All posts by University of Maryland

Dust in Space

Post Syndicated from University of Maryland original

On Earth, no natural phenomenon is quite as dependable as gravity. Even a child playing on a beach knows that the sand she is excavating will just sit there in her trowel, pulled downward by this powerful force.

But on small, low-gravity celestial bodies like asteroids, the rules of gravity that we know so well no longer apply—at least, not in the ways that we’re used to. And that’s a problem for the scientists who collect samples of regolith, the dusty or pebbly material found on the surfaces of these bodies.

Asteroids are remnants of the early solar system: essentially chunks of material that did not become planets. Regolith samples from asteroids and other small celestial bodies are critical for researchers to better understand how the solar system began, and how it has evolved since.

“Gravity is so weak on the surface of these bodies that our intuition fails,” says Christine Hartzell, an assistant professor of aerospace engineering at the University of Maryland’s A. James Clark School of Engineering. “And there’s a large degree of uncertainty in which other forces are important, and how strong they are.”

In the absence of strong gravitational influences, even electrostatic forces that would be considered weak to negligible on Earth may hold outsized importance in space. Hartzell, a participating scientist on the OSIRIS-REx mission currently orbiting the asteroid Bennu, studies these electrostatic forces. A better understanding of electrostatic forces on particles improves understanding of the natural evolution of asteroids and helps inform the design of sampling methods and instruments on future asteroid exploration missions.

Electrostatic forces occur when oppositely charged particles interact with each other. This causes regolith particles to behave curiously in three ways.

First, they cause dusty particles that rub against each other to stick together, or clump. Second, dust exposed to the flow of charged particles from solar wind plasma can detach, or loft away from the surface, drawn to opposite charges in the solar wind flowing past. Third, particles can levitate after being kicked up by a small meteorite impact or blasted by a visiting spacecraft, because the electrostatic forces on those particles cancel out any gravitational pull.

And it’s possible that it’s not just tiny dust particles that may behave unusually—but larger grains, due to the extremely weak effects of gravity on asteroids, as well.

The catch, however, is that none of these behaviors have been directly observed in space, nor the forces causing them to occur measured there. Though Hartzell’s work has demonstrated these forces in laboratory experiments, many questions remain about what they look like on an asteroid, to what degree electrostatic forces affect dust behavior, how strong those forces are, and how the presence of a spacecraft in close proximity to an asteroid’s surface might change the environment.

Whether or not lofting occurs depends on the strength of the forces causing particles to stick together and, by extension, to other objects, such as spacecraft surfaces and optics. Hartzell is developing an experimental method to measure this cohesion.

How the method will work: an electrically charged plate is placed at a set distance above a surface with dusty particles, in an area of known gravity. By controlling the height and electrical charge of the plate, the electrostatic forces on the dust grains can be controlled. A camera is used to observe the size of dust grains and when they begin to be drawn to the plate. By controlling the electrostatic force and knowing the gravity, the unknown, cohesive force can be mathematically derived.

Hartzell’s method could potentially be used for actual sampling, as well. She suggests that charged plates could be used to attract dust samples, then drop them into sample collectors or directly onto analysis instruments by removing the plate’s charge.

More likely, however, is that the method might be employed to better characterize the surface of a site intended for longer-term use by, for example, an asteroid mining mission. Early planning stages would involve understanding the chemistry and behavior of any dusty surface, including how its cohesive properties may affect the function of tools like drill bits.

Harnessing electrostatic forces to control dusty particles might also mean cleaner, better functioning solar panels on Mars. An electrostatic dust shield could use coils embedded in solar arrays to “bounce” dust grains off the surface via alternating electrical charges.

But for now, Hartzell’s work involves a lot of creative lab experimentation and lab-based modeling, but with one goal in mind.

“We want to keep the spacecraft safe during operations,” she says.

Envisioning the Future of Urban Transportation

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Growing urbanization around the globe is creating increasingly difficult challenges in areas of transportation and energy, but engineers at the University of Maryland (UMD) think there are solutions in the promise of electric vertical takeoff and landing (eVTOL) aircraft.

Just a decade ago, the idea of air taxies and cityscapes equipped with “verti-port” stations may have seemed like the latest science fiction, but with the technical advances and commercial success of electric vehicles, eyes are turning to the sky to see how similar ideas of electric power and propulsion could create a new generation of lightweight air vehicles capable of moving people quietly, safely, and efficiently in dense urban environments.

“eVTOL has many advantages over traditional helicopters,” explains Anubhav Datta, an associate professor in UMD’s A. James Clark School of Engineering. “They don’t cause the pollution of traditional engines, have no engine noise, require fewer mechanical parts, and depending on the design could be easier to fly and more responsive to autonomy.”

While eVTOL technology is in its infancy, Datta has been involved from the start. He published the first peer-reviewed journal article demonstrating the viability of eVTOL by presenting conceptual designs for three all-electric options for a manned ultralight utility helicopter, and anticipating growth of the field. Since then, he has been instrumental in spearheading efforts to expand basic research in eVTOL, create pools of technical knowledge, and develop multidisciplinary education and outreach programs.

At Maryland, Datta and his graduate students are pursuing several projects addressing some of the principal barriers that prevent eVTOL from becoming a day-to-day reality.

One major barrier to eVTOL success is developing lightweight on-board electrical energy storage systems that would allow these aircraft to fly for longer periods with adequate reserves. According to Datta, lithium-ion batteries built for consumer electronics and automobiles are too low-energy to be a long-term solution. Batteries must be built to meet VTOL requirements or alternative sources of power explored, such as the work of Ph.D. student Emily Fisler, who is trying to quantify these requirements and explore more advanced chemistries for future batteries.

Datta, along with students Wanyi Ng and Mrinal Patil, are also exploring the application of hydrogen in fuel cells as a renewable and clean energy source. Hydrogen gas can store four to five times as much energy as current batteries, but the high power fuel stacks are heavy—so Datta’s team is looking at ways to maximize the energy benefits of hydrogen by using supplemental batteries to boost output during high-power loads, such as takeoff and landing.

Since 2017, UMD’s Department of Aerospace Engineering has won two multi-year research tasks on eVTOL funded jointly by the U.S. Army, NASA, and the U.S. Navy. As part of this work, Ph.D. student Brent Mills has built a unique hybrid-electric engine—capable of powering a scaled-down 50-pound VTOL aircraft to test and acquire data on electro-aero-mechanical behavior of the engine. Aircraft designers of the future can use this data in conceptualizing and building vehicles.

A key advantage of electric drives is that they do not require heavy, interconnecting mechanical shafts to drive more than one rotor. While multiple rotors are less efficient, they make an aircraft more stable and maneuverable, which could possibly reduce training times for future pilots and make them safer to operate in urban environments. In addition, being easier to control makes them more receptive to autonomous operation.

According to Datta, one critical advantage to UMD’s eVTOL research is the university’s historic Glenn L. Martin Wind Tunnel. Constructed in 1949, it is one of only a few tunnels its size on a university campus. This facility enables them to acquire truth-data from direct observation that is critical to the safe design of advanced rotorcraft, yet far beyond what the best computational tools can predict. Special-purpose rigs are needed to carry out model tests in the tunnel.

One such rig is the Maryland Tiltrotor Rig (MTR). Designed to study the aeromechanics of advanced prop-rotors and wing combinations, the MTR has a direct electric drive on the pylon so that data collected in the course of the project can also be applied to eVTOL. The MTR can test up to 4.75-foot diameter Mach-scaled rotors, features interchangeable blades and hubs turning at 2,500 revolutions per minute, and has interchangeable spars that can change the wing behavior.

“It is the only test rig of its kind on a university campus,” says Datta, “and the Ph.D. students who developed it are laying the foundations of the future of tiltrotor and eVTOL research at Maryland for the next decade.”

Datta was a member of the American Helicopter Society’s (AHS) inaugural eVTOL workshop in 2014, chaired the NASA Aeronautics Research Institute’s (NARI) Transformative Vertical Flight working group on intra-city Urban Air Mobility in 2016, and led the AHS in establishing eVTOL as a distinct technical discipline by founding the eVTOL Technical Committee in 2019. Chaired by Datta, this committee includes technical leaders from across industry, government, and several UMD alumni who have become leaders in the field of rotorcraft.

As part of these efforts, Datta, with support from the Vertical Flight Society (VFS, formerly AHS) and NASA, created the first formal education course in eVTOL now taught annually at the VFS Forum and the American Institute of Aeronautics and Astronautics (AIAA) Aviation forum.

Datta believes that the promise of better utilization of airspace through eVTOL advancements could bring about more energy efficient transportation solutions, but there is a lot of research and expertise that still needs to be developed to propel this new field forward.  

“Through research efforts here at Maryland, we are not just building the future of eVTOL,” Datta says, “but we are providing opportunities for students to become the next generation of engineers that will have the knowledge and hands-on expertise to go out and be major contributors to that field.”

4D Bioprinting Smart Constructs for the Heart

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Cardiovascular disease is the leading cause of mortality worldwide, accounting for nearly 18 million deaths each year, according to the World Health Organization. In recent years, scientists have looked to regenerative therapies – including those that use 3D-printed tissue – to repair damage done to the heart and restore cardiac function.

Thanks to advancements in 3D-printing technology, engineers have applied cutting-edge bioprinting techniques to create scaffolds and cardiac tissue that, once implanted, can quickly integrate with native tissues in the body. While 3D bioprinting can create 3D structures made of living cells, the final product is static – it cannot grow or change in response to changes in its environment.

Conversely, in 4D bioprinting, time is the fourth dimension. Engineers apply 4D printing strategies to create constructs using biocompatible, responsive materials or cells that can grow or even change functionalities over time and in response to their environment. This technology could be a game-changer for human health, particularly in pediatrics, where 4D-printed constructs could grow and change as children age, eliminating the need for future surgeries to replace tissues or scaffolds that fail to do the same.

But, 4D bioprinting technology is still young. One of the critical challenges impacting the field is the lack of advanced 4D-printable bioinks – material used to produce engineered live tissue using printing technology – that not only meet the requirements of 3D bioprinting, but also feature smart, dynamic capabilities to regulate cell behaviors and respond to changes in the environment wherever they’re implanted in the body.

Recognizing this, researchers at George Washington University (GWU) and the University of Maryland’s A. James Clark School of Engineering are working together to shed new light on this burgeoning field. GWU Department of Mechanical and Aerospace Engineering Associate Professor Lijie Grace Zhang and UMD Fischell Department of Bioengineering Professor and Chair John Fisher were recently awarded a joint $550,000 grant from the National Science Foundation to investigate 4D bioprinting of smart constructs for cardiovascular study.  

Their main goal is to design novel and reprogrammable smart bioinks that can create dynamic 4D-bioprinted constructs to repair and control the muscle cells that make up the heart and pump blood throughout the body. The muscle cells they’re working with – human induced pluripotent stem cell (iPSC) derived cardiomyocytes – represent a promising stem cell source for cardiovascular regeneration.

In this study, the bioinks, and the 4D structures they’re used to create, are considered “reprogrammable” because they can be precisely controlled by external stimuli – in this case, by light – to contract and elongate on command in the same way that native heart muscle cells do with each and every heartbeat.

The research duo will use long-wavelength near-infrared (NIR) light to serve as the stimulus that prompts the 4D bioprinted structures into action. Unlike ultraviolet or visible light, long-wavelength NIR light could efficiently penetrate the bioprinted structures without causing harm to surrounding cells.

“4D bioprinting is at the frontier of the field of bioprinting,” Zhang said. “This collaborative research will expand our fundamental understanding of iPSC cardiomyocyte development in a dynamic microenvironment for cardiac applications. We are looking forward to a fruitful collaboration between our labs in the coming years.” 

“We are thrilled to work with Dr. Zhang and her lab to continue to develop novel bioinks for 3D- and 4D- printing,” Fisher said. “We are confident that the collaborative research team will continue to bring to light untapped printing strategies, particularly in regards to stem cell biology.” 

Moving forward, Zhang and Fisher hope to apply their 4D bioprinting technique to further study of the fundamental interactions between 4D structures and cardiomyocyte behaviors.

“The very concept of 4D bioprinting is so new that it opens up a realm of possibilities in tissue engineering that few had ever imagined,” Fisher said. “While scientists and engineers have a lot of ground to cover, 4D bioprinted tissue could one day change how we treat pediatric heart disease, or even pave the way to alternatives to donor organs.”

At GWU, Zhang leads the Bioengineering Laboratory for Nanomedicine and Tissue Engineering. At UMD, Fisher leads the Center for Engineering Complex Tissues, a joint research collaboration between UMD, Rice University, and the Wake Forest Institute for Regenerative Medicine. Fisher is also the principal investigator of the Tissue Engineering and Biomaterials Lab, housed within the UMD Fischell Department of Bioengineering.

Amazon Rainforest: Reversing the Damage from Mercury Poisoning

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Catastrophic wildfires that ravaged parts of the Amazon rainforest this summer represent only one of the numerous threats facing a region that some dub “the world’s lungs.” Mercury poisoning linked to illegal gold mining operations has also caused widespread destruction, with over 100,000 ha lost over the past two decades.

Restoring the poisoned rainforest requires more precise data about toxicity levels than is currently available. Research being conducted by Maria Rodriguez, a doctoral candidate in environmental engineering at the University of Maryland’s A. James Clark School of Engineering, aims to obtain that data.

Gold miners use mercury to help identify and extract gold, applying it to soil and river sandbanks and later burning the mix to isolate the treasured metal. The technique brings about long-term contamination that has turned once-verdant rainforest into a desert landscape. 

“More than 100,000 hectares have been deforested in Peru alone over the past 20 years” as a result of artisanal gold mining,” Rodriguez notes.

In addition to the loss of rainforest—a phenomenon that exacerbates global warming—the use of mercury poses health hazards to local people who ingest the affected plants. It also impacts farmers, because the exposure of plants to mercury can lower crop yields.

This summer, Rodriguez and her faculty mentors, Natasha Andrade and Alba Torrents, traveled to Peru to assist the environment ministry and the regional conservation NGO CINCIA, which is working to counter deforestation and bring about environmental restoration. Repairing the damage requires scientific analysis of the impact, and that’s where Rodriguez—who was awarded an International Graduate Research Fellowship that supported her initial on-site research—hopes to make a difference. She plans to return next summer to continue her work.

Reforestation efforts up until now have been hampered by insufficient data, she explained.

“There’s a program under way to reclaim the contaminated areas using a number of indigenous plant species that provide ecosystem services, like food or COcapture. But we don’t know enough about the level of contamination in the soil and air and how it affects these particular species. We can’t determine if the concentration of mercury in the soil will harm the plants unless we know the levels at which mercury becomes toxic for them. No studies currently exist with regard to these indigenous plants,” she said.

Rodriguez aims to fill in these gaps in the research by determining the toxicity reference value—in simple terms, a way of measuring the threshold for harmful exposure—of several species, including the plants commonly known as achiote, cocona, and yuca.

Her endeavor has the potential to shed light on a number of specific questions that are important for conservation and recovery efforts. 

“Through tests and analysis, we can determine, for instance, which plant species are more likely to grow in the degraded soil. We can determine the extent to which the soil needs to be cleared before replanting, and we can make predictions about tree growth,” Rodriguez said.

“By obtaining this information and sharing it with CINCIA and the environment ministry, we hope to assist in strengthening the conservation effort,” she said.

“The political will exists to take action to recover these areas, but data is needed for the effort to be successful.”

Making “Smart” Cells Smarter

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For years, scientists have explored ways to alter the cells of microorganisms in efforts to improve how a wide range of products are made – including medicines, fuels, and even beer. By tapping into the world of metabolic engineering, researchers have also developed techniques to create “smart” bacteria capable of carrying out a multitude of functions that impact processes involved in drug delivery, digestion, and even water decontamination.

But, altering the genetic and regulatory processes that take place within cells presents challenges.

To start, cells are already programmed to carry out their normal, everyday processes with maximum efficiency; any alterations that engineers make to increase a cell’s production of a certain substance can, in turn, upset these processes and overburden the cell.

To address this problem, William E. Bentley, an A. James Clark School of Engineering professor and director of the Robert E. Fischell Institute for Biomedical Devices, is working with a team of researchers to focus on engineering microbial consortia, wherein cell subpopulations are engineered to work together to carry out a desired function. This strategy – which others in the field have also explored – allows engineers to design specialized cells and divvy up the target workload among a group of cells.

The tradeoff is that directing a cell consortium to carry out specific tasks requires engineers to somehow regulate how many of each cell subpopulation are present. Until now, there’s been little research focused on developing devices or systems to automatically regulate the compositions of cellular subpopulations within a consortium. Generally, studies of cell consortia have required engineers to use painstaking manual or expensive external controller systems to strike that balance.

Bentley and his team are focused on reengineering cells so that they’re able to coordinate their subpopulation densities autonomously. Their technique was highlighted in a Nature Communications paper published on Sept. 11.

“The key concept is that groups of cells can be engineered to self-regulate their composition, and no outside input is needed,” Bentley said. “For example, there’s no way to ensure that the bacteria engineered for use in the gastrointestinal tract will actually be retained or behave as we expect. And you can’t use convenient means such as magnetic or electrical fields to regulate bacteria in the gut, so why not incorporate the self-regulation property into the bacteria themselves?”

Like others in the field, Bentley and members of his Biomolecular and Metabolic Engineering Lab previously investigated “quorum sensing,” or QS—a bacterial form of cell-to-cell communication—to engineer communication circuits between bacterial strains to coordinate their behaviors.

To create an autonomous system, Bentley and his team rewired the bacterial QS systems in two strains of E. coli so that the growth rate of communicating cell subpopulations within the consortia would be dictated by signaling between the cells. It’s a sort of feedback loop in which cells are able to sense and react to intercellular signaling molecules called autoinducers, which enable bacteria to work together of their own accord.

The breakthrough could be key to a host of new functions for “smart bacteria” developed through genetic engineering, ranging from drug delivery to water decontamination to new fermentation processes for the latest craft beverage.

“Increasingly, consortia of microbes will be tasked with converting raw materials into valuable products,” Bentley said. “The raw materials may be wastes or byproducts of industrial processes. The synthetic capabilities of consortia may far surpass those of pure monocultures, so methodologies that help to align consortia will be needed.”

University of Maryland Fischell Department of Bioengineering (BIOE) and Institute for Bioscience and Biotechnology Research (IBBR) researcher Kristina Stephens served as first author on the Nature Communications paper titled, “Bacterial co-culture with cell signaling translator and growth controller modules for autonomously regulated culture composition.” Maria Pozo (BIOE), Chen-Yu Tsao (BIOE, IBBR), and Pricila Hauk (BIOE, IBBR) also contributed to the paper.

This work is supported in part by funding from the National Science Foundation, the Defense Threat Reduction Agency (U.S. Department of Defense), and the National Institutes of Health (NIH).

Delivering on Quantum Innovation

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The University of Maryland (UMD) has announced the launch of the Quantum Technology Center (QTC), which aims to translate quantum physics research into innovative technologies.

The center will capitalize on the university’s strong research programs and partnerships in quantum science and systems engineering, and pursue collaborations with industry and government labs to help take promising quantum advances from the lab to the marketplace. QTC will also train students in the development and application of quantum technologies to produce a workforce educated in quantum-related engineering.

The launch of QTC comes at a pivotal time when quantum science research is expanding beyond physics into materials science, engineering, computer science, chemistry, and biology. Scientists across these disciplines are looking for ways to exploit quantum physics to build powerful computers, develop secure communication networks, and improve sensing and imaging capabilities. In the future, quantum technology could also impact fields such as artificial intelligence, energy, and medicine.

Fearless vision

The rules of quantum physics cover the shockingly strange behaviors of atoms and smaller particles. Technologies based on the first century of quantum physics research are close at hand in your daily life—in your smartphone’s billions of transistors and GPS navigation, for instance.

Today more radical quantum technologies are moving toward commercial reality.

UMD has long been a powerhouse in quantum research and is now accelerating this trend with the launch of QTC. Founded jointly by UMD’s A. James Clark School of Engineering and College of Computer, Mathematical, and Natural Sciences, QTC will translate quantum science to the marketplace.

“QTC will be a community that brings together different types of people and ideas to create new quantum technologies and train a new generation of quantum workforce,” says QTC founding Director Ronald Walsworth. “UMD will focus on developing these technologies in the early stages, and then translating them out to the wider world with diverse partners.”

Like UMD’s existing quantum research programs, QTC is expected to draw strong sponsorship from federal research agencies. National support for quantum research is on the upswing—most notably evidenced by the National Quantum Initiative, signed into law in December 2018, which authorizes $1.275 billion over five years for research. 

Quantum research on the rise

UMD already hosts more than 200 researchers in quantum science, one of the greatest concentrations in the world. Much of the effort has been led by the Joint Quantum Institute (JQI) and Joint Center for Quantum Information and Computer Science (QuICS), both partnerships between UMD and the National Institute of Standards and Technology. JQI and QuICS support many projects that cross boundaries in research disciplines and organizations; this trend will only increase with QTC on campus.

One prime example of constructively blurred lines comes from the research of Distinguished University Professor Chris Monroe. An international leader in isolating individual atoms for quantum computing and simulation, Monroe is a member of all three centers, and well-positioned to tap into the expertise of researchers in related disciplines. 

Professor Edo Waks and Associate Professor Mohammad Hafezi, both members of QTC and JQI, are also among the UMD researchers helping to form the next revolution of quantum research with groundbreaking work on devices for quantum information processing and quantum networks.

In one effort, Waks demonstrated the first single-photon transistor using a semiconductor chip. The device is compact; roughly one million of these new transistors could fit inside a single grain of salt. It is also fast and able to process 10 billion photonic qubits every second.

“Using our transistor, we should be able to perform quantum gates between photons,” says Waks. “Software running on a quantum computer would use a series of such operations to attain exponential speedup for certain computational problems.”

Hafezi studies the fundamental behaviors of light–matter interactions down to the single-photon level. He created the first silicon chip that can reliably constrain light to its four corners. The effect, which arises from interfering optical pathways, could eventually enable the creation of robust sources of quantum light.

“We have been developing integrated silicon photonic systems to realize ideas derived from topology in a physical system,” Hafezi says. “The fact that we use components compatible with current technology means that, if these systems are robust, they could possibly be translated into immediate applications.”

Grounding a quantum community

 “QTC will be a crucible for quantum science and engineering,” says Walsworth, a leader in quantum sensing who was recruited from Harvard University to lead the new center. “We’ll be building bridges between people, between sectors, between theories and technologies. There’s a kind of hunger for a community that pulls people together to pool information and find ways to overcome challenges in this exciting new area.”

According to Clark School Dean and Farvardin Professor Darryll Pines, UMD’s hiring of Walsworth signals an important next step in bringing engineering solutions to the forefront. “He’s the perfect representative to bridge the gap between physics and engineering, because he’s already been doing that himself,” says Pines.

In addition to his broad range of research accomplishments, Walsworth has acted as an advisor for corporations and co-founded two companies based in part on his lab’s work. Quantum Diamond Technologies is developing applications in medical diagnostics for quantum measurement technologies that can be generated at room temperatures in synthetic diamonds. Hyperfine Research is creating low-cost portable MRI machines. 

“If you really want a new community of technology to flourish, you’ve got to have the applications right,” Walsworth adds. “You’ve got to be solving someone’s problems. Some people are busy building their technologies, but they don’t always know what the technologies are good for. Other people are out there complaining about how they can’t solve their problems, but they don’t know what technology exists that might help.” 

Making the match will require QTC researchers to seek out groups across and outside the university to talk about actual challenges where quantum technology might help.

“From a United States perspective, this is a big deal,” he says. “Quantum is one of those areas that requires enormous investment from the federal government, to advance our knowledge in this space. We hope this leads to opportunities that translate to real products with positive impact for people, society, and the U.S. economy.”

Saving Lives…With Robots

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University of Maryland engineer wants to equip ambulances with medical robots enhanced by machine learning to help trauma patients

At the moment of traumatic injury, no physician is present. Emergency medical technicians respond first—they stabilize the patient during ambulance transport, while specialized trauma teams prepare to receive the patient at a hospital.

That is, if the patient makes it there.

“The ride to the hospital is the riskiest part for the trauma patient,” says Axel Krieger, assistant professor of mechanical engineering at the University of Maryland, who specializes in medical robotics and computer vision. Krieger says that estimates suggest one-third of trauma fatalities likely would have survived if they had access to hospital-level of care sooner. He aims to help make that level of care standard on the ambulance ride—a long way from his undergraduate days in Germany, where he studied automotive engineering.

To improve the health-giving capacity for trauma patients during the ambulance ride, Krieger wants to equip the ambulance with a medical robot enhanced by machine learning (ML). “One of the biggest dangers during the ambulance ride is undiagnosed, internal hemorrhagic bleeding,” he says. “It’s currently undetectable with methods available on the ambulance ride. You can’t see it.”

But a robot can.

“Imagine you have a patient in the emergency vehicle, and a robot scans the patient and obtains ultrasound images,” says Krieger, who is a member of the Maryland Robotics Center. “This can provide a critical level of life-saving diagnosis and care not yet possible during an emergency ambulance ride.”

The robot scans and visualizes the injury, then compares and analyzes the scans with its ML algorithm—which was trained using data from similar real-life patient images. It focuses on anatomic areas known to be especially vulnerable to hidden injury and bleeding—such as the pelvic area and space between the lungs, spleen, and liver—to determine severity of wounds based on location, depth, and interaction with vital anatomy; compute volume of blood loss; and assess hemorrhagic potential. Analyzing these characteristics en route would help produce an injury profile useful in triaging the patient so he or she can receive appropriate care as soon as possible—perhaps in the ambulance, and most certainly upon arrival at the hospital.

To develop this ML-based intelligent scanning robot, Krieger and several A. James Clark School of Engineering graduate students collaborated with trauma experts at the University of Maryland Medical Center’s R Adams Cowley Shock Trauma Center.

The research is still experimental and not yet approved for clinical use with patients—but Krieger believes it will be soon.

“It’s the translational aspect to patient care that really excites me,” he says. “If we can help more people survive, this is the best use of our work.”

Algorithms and Autonomous Discovery

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Materials scientist Ichiro Takeuchi uses machine learning-based discovery to help develop new, alternative materials

More than a decade ago, Ichiro Takeuchi, professor of materials science and engineering, started applying the subfield of artificial intelligence (AI) known as machine learning (ML) to help develop new magnetic materials.

At the time, ML was not widely used in materials science. “Now, it’s all the rage,” says Takeuchi, who also holds an appointment with the Maryland Energy Innovation Institute. Its current popularity is due in part to the deep learning revolution of 2012 and related advances in computer chip speed, data storage options, and rapid refinement of the science that drives its predictive analytics of algorithms.

ML-based discovery in materials science is not just a lab exercise. It can provide production solutions to geopolitical challenges—as in the case of deteriorating trade with China about a decade ago, which prompted a supply-chain crisis for electric vehicle motor development in the U.S. Key materials were no longer available to American producers to make the neodymium rare-earth permanent magnet that helps power the vehicles.

The solution: Takeuchi’s team applied ML to discover and develop new, alternative magnet materials so research for electric vehicle motors could continue.

And they bootstrapped it. In the beginning, Takeuchi and his team didn’t have any curated data to feed their ML algorithm. So they built the database themselves. They taught machines to read troves of scientific papers and parse data in search of patterns and predictions. From those papers, they extracted meaningful chemical details on rare-earth magnet performance, properties, and functions. This became the database they needed to enlist the aid of yet another ML algorithm. This time, the task was to identify alternative candidate materials with the desired traits for fabricating rare-earth permanent magnets.

According to Takeuchi, researchers increasingly search for novel materials with specific attributes. “ML helps us in our searches in a way that is computationally inexpensive and highly efficient, so we can understand composition–structure relationships and functional properties.’’

In Takeuchi’s lab, searches for new materials are done with accelerated synthesis of large numbers of compounds called high-throughput experiments, which produce up to 1,000 materials at a time and generate immense quantities of data. “We were inundated with data,” Takeuchi says. Yet prior to applying ML, they lacked a means for leveraging of all that data potential.

ML not only makes sense of enormous datasets—it extends discovery by allowing the algorithm to make predictions from “leads” it discovers in the data. The machine automatically discovers hidden relationships between materials and their properties, which is the knowledge Takeuchi and his team are ultimately seeking.

Takeuchi’s lab continues to innovate with ML-based discovery. Their newest development sprang from the question: “In the search to discover new materials with particular attributes, why don’t we let the computer analyze all the attributes and decide how the experiment should run?”

This new model of autonomous active learning is fast, inexpensive, and highly efficient, because the power and predictive ability of ML minimizes the number of experiments required to solve a problem.

“With an autonomous active learning approach, you don’t need to do 1,000 experiments as we did with high-throughput approaches,” Takeuchi says. “We need only to do about one-tenth or one-fifth of all experiments, because we let the algorithm decide where to go next. You see what the machine comes up with—without you. It predicts, and then we test. We think this is the future.”

Shedding Light on the Future of LASIK

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A University of Maryland-developed microscopy technique could eliminate the “surgery” aspect of LASIK

Fischell Department of Bioengineering (BIOE) researchers have developed a microscopy technique that could one day be used to improve LASIK and eliminate the “surgery” aspect of the procedure. Their findings were published in March in Physical Review Letters.

In the 20 years since the FDA first approved LASIK surgery, more than 10 million Americans have had the procedure done to correct their vision. When performed on both eyes, the entire procedure takes about 20 minutes and can rid patients of the need to wear glasses or contact lenses.

While LASIK has a very high success rate, virtually every procedure involves an element of guesswork. This is because doctors have no way to precisely measure the refractive properties of the eye. Instead, they rely heavily on approximations that correlate with the patient’s vision acuity—how close to 20/20 he or she can see without the aid of glasses or contacts.

In search of a solution, BIOE Assistant Professor Giuliano Scarcelli and members of his Optics Biotech Laboratory have developed a microscopy technique that could allow doctors to perform LASIK using precise measurements of how the eye focuses light, instead of approximations.

“This could represent a tremendous first for LASIK and other refractive procedures,” Scarcelli said. “Light is focused by the eye’s cornea because of its shape and what is known as its refractive index. But until now, we could only measure its shape. Thus, today’s refractive procedures rely solely on observed changes to the cornea, and they are not always accurate.”

The cornea—the outermost layer of the eye—functions like a window that controls and focuses light that enters the eye. When light strikes the cornea, it is bent—or refracted. The lens then fine-tunes the light’s path to produce a sharp image onto the retina, which converts the light into electrical impulses that are interpreted by the brain as images. Common vision problems, such as nearsightedness or farsightedness, are caused by the eye’s inability to sharply focus an image onto the retina.

To fix this, LASIK surgeons use lasers to alter the shape of the cornea and change its focal point. But, they do this without any ability to precisely measure how much the path of light is bent when it enters the cornea. 

To measure the path light takes, one needs to measure a quantity known as the refractive index; it represents the ratio of the velocity of light in a vacuum to its velocity in a particular material.

By mapping the distribution and variations of the local refractive index within the eye, doctors would know the precise degree of corneal refraction. Equipped with this information, they could better tailor the LASIK procedure such that, rather than improved vision, patients could expect to walk away with perfect vision—or vision that tops 20/20.

Even more, doctors might no longer need to cut into the cornea.

“Non-ablative technologies are already being developed to change the refractive index of the cornea, locally, using a laser,” Scarcelli said. “Providing local refractive index measurements will be critical for their success.”

Knowing this, Scarcelli and his team developed a microscopy technique that can measure the local refractive index using Brillouin spectroscopy—a light-scattering technology that was previously used to sense the mechanical properties of tissue and cells without disrupting or destroying either.

“We experimentally demonstrated that, by using a dual Brillouin scattering technology, we could determine the refractive index directly, while achieving three-dimensional spatial resolution,” Scarcelli said. “This means that we could measure the refractive index of cells and tissue at locations in the body—such as the eyes—that can only be accessed from one side.”

In addition to measuring corneal or lens refraction, the group is working on improving its resolution to analyze mass density behavior in cell biology or even cancer pathogenesis, Scarcelli said.

Along with Scarcelli, BIOE Ph.D. student Antonio Fiore (first author) and Carlo Bevilacqua, a visiting student from the University of Bari Aldo Moro in Bari, Italy, contributed to the paper.