Showing posts with label Engineering. Show all posts
Showing posts with label Engineering. Show all posts

Friday, May 20, 2022

Neuromorphic Memory Device Simulates Neurons and Synapses​

A neuromorphic memory device consisting of bottom volatile and top nonvolatile memory layers emulating neuronal and synaptic properties, respectively
Credit: KAIST

Researchers have reported a nano-sized neuromorphic memory device that emulates neurons and synapses simultaneously in a unit cell, another step toward completing the goal of neuromorphic computing designed to rigorously mimic the human brain with semiconductor devices.

Neuromorphic computing aims to realize artificial intelligence (AI) by mimicking the mechanisms of neurons and synapses that make up the human brain. Inspired by the cognitive functions of the human brain that current computers cannot provide, neuromorphic devices have been widely investigated. However, current Complementary Metal-Oxide Semiconductor (CMOS)-based neuromorphic circuits simply connect artificial neurons and synapses without synergistic interactions, and the concomitant implementation of neurons and synapses still remains a challenge. To address these issues, a research team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering implemented the biological working mechanisms of humans by introducing the neuron-synapse interactions in a single memory cell, rather than the conventional approach of electrically connecting artificial neuronal and synaptic devices.

Boomerang’ effect in droplets could help clean sensitive surfaces

 A water-alcohol-propylene glycol droplet expands and then contracts, an effect that could be used to help remove particles from sensitive surfaces such as microchips.
Credit: Cornell University College of Engineering

While brooms and sponges are the means of choice to fight contamination in everyday life, cleaning sensitive surfaces such as electronic components require different tools, including evaporation-based methods that often leave behind small particles on the surface.

Through their work on the dynamics of liquid mixtures, scientists at Cornell’s Meinig School of Biomedical Engineering and the Max Planck Institute for Dynamics and Self-Organization have developed a new approach to the problem. The method uses liquid droplets that first spread out on surfaces and then contract again on their own – a boomerang effect that leaves virtually no traces when the droplets contract, unlike conventional drying, opening up new possibilities for cleaning and removing particles from sensitive surfaces such as microchips.

The missing piece to faster, cheaper and more accurate 3D mapping

The authors: Davide A. Cucci, Aurélien Brun and Jan Skaloud.
Credit: Alain Herzog/EPFL

Engineers at EPFL and the University of Geneva believe they hold the key to automated drone mapping. By combining artificial intelligence with a new algorithm, their method promises to considerably reduce the time and resources needed to accurately scan complex landscapes. It is described in a paper published in ISPRS Journal of Photogrammetry and Remote Sensing.

Three-dimensional (3D) mapping is a very useful tool for monitoring construction sites, tracking the effects of climate change on ecosystems and verifying the safety of roads and bridges. However, the technology currently used to automate the mapping process is limited, making it a long and costly endeavor.

“Switzerland is currently mapping its entire landscape using airborne laser scanners – the first time since 2000. But the process will take four to five years since the scanners have to fly at an altitude below one kilometer if they are to collect data with sufficient detail and accuracy,” says Jan Skaloud, a senior scientist at the Geodetic Engineering Laboratory (Topo) within EPFL's School of Architecture, Civil and Environmental Engineering (ENAC).

New breathable gas sensors may improve monitoring of health, environment

Huanyu “Larry” Cheng, assistant professor of engineering science and mechanics at Penn State, newly developed flexible, porous and highly sensitive nitrogen dioxide sensors that can be applied to skin and clothing.
Credit: Penn State/Kate Myers

Newly developed flexible, porous and highly sensitive nitrogen dioxide sensors that can be applied to skin and clothing have potential applications in health care, environmental health monitoring and military use, according to researchers.

Led by Huanyu “Larry” Cheng, assistant professor of engineering science and mechanics at Penn State, the researchers published their sensor designs, which build on previous models, and results in ACS Applied Materials and Interfaces.

The sensors monitor nitrogen dioxide, either from breath if attached under the nose, or from perspiration, if attached elsewhere on the body. Unlike taking blood samples, the direct skin attachment allows for continuous, long-term monitoring of the gas.

Cheng explained that while similar sensors exist, a key differentiator of the new design is breathability.

“The commonly used substrate materials for gas sensors are flexible, but not porous,” he said. “The accumulation of water moisture from the skin surface can potentially lead to irritation or damage to the skin surface. We need to make sure the device can be porous so that moisture can go through the sensor without accumulation on the surface.”

Thursday, May 19, 2022

Low-cost battery-like device absorbs CO2 emissions while it charges

Co-authors Israel Temprano and Grace Mapstone 
Credit: Gabriella Bocchetti

The supercapacitor device, which is similar to a rechargeable battery, is the size of a two-pence coin, and is made in part from sustainable materials including coconut shells and seawater.

Designed by researchers from the University of Cambridge, the supercapacitor could help power carbon capture and storage technologies at much lower cost. Around 35 billion tons of CO2 are released into the atmosphere per year and solutions are urgently needed to eliminate these emissions and address the climate crisis. The most advanced carbon capture technologies currently require large amounts of energy and are expensive.

The supercapacitor consists of two electrodes of positive and negative charge. In work led by Trevor Binford while completing his Master’s degree at Cambridge, the team tried alternating from a negative to a positive voltage to extend the charging time from previous experiments. This improved the supercapacitor’s ability to capture carbon.

“We found that that by slowly alternating the current between the plates we can capture double the amount of CO2 than before,” said Dr Alexander Forse from Cambridge’s Yusuf Hamied Department of Chemistry, who led the research.

Using Light and Sound to Reveal Rapid Brain Activity in Unprecedented Detail

The image shows the vasculature of the brain, and the colors illuminate how capillaries experience varying levels of oxygenation as the brain undergoes hypoxia.
Credit: Duke University

Duke researchers use a combination of hardware innovations and machine learning algorithms to create the fastest photoacoustic imaging tool available

Biomedical engineers at Duke University have developed a method to scan and image the blood flow and oxygen levels inside a mouse brain in real-time with enough resolution to view the activity of both individual vessels and the entire brain at once.

This new imaging approach breaks long-standing speed and resolution barriers in brain imaging technologies and could uncover new insights into neurovascular diseases like stroke, dementia and even acute brain injury.

The research appeared in the Nature journal Light: Science & Applications.

Imaging the brain is a balancing act. Tools need to be fast enough to capture rapid events, like a neuron firing or blood flowing through a capillary, and they need to show activity at different scales, whether it’s across the entire brain or at the level of a single artery.

Tuesday, May 17, 2022

Technology allows amputees to control a robotic arm with their mind

University of Minnesota Department of Biomedical Engineering Associate Professor Zhi Yang shakes hands with research participant Cameron Slavens, who tested out the researchers' robotic arm system. With the help of industry collaborators, the researchers have developed a way to tap into a patient’s brain signals through a neural chip implanted in the arm, effectively reading the patient’s mind and opening the door for less invasive alternatives to brain surgeries.
Credit: Neuroelectronics Lab, University of Minnesota

University of Minnesota Twin Cities researchers have developed a more accurate, less invasive technology that allows amputees to move a robotic arm using their brain signals instead of their muscles.

Many current commercial prosthetic limbs use a cable and harness system that is controlled by the shoulders or chest, and more advanced limbs use sensors to pick up on subtle muscle movements in a patient’s existing limb above the device. But both options can be cumbersome, unintuitive, and take months of practice for amputees to learn how to move them.

Researchers in the University’s Department of Biomedical Engineering, with the help of industry collaborators, have created a small, implantable device that attaches to the peripheral nerve in a person’s arm. When combined with an artificial intelligence computer and a robotic arm, the device can read and interpret brain signals, allowing upper limb amputees to control the arm using only their thoughts.

Tuesday, May 10, 2022

Hidden Distortions Trigger Promising Thermoelectric Property

Brookhaven Lab members of the research team: Simon Billinge, Milinda Abeykoon, and Emil Bozin adjust instruments for data collection at the Pair Distribution Function beamline of the National Synchrotron Light Source II. In this setup, a stream of hot air heats samples with degree-by-degree precision as x-rays collect data on how the material changes.
Credit: Brookhaven National Laboratory

In a world of materials that normally expand upon heating, one that shrinks along one 3D axis while expanding along another stands out. That’s especially true when the unusual shrinkage is linked to a property important for thermoelectric devices, which convert heat to electricity or electricity to heat.

In a paper just published in the journal Advanced Materials, a team of scientists from Northwestern University and the U.S. Department of Energy’s Brookhaven National Laboratory describe the previously hidden sub-nanoscale origins of both the unusual shrinkage and the exceptional thermoelectric properties in this material, silver gallium telluride (AgGaTe2). The discovery reveals a quantum mechanical twist on what drives the emergence of these properties—and opens up a completely new direction for searching for new high-performance thermoelectrics.

Friday, April 29, 2022

Fermilab engineers develop new control electronics for quantum computers that improve performance and cut costs

Gustavo Cancelo led a team of Fermilab engineers to create a new compact electronics board: It has the capabilities of an entire rack of equipment that is compatible with many designs of superconducting qubits at a fraction of the cost.
Photo: Ryan Postel, Fermilab

When designing a next-generation quantum computer, a surprisingly large problem is bridging the communication gap between the classical and quantum worlds. Such computers need specialized control and readout electronics to translate back and forth between the human operator and the quantum computer’s languages — but existing systems are cumbersome and expensive.

However, a new system of control and readout electronics, known as Quantum Instrumentation Control Kit, or QICK, developed by engineers at the U.S. Department of Energy’s Fermi National Accelerator Laboratory, has proved to drastically improve quantum computer performance while cutting the cost of control equipment.

“The development of the Quantum Instrumentation Control Kit is an excellent example of U.S. investment in joint quantum technology research with partnerships between industry, academia and government to accelerate pre-competitive quantum research and development technologies,” said Harriet Kung, DOE deputy director for science programs for the Office of Science and acting associate director of science for high-energy physics.

Engineers at UBC get under the skin of ionic skin

Dr. John Madden and Yuta Dobashi with one of the hydrogel sensors.
Photo by Kai Jacobson/UBC Faculty of Applied Science

In the quest to build smart skin that mimics the sensing capabilities of natural skin, ionic skins have shown significant advantages. They’re made of flexible, biocompatible hydrogels that use ions to carry an electrical charge. In contrast to smart skins made of plastics and metals, the hydrogels have the softness of natural skin. This offers a more natural feel to the prosthetic arm or robot hand they are mounted on, and makes them comfortable to wear.

These hydrogels can generate voltages when touched, but scientists did not clearly understand how — until a team of researchers at UBC devised a unique experiment, published in Science.

“How hydrogel sensors work is they produce voltages and currents in reaction to stimuli, such as pressure or touch – what we are calling a piezoionic effect. But we didn’t know exactly how these voltages are produced,” said the study’s lead author Yuta Dobashi, who started the work as part of his master’s in biomedical engineering at UBC.

Working under the supervision of UBC researcher Dr. John Madden, Dobashi devised hydrogel sensors containing salts with positive and negative ions of different sizes. He and collaborators in UBC’s physics and chemistry departments applied magnetic fields to track precisely how the ions moved when pressure was applied to the sensor.

Thursday, April 28, 2022

New Study Could Help Reduce Agricultural Greenhouse Gas Emissions

Researchers developed a first-of-its-kind knowledge-guided machine learning model for agroecosystem, called KGML-ag that includes less obvious variables such as soil water content, oxygen level, and soil nitrate content related to nitrous oxide production and emission.
Credit: University of Minnesota College of Science and Engineering

A team of researchers led by the University of Minnesota has significantly improved the performance of numerical predictions for agricultural nitrous oxide emissions. The first-of-its-kind knowledge-guided machine learning model is 1,000 times faster than current systems and could significantly reduce greenhouse gas emissions from agriculture.

The research was recently published in Geoscientific Model Development, a not-for-profit international scientific journal focused on numerical models of the Earth. Researchers involved were from the University of Minnesota, the University of Illinois at Urbana-Champaign, Lawrence Berkeley National Laboratory, and the University of Pittsburgh.

Compared to greenhouse gases such as carbon dioxide and methane, nitrous oxide is not as well-known. In reality, nitrous oxide is about 300 times more powerful than carbon dioxide in trapping heat in the atmosphere. Human-induced nitrous oxide emissions (mainly from agricultural synthetic fertilizer and cattle manure) have also grown by at least 30 percent over the past four decades.

Wednesday, April 27, 2022

New research provides better understanding of skin’s durability

Guy German is an associate professor at Binghamton University's biomedical engineering department. Image Credit: Jonathan Cohen.

As someone who has extensively studied what nature has produced, Associate Professor Guy German likes to tell his students: You think you’re a good engineer, but evolution is a better one.

Reinforcing this point is newly published research from German’s lab regarding the structure of human skin and the amount of damage it can sustain.

The paper, “Biomechanical fracture mechanics of composite layered skin-like materials,” was published in the journal Soft Matter. German co-authored the study with two former students from his lab, Christopher Maiorana, PhD ’21, and Rajeshwari Jotawar, MS ’21.

The team created membranes from polydimethylsiloxane (PDMS), an inert and nontoxic material used in biomedical research. They mimicked the structure of mammalian skin by covering a soft, compliant layer with a thinner, stiffer outer later.

The “artificial skin” then underwent a series of tests to see how much stress it could take to break. Under the pressure of a sharp or blunt rod, the samples indented to form huge divots before breaking. The researchers also made an interesting discovery.

Plastic-eating Enzyme Could Eliminate Billions of Tons of Landfill Waste

An enzyme variant created by engineers and scientists at The University of Texas at Austin can break down environment-throttling plastics that typically take centuries to degrade in just a matter of hours to days.

This discovery, published today in Nature, could help solve one of the world’s most pressing environmental problems: what to do with the billions of tons of plastic waste piling up in landfills and polluting our natural lands and water. The enzyme has the potential to supercharge recycling on a large scale that would allow major industries to reduce their environmental impact by recovering and reusing plastics at the molecular level.

“The possibilities are endless across industries to leverage this leading-edge recycling process,” said Hal Alper, professor in the McKetta Department of Chemical Engineering at UT Austin. “Beyond the obvious waste management industry, this also provides corporations from every sector the opportunity to take a lead in recycling their products. Through these more sustainable enzyme approaches, we can begin to envision a true circular plastics economy.”

The project focuses on polyethylene terephthalate (PET), a significant polymer found in most consumer packaging, including cookie containers, soda bottles, fruit and salad packaging, and certain fibers and textiles. It makes up 12% of all global waste.

Friday, April 8, 2022

Gel delivery enhances cancer treatment

As shown in this demonstration, the hydrogel can be easily injected through a needle and then rapidly self-heals after injection to form a solid-like gel. The needle in this image is a 21-gauge needle, a relevant size for human injection.
Image credit: Abigail K. Grosskopf

One cutting-edge cancer treatment exciting researchers today involves collecting and reprogramming a patient’s T cells – a special set of immune cells – then putting them back into the body ready to detect and destroy cancerous cells. Although effective for widespread blood cancers like leukemia, this method rarely succeeds at treating solid tumors.

Now, Stanford University engineers have developed a delivery method that enhances the “attack power” of the modified immune cells, called chimeric antigen receptor (CAR) T cells. Researchers add CAR-T cells and specialized signaling proteins to a hydrogel – a water-filled gel that has characteristics in common with biological tissues – and inject the substance next to a tumor. This gel provides a temporary environment inside the body where the immune cells multiply and activate in preparation to fight cancerous cells, according to a new study published April 8 in Science Advances. The gel acts like a leaky holding pen that pumps out activated CAR-T cells to continuously attack the tumor over time.

“A lot of the CAR-T cell field is focusing on how to make better cells themselves, but there is much less focus on how to make the cells more effective once in the body,” said Eric Appel, assistant professor of materials science and engineering at Stanford and senior author of the paper. “So, what we’re doing is totally complementary to all of the efforts to engineer better cells.”

Thursday, April 7, 2022

Engineered crystals could help computers run on less power

Researchers at the University of California, Berkeley, have created engineered crystal structures that display an unusual physical phenomenon known as negative capacitance. Incorporating this material into advanced silicon transistors could make computers more energy efficient.
Credit: UC Berkeley image by Ella Maru Studio

Computers may be growing smaller and more powerful, but they require a great deal of energy to operate. The total amount of energy the U.S. dedicates to computing has risen dramatically over the last decade and is quickly approaching that of other major sectors, like transportation.

In a study published online this week in the journal Nature, University of California, Berkeley, engineers describe a major breakthrough in the design of a component of transistors — the tiny electrical switches that form the building blocks of computers — that could significantly reduce their energy consumption without sacrificing speed, size or performance. The component, called the gate oxide, plays a key role in switching the transistor on and off.

“We have been able to show that our gate-oxide technology is better than commercially available transistors: What the trillion-dollar semiconductor industry can do today — we can essentially beat them,” said study senior author Sayeef Salahuddin, the TSMC Distinguished professor of Electrical Engineering and Computer Sciences at UC Berkeley.

This boost in efficiency is made possible by an effect called negative capacitance, which helps reduce the amount of voltage that is needed to store charge in a material. Salahuddin theoretically predicted the existence of negative capacitance in 2008 and first demonstrated the effect in a ferroelectric crystal in 2011.

Wednesday, April 6, 2022

New Polymer Membrane Tech Improves Efficiency of CO2 Capture

Image credit: Chris Robert.

Researchers have developed a new membrane technology that allows for more efficient removal of carbon dioxide (CO2) from mixed gases, such as emissions from power plants.

“To demonstrate the capability of our new membranes, we looked at mixtures of CO2 and nitrogen, because CO2/nitrogen dioxide mixtures are particularly relevant in the context of reducing greenhouse gas emissions from power plants,” says Rich Spontak, co-corresponding author of a paper on the work. “And we’ve demonstrated that we can vastly improve the selectivity of membranes to remove CO2 while retaining relatively high CO2 permeability.”

“We also looked at mixtures of CO2 and methane, which is important to the natural gas industry,” says Spontak, who is a Distinguished Professor of Chemical and Biomolecular Engineering and Professor of Materials Science & Engineering at North Carolina State University. “In addition, these CO2-filtering membranes can be used in any situation in which one needs to remove CO2 from mixed gases – whether it’s a biomedical application or scrubbing CO2 from the air in a submarine.”

Membranes are an attractive technology for removing CO2 from mixed gases because they do not take up much physical space, they can be made in a wide variety of sizes, and they can be easily replaced. The other technology that is often used for CO2 removal is chemical absorption, which involves bubbling mixed gases through a column that contains a liquid amine – which removes CO2 from the gas. However, absorption technologies have a significantly larger footprint, and liquid amines tend to be toxic and corrosive.

Tuesday, April 5, 2022

Boeing’s Spectrolab to Power NASA’s Roman Space Telescope

Spectrolab, Inc., a wholly owned subsidiary of Boeing, will build the solar cells and integrate solar panels for NASA’s Roman Space Telescope.
Credit: GSFC/SVS

Spectrolab, Inc., a wholly owned subsidiary of Boeing [NYSE: BA], will manufacture, integrate and test approximately 4,000 XTJ Prime solar cells for NASA’s Nancy Grace Roman Space Telescope.

“Using Spectrolab’s XTJ Prime solar cells, NASA will be able to maximize the Roman Space Telescope’s power generation, allowing greater data gathering capability while operating in a unique mission environment at the L2 Lagrange point,” said Tony Mueller, president of Spectrolab. “These cells leverage both heritage and high efficiency for the agency’s newest universe studying telescope.”

Spectrolab’s NeXt Triple Junction (XTJ) Prime solar cells will provide power to the telescope, including its two main instruments – the Wide Field Instrument and the Coronagraph Instrument – as well as the primary mirror that is 2.4 meters in diameter (7.9 feet), and is the same size as the Hubble Space Telescope's primary mirror. The solar array consists of six panels, each approximately 3m-by-2.5m and consists of 4,000 triple junction solar cells. Triple junction solar cells leverage multiple bandgaps tuned to different wavelengths of the solar spectrum, allowing higher efficiencies not possible with commercially available silicon solar cell technology.

Tuesday, March 29, 2022

New method purifies hydrogen from heavy carbon monoxide mixtures

Chris Arges (right), Penn State associate professor of chemical engineering, proposes using high-temperature proton-selective polymer electrolyte membranes, or PEMs, to separate hydrogen from other gases in an ACS Energy Letters paper. Co-author Deepra Bhattacharya, Penn State doctoral student in chemical engineering, is seen at left.
Credit: Kelby Hochreither/Penn State.

Refining metals, manufacturing fertilizers and powering fuel cells for heavy vehicles are all processes that require purified hydrogen. But purifying, or separating, that hydrogen from a mix of other gases can be difficult, with several steps. A research team led by Chris Arges, Penn State associate professor of chemical engineering, demonstrated that the process can be simplified using a pump outfitted with newly developed membrane materials.

The researchers used an electrochemical hydrogen pump to both separate and compress hydrogen with an 85% recovery rate from fuel gas mixtures known as syngas and 98.8% recovery rate from conventional water gas shift reactor exit stream — the highest value recorded. The team detailed their approach in ACS Energy Letters.

Traditional methods for hydrogen separations employ a water gas shift reactor, which involves an extra step, according to Arges. The water gas shift reactor first converts carbon monoxide into carbon dioxide, which is then sent through an absorption process to separate the hydrogen from it. Then, the purified hydrogen is pressurized using a compressor for immediate use or for storage.

Friday, March 25, 2022

Enhancing the electromechanical behavior of a flexible polymer

Qiming Zhang, distinguished professor of electrical engineering, led a team of researchers to develop a robust piezoelectric material that can convert mechanical stress into electricity.
Credit: Tyler Henderson/Penn State

Piezoelectric materials convert mechanical stress into electricity, or vice versa, and can be useful in sensors, actuators and many other applications. But implementing piezoelectrics in polymers — materials composed of molecular chains and commonly used in plastics, drugs and more — can be difficult, according to Qiming Zhang, distinguished professor of electrical engineering.

Zhang and a Penn State-led team of interdisciplinary researchers developed a polymer with robust piezoelectric effectiveness, resulting in 60% more efficient electricity generation than previous iterations. They published their results today (Mar. 25) in Science

“Historically, the electromechanics coupling of polymers has been very low,” Zhang said. “We set out to improve this because the relative softness of polymers makes them excellent candidates for soft sensors and actuators in a variety of areas, including biosensing, sonar, artificial muscles and more.”

To create the material, the researchers deliberately implemented chemical impurities into the polymer. This process, known as doping, allows researchers to tune the properties of a material to generate desirable effects — provided they integrate the correct number of impurities. Adding too little of a dopant could prevent the desired effect from initiating, while adding too much could introduce unwanted traits that hamper the material’s function.  

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Using Light and Sound to Reveal Rapid Brain Activity in Unprecedented Detail

The image shows the vasculature of the brain, and the colors illuminate how capillaries experience varying levels of oxygenation as the brai...

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