’s body.
    But deconstructing the spectra into readable peaks can be difficult because often, the peaks overlap. The effect is almost like a mountain range, where closer, larger peaks obscure smaller ones that may also carry important information. More

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    Electrons on the edge: The story of an intrinsic magnetic topological insulator

    An intrinsic magnetic topological insulator MnBi2Te4 has been discovered with a large band gap, making it a promising material platform for fabricating ultra-low-energy electronics and observing exotic topological phenomena.
    Hosting both magnetism and topology, ultra-thin (only several nanometers in thickness) MnBi2Te4 was found to have a large band-gap in a Quantum Anomalous Hall (QAH) insulating state, where the material is metallic (ie, electrically conducting) along its one-dimensional edges, while electrically insulating in its interior. The almost zero resistance along the 1D edges of a QAH insulator, make it promising for lossless transport applications and ultra-low energy devices.
    HISTORY OF QAH: HOW TO ACHIEVE THE DESIRED EFFECT
    Previously, the path towards realising the QAH effect was to introduce dilute amounts of magnetic dopants into ultra-thin films of 3D topological insulators.
    However, dilute magnetic doping results in a random-distribution of magnetic impurities, causing non-uniform doping and magnetisation. This greatly suppresses the temperature at which the QAH effect can be observed and limits possible future applications.
    A simpler option is to use materials that host this electronic state of matter as an intrinsic property. More

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    Pioneering software can grow and treat virtual tumors using AI designed nanoparticles

    The EVONANO platform allows scientists to grow virtual tumours and use artificial intelligence to automatically optimise the design of nanoparticles to treat them.
    The ability to grow and treat virtual tumours is an important step towards developing new therapies for cancer. Importantly, scientists can use virtual tumours to optimise design of nanoparticle-based drugs before they are tested in the laboratory or patients.
    The paper, ‘Evolutionary computational platform for the automatic discovery of nanocarriers for cancer treatment,’ is published today in the Nature journal Computational Materials. The paper is the result of the European project EVONANO which involves Dr Sabine Hauert and Dr. Namid Stillman from the University of Bristol, and is led by Dr Igor Balaz at the University of Novi Sad.
    “Simulations enable us to test many treatments, very quickly, and for a large variety of tumours. We are still at the early stages of making virtual tumours, given the complex nature of the disease, but the hope is that even these simple digital tumours can help us more efficiently design nanomedicines for cancer,” said Dr Hauert.
    Dr Hauert said having the software to grow and treat virtual tumours could prove useful in the development of targeted cancer treatments.
    “In the future, creating a digital twin of a patient tumour could enable the design of new nanoparticle treatments specialised for their needs, without the need for extensive trial and error or laboratory work, which is often costly and limited in its ability to quickly iterate on solutions suited for individual patients,” said Dr Hauert. More

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    Tuning flexible circuits with light

    Researchers from SANKEN (The Institute of Scientific and Industrial Research) at Osaka University and JOANNEUM RESEARCH (Weiz, Austria), have shown how exposing an organic polymer to ultraviolet light can precisely modify its electronic properties. This work may aid in the commercialization of flexible electronics that can be used for real-time healthcare monitoring, along with data processing.
    While the integrated circuits inside your smart phone are quite impressive, they lack certain important features. Because the electronics are silicon based, they are very rigid, both in the literal sense of being inflexible, as well as having chemical properties that are not easily altered. Newer devices, including OLED displays, are made from carbon-based organic molecules with chemical properties than can be tuned by scientists to produce the most efficient circuits. However, controlling the characteristics of organic transistors usually requires the integration of complex structures made of various materials.
    Now, a team of researchers led by Osaka University have used UV light to precisely change the chemical structure of a dielectric polymer called PNDPE. The light breaks specific bonds in the polymer, which can then rearrange into new versions, or create crosslinks between strands. The longer the light is on, the more the polymer get altered. By using a shadow mask, the UV light is applied to just the desired areas, tuning the circuit behavior. This method can pattern transistors of the desired threshold voltage with high spatial resolution using just a single material.
    “We have succeeded in controlling the characteristics of organic integrated circuits using persistent light-induced changes in the molecular structure itself,” study corresponding author Takafumi Uemura explains.
    In the future, we may see smart versions of almost everything, from medicine bottles to safety vests. “Meeting the computational demands of ‘the Internet of Things’ will very likely require flexible electronic solutions,” senior author Tsuyoshi Sekitani says. In particular, this technology can be applied to manufacturing methods for ultra-lightweight wearable healthcare devices.
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    Materials provided by Osaka University. Note: Content may be edited for style and length. More

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    Novel assay finds new mechanism underlying red blood cell aging

    Red blood cells are the most abundant cell type in blood, carrying oxygen throughout the human body. In blood circulation, they repetitively encounter various levels of oxygen tension. Hypoxia, a low oxygen tension condition, is a very common micro-environmental factor in physiological processes of blood circulation and various pathological processes such as cancer, chronic inflammation, heart attacks and stroke. In addition, an interplay between poor cellular deformability and impaired oxygen delivery is found in various pathological processes such as sickle cell disease. Sickle red blood cells simultaneously undergo drastic mechanical deformation during the sickling and unsickling process.
    The interactions between hypoxia and cell biomechanics and the underlying biochemical mechanisms of the accelerated damage in diseased red blood cells are well understood, however, the exact biomechanical consequences of hypoxia contributing to red blood cell degradation (aging) remains elusive.
    Researchers from Florida Atlantic University’s College of Engineering and Computer Science, in collaboration with the Massachusetts Institute of Technology (MIT), sought to identify the role of hypoxia on red blood cell aging via the biomechanical pathways. In particular, they examined hypoxia-induced impairment of red blood cell deformability at the single cell level, compared the differences between non-cyclic hypoxia and cyclic hypoxia, and documented any cumulative effect vs. hypoxia cycles, such as aspects that have not been studied quantitatively. Red blood cell deformability is an important biomarker of its functionality.
    For the study, published in the journal Lab on a Chip, researchers developed a multifaceted microfluidic in vitro assay to precisely control the gaseous environment while probing the mechanical performance of red blood cells, which can be used as a characterization tool for other cell types involved in oxygen-dependent biological processes. The assay holds promise for investigating hypoxic effects on the metastatic potential and relevant drug resistance of cancer cells. Cancer cells are more metastatic in a hypoxic tumor microenvironment and cancer cell stiffness has been shown to be an effective biomarker of their metastatic potential.
    Findings from the study indicate an important biophysical mechanism underlying red blood cell aging in which the cyclic hypoxia challenge alone can lead to mechanical degradation of the red blood cell membrane. This process in combination with the deformation-induced mechanical fatigue represents two major fatigue loading conditions that circulating red blood cells experience.
    “A unique feature of our system lies in that the cell deformability measurement can be made on multiple, individually tracked red blood cells under a well-controlled oxygen tension environment,” said Sarah Du, Ph.D., senior author, an associate professor in FAU’s Department of Ocean and Mechanical Engineering, and a member of FAU’s Institute for Human Health and Disease Intervention (I-HEALTH). “Our results showed that the deformability of red blood cells decreases under deoxygenation conditions by before-and-after mechanical characterization of individual cells in response to the switching of oxygen levels within a microfluidic device.”
    Microfluidics serves as a miniaturized and efficient platform for gas diffusion by interfacing the gas and aqueous solution through flow or a gas-permeable membrane, which also is amenable to the control of the cellular gaseous microenvironment.
    For the study, researchers subjected red blood cells to a well-controlled repeated hypoxia microenvironment while allowing simultaneous characterization of the cell mechanical properties. They integrated an electro-deformation technique into a microdiffusion chamber, which was easy to implement and flexible in simultaneous applications of cyclic hypoxia challenge and shear stresses on individual cells in suspension and under quasi-stationary conditions.
    Measurements of biomarkers, such as oxidative damage, can provide additional information to establish quantitative relationships between the fatigue loading and the biological processes, allowing a better understanding of red blood cell failure and aging. The microfluidic assay also can be extended to study other types of biological cells for their mechanical performance and response to gaseous environments.
    “The unique method developed by professor Du’s lab also can be a useful tool to predict the mechanical performance of natural and artificial red blood cells for transfusion purposes as well as to assess the efficacy of relevant reagents in extending the cellular lifespan in circulation,” said Stella Batalama, Ph.D., dean, College of Engineering and Computer Science. “This promising and cutting-edge assay has the potential to further extend to red blood cells in other blood diseases and other cell types.”
    Study co-authors are Ming Dao, Ph.D., Department of Materials Science and Engineering, MIT; Yuhao Qiang, Ph.D., FAU College of Engineering and Computer Science and currently a postdoctoral researcher at MIT; and Jia Liu, Ph.D., FAU College of Engineering and Computer Science.
    This research is based on the materials supported by the National Science Foundation.
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    Materials provided by Florida Atlantic University. Original written by Gisele Galoustian. Note: Content may be edited for style and length. More