Nanoscience and nanotechnology

Subterms

    More stories

    • 150 Shares189 Views

      in Energy

      Simple superconducting device could dramatically cut energy use in computing, other applications

      by

      MIT scientists and their colleagues have created a simple superconducting device that could transfer current through electronic devices much more efficiently than is possible today. As a result, the new diode, a kind of switch, could dramatically cut the amount of energy used in high-power computing systems, a major problem that is estimated to become much worse. Even though it is in the early stages of development, the diode is more than twice as efficient as similar ones reported by others. It could even be integral to emerging quantum computing technologies.

      The work, which is reported in the July 13 online issue of Physical Review Letters, is also the subject of a news story in Physics Magazine.

      “This paper showcases that the superconducting diode is an entirely solved problem from an engineering perspective,” says Philip Moll, director of the Max Planck Institute for the Structure and Dynamics of Matter in Germany. Moll was not involved in the work. “The beauty of [this] work is that [Moodera and colleagues] obtained record efficiencies without even trying [and] their structures are far from optimized yet.”

      “Our engineering of a superconducting diode effect that is robust and can operate over a wide temperature range in simple systems can potentially open the door for novel technologies,” says Jagadeesh Moodera, leader of the current work and a senior research scientist in MIT’s Department of Physics. Moodera is also affiliated with the Materials Research Laboratory, the Francis Bitter Magnet Laboratory, and the Plasma Science and Fusion Center (PSFC).

      The nanoscopic rectangular diode — about 1,000 times thinner than the diameter of a human hair — is easily scalable. Millions could be produced on a single silicon wafer.

      Toward a superconducting switch

      Diodes, devices that allow current to travel easily in one direction but not in the reverse, are ubiquitous in computing systems. Modern semiconductor computer chips contain billions of diode-like devices known as transistors. However, these devices can get very hot due to electrical resistance, requiring vast amounts of energy to cool the high-power systems in the data centers behind myriad modern technologies, including cloud computing. According to a 2018 news feature in Nature, these systems could use nearly 20 percent of the world’s power in 10 years.

      As a result, work toward creating diodes made of superconductors has been a hot topic in condensed matter physics. That’s because superconductors transmit current with no resistance at all below a certain low temperature (the critical temperature), and are therefore much more efficient than their semiconducting cousins, which have noticeable energy loss in the form of heat.

      Until now, however, other approaches to the problem have involved much more complicated physics. “The effect we found is due [in part] to a ubiquitous property of superconductors that can be realized in a very simple, straightforward manner. It just stares you in the face,” says Moodera.

      Says Moll of the Max Planck Institute, “The work is an important counterpoint to the current fashion to associate superconducting diodes [with] exotic physics, such as finite-momentum pairing states. While in reality, a superconducting diode is a common and widespread phenomenon present in classical materials, as a result of certain broken symmetries.”

      A somewhat serendipitous discovery

      In 2020 Moodera and colleagues observed evidence of an exotic particle pair known as Majorana fermions. These particle pairs could lead to a new family of topological qubits, the building blocks of quantum computers. While pondering approaches to creating superconducting diodes, the team realized that the material platform they developed for the Majorana work might also be applied to the diode problem.

      They were right. Using that general platform, they developed different iterations of superconducting diodes, each more efficient than the last. The first, for example, consisted of a nanoscopically thin layer of vanadium, a superconductor, which was patterned into a structure common to electronics (the Hall bar). When they applied a tiny magnetic field comparable to the Earth’s magnetic field, they saw the diode effect — a giant polarity dependence for current flow.

      They then created another diode, this time layering a superconductor with a ferromagnet (a ferromagnetic insulator in their case), a material that produces its own tiny magnetic field. After applying a tiny magnetic field to magnetize the ferromagnet so that it produces its own field, they found an even bigger diode effect that was stable even after the original magnetic field was turned off.

      Ubiquitous properties

      The team went on to figure out what was happening.

      In addition to transmitting current with no resistance, superconductors also have other, less well-known but just as ubiquitous properties. For example, they don’t like magnetic fields getting inside. When exposed to a tiny magnetic field, superconductors produce an internal supercurrent that induces its own magnetic flux that cancels the external field, thereby maintaining their superconducting state. This phenomenon, known as the Meissner screening effect, can be thought of as akin to our bodies’ immune system releasing antibodies to fight the infection of bacteria and other pathogens. This works, however, only up to some limit. Similarly, superconductors cannot entirely keep out large magnetic fields.

      The diodes the team created make use of this universal Meissner screening effect. The tiny magnetic field they applied — either directly, or through the adjacent ferromagnetic layer — activates the material’s screening current mechanism for expelling the external magnetic field and maintaining superconductivity.

      The team also found that another key factor in optimizing these superconductor diodes is tiny differences between the two sides, or edges, of the diode devices. These differences “create some sort of asymmetry in the way the magnetic field enters the superconductor,” Moodera says.

      By engineering their own form of edges on diodes to optimize these differences — for example, one edge with sawtooth features, while the other edge not intentionally altered — the team found that they could increase the efficiency from 20 percent to more than 50 percent. This discovery opens the door for devices whose edges could be “tuned” for even higher efficiencies, Moodera says.

      In sum, the team discovered that the edge asymmetries within superconducting diodes, the ubiquitous Meissner screening effect found in all superconductors, and a third property of superconductors known as vortex pinning all came together to produce the diode effect.

      “It is fascinating to see how inconspicuous yet ubiquitous factors can create a significant effect in observing the diode effect,” says Yasen Hou, first author of the paper and a postdoc at the Francis Bitter Magnet Laboratory and the PSFC. “What’s more exciting is that [this work] provides a straightforward approach with huge potential to further improve the efficiency.”

      Christoph Strunk is a professor at the University of Regensburg in Germany. Says Strunk, who was not involved in the research, “the present work demonstrates that the supercurrent in simple superconducting strips can become nonreciprocal. Moreover, when combined with a ferromagnetic insulator, the diode effect can even be maintained in the absence of an external magnetic field. The rectification direction can be programmed by the remnant magnetization of the magnetic layer, which may have high potential for future applications. The work is important and appealing both from the basic research and from the applications point of view.”

      Teenage contributors

      Moodera noted that the two researchers who created the engineered edges did so while still in high school during a summer at Moodera’s lab. They are Ourania Glezakou-Elbert of Richland, Washington, who will be going to Princeton University this fall, and Amith Varambally of Vestavia Hills, Alabama, who will be entering Caltech.

      Says Varambally, “I didn’t know what to expect when I set foot in Boston last summer, and certainly never expected to [be] a coauthor in a Physical Review Letters paper.

      “Every day was exciting, whether I was reading dozens of papers to better understand the diode phenomena, or operating machinery to fabricate new diodes for study, or engaging in conversations with Ourania, Dr. Hou, and Dr. Moodera about our research.

      “I am profoundly grateful to Dr. Moodera and Dr. Hou for providing me with the opportunity to work on such a fascinating project, and to Ourania for being a great research partner and friend.”

      In addition to Moodera and Hou, corresponding authors of the paper are professors Patrick A. Lee of the MIT Department of Physics and Akashdeep Kamra of Autonomous University of Madrid. Other authors from MIT are Liang Fu and Margarita Davydova of the Department of Physics, and Hang Chi, Alessandro Lodesani, and Yingying Wu, all of the Francis Bitter Magnet Laboratory and the Plasma Science and Fusion Center. Chi is also affiliated with the U.S. Army CCDC Research Laboratory.

      Authors also include Fabrizio Nichele, Markus F. Ritter, and Daniel Z. Haxwell of IBM Research Europe; Stefan Ilićof Materials Physics Center (CFM-MPC); and F. Sebastian Bergeret of CFM-MPC and Donostia International Physics Center.

      This work was supported by the Air Force Office of Sponsored Research, the Office of Naval Research, the National Science Foundation, and the Army Research Office. Additional funders are the European Research Council, the European Union’s Horizon 2020 Research and Innovation Framework Programme, the Spanish Ministry of Science and Innovation, the A. v. Humboldt Foundation, and the Department of Energy’s Office of Basic Sciences. More

    • 100 Shares189 Views

      in Energy

      Chemists discover why photosynthetic light-harvesting is so efficient

      by

      When photosynthetic cells absorb light from the sun, packets of energy called photons leap between a series of light-harvesting proteins until they reach the photosynthetic reaction center. There, cells convert the energy into electrons, which eventually power the production of sugar molecules.

      This transfer of energy through the light-harvesting complex occurs with extremely high efficiency: Nearly every photon of light absorbed generates an electron, a phenomenon known as near-unity quantum efficiency.

      A new study from MIT chemists offers a potential explanation for how proteins of the light-harvesting complex, also called the antenna, achieve that high efficiency. For the first time, the researchers were able to measure the energy transfer between light-harvesting proteins, allowing them to discover that the disorganized arrangement of these proteins boosts the efficiency of the energy transduction.

      “In order for that antenna to work, you need long-distance energy transduction. Our key finding is that the disordered organization of the light-harvesting proteins enhances the efficiency of that long-distance energy transduction,” says Gabriela Schlau-Cohen, an associate professor of chemistry at MIT and the senior author of the new study.

      MIT postdocs Dihao Wang and Dvir Harris and former MIT graduate student Olivia Fiebig PhD ’22 are the lead authors of the paper, which appears this week in the Proceedings of the National Academy of Sciences. Jianshu Cao, an MIT professor of chemistry, is also an author of the paper.

      Energy capture

      For this study, the MIT team focused on purple bacteria, which are often found in oxygen-poor aquatic environments and are commonly used as a model for studies of photosynthetic light-harvesting.

      Within these cells, captured photons travel through light-harvesting complexes consisting of proteins and light-absorbing pigments such as chlorophyll. Using ultrafast spectroscopy, a technique that uses extremely short laser pulses to study events that happen on timescales of femtoseconds to nanoseconds, scientists have been able to study how energy moves within a single one of these proteins. However, studying how energy travels between these proteins has proven much more challenging because it requires positioning multiple proteins in a controlled way.

      To create an experimental setup where they could measure how energy travels between two proteins, the MIT team designed synthetic nanoscale membranes with a composition similar to those of naturally occurring cell membranes. By controlling the size of these membranes, known as nanodiscs, they were able to control the distance between two proteins embedded within the discs.

      For this study, the researchers embedded two versions of the primary light-harvesting protein found in purple bacteria, known as LH2 and LH3, into their nanodiscs. LH2 is the protein that is present during normal light conditions, and LH3 is a variant that is usually expressed only during low light conditions.

      Using the cryo-electron microscope at the MIT.nano facility, the researchers could image their membrane-embedded proteins and show that they were positioned at distances similar to those seen in the native membrane. They were also able to measure the distances between the light-harvesting proteins, which were on the scale of 2.5 to 3 nanometers.

      Disordered is better

      Because LH2 and LH3 absorb slightly different wavelengths of light, it is possible to use ultrafast spectroscopy to observe the energy transfer between them. For proteins spaced closely together, the researchers found that it takes about 6 picoseconds for a photon of energy to travel between them. For proteins farther apart, the transfer takes up to 15 picoseconds.

      Faster travel translates to more efficient energy transfer, because the longer the journey takes, the more energy is lost during the transfer.

      “When a photon gets absorbed, you only have so long before that energy gets lost through unwanted processes such as nonradiative decay, so the faster it can get converted, the more efficient it will be,” Schlau-Cohen says.

      The researchers also found that proteins arranged in a lattice structure showed less efficient energy transfer than proteins that were arranged in randomly organized structures, as they usually are in living cells.

      “Ordered organization is actually less efficient than the disordered organization of biology, which we think is really interesting because biology tends to be disordered. This finding tells us that that may not just be an inevitable downside of biology, but organisms may have evolved to take advantage of it,” Schlau-Cohen says.

      Now that they have established the ability to measure inter-protein energy transfer, the researchers plan to explore energy transfer between other proteins, such as the transfer between proteins of the antenna to proteins of the reaction center. They also plan to study energy transfer between antenna proteins found in organisms other than purple bacteria, such as green plants.

      The research was funded primarily by the U.S. Department of Energy. More

    • 38 Shares159 Views

      in Energy

      Embracing life’s surprises

      by

      Experiments often yield unexpected results. In research and in life, MIT Associate Professor Cem Tasan has learned to embrace that uncertainty.

      “Very often we start with an idea or a hypothesis, and to test that idea we design experiments, and when we run the experiments, we see something totally different,” says Tasan, the newly tenured Thomas B. King Associate Professor of Metallurgy.

      Tasan has used those surprises to explore the boundaries of metallurgy and solid mechanics, gleaning new insights into how metals break and deform, and designing new kinds of damage-resistant alloys.

      “As they say, science is like taking a walk in the hills,” Tasan says. “You see the mountain far away, and that’s where you want to go, but as you head toward it, you see a beautiful flower on a different pathway, so you check that out. That happens so often to [my group]. It’s exciting.”

      Tasan has extended that approach to his career, leading him to take a faculty position at MIT despite not seeing the campus until his first job interview.

      “Being at MIT, or even in the USA, was never on my radar,” Tasan says. “It just wasn’t part of a plan.”

      That mindset has also helped him mentor students, whom he’s learned never to judge based on initial impressions.

      “I had a really bright student reach out and say ‘Everything is great, we have funding, we are productive, but I’m not sure I like what I’m doing,’” Tasan recalls. “We talked and identified another direction closer to the student’s interests, but that would mean we might not have secure funding or the necessary know-how, so there were all these disadvantages.

      “But we went down that road and it was amazing, because now this student was doing the research they really liked, and that successful student became an amazing student. Mentoring is complicated because on the outside things can seem fine, but the key idea is to pay attention to small details and keep communicating with these young people, who are on their own journeys. There’s no easy way other than communicating and observing.”

      A winding path

      Tasan grew up in Turkey and studied metallurgical and materials engineering at the country’s top college in the field, the Middle East Technical University.

      “What intrigued me about metallurgy is that it’s an engineering field, but it’s also strongly related with basic sciences,” Tasan says. “That connection exists in other engineering fields as well, but not as strongly. In materials science, it’s fair to say one leg is almost always in the fundamental side of things.”

      Tasan also travelled a lot as a young adult, backpacking with friends across Europe on a shoestring budget.

      “Early on, my personal goal in life was to move to Spain and eat tapas all the time and have fun,” Tasan jokes.

      During one such trip, Tasan packed a suit in the bottom of his backpack just in case he landed an interview with a graduate program. The preparation paid off in the Netherlands, where he met with members of the mechanical engineering department at the Eindhoven University of Technology. Tasan would go on to earn his PhD at the school, studying how damage and cracking takes place in metals.

      After earning his PhD in 2010, Tasan joined the Max Planck Institute for Iron Research in Germany, where he eventually led a research group that continued studying metal behavior and worked on creating new metal alloys that were more damage-resistant and had other unique properties.

      By 2015, Tasan was settled into a comfortable life in Germany. Then a position at MIT opened up.

      “At MIT, I could suddenly do much more on these topics that excited me, so my research could create a bigger impact,” Tasan says.

      After traveling to MIT for interviews, the talent and atmosphere also convinced Tasan to make the move.

      “I think it’s important to be surrounded by people who are very ambitious and who want to have a big impact,” Tasan says. “You walk in the Infinite Corridor, or any other MIT corridor, and every board you pass has stuff about people changing the world in a different way. Being in that environment inspires you.”

      Once in Cambridge, Tasan immediately loved what he describes as its “small-town feel,” comparing it to some European towns. He’s also embraced the Boston culture, becoming a fan of baseball and the Red Sox.

      Since arriving at MIT, Tasan’s group has studied metal samples’ response to stress and other stimuli in real time using a technique called in situ electron microscopy.

      “We do in situ tests, which means you take an electron microscope and basically build machines inside that allows you to take any metal and put it under different conditions, as you watch its structure evolve,” Tasan explains. “Because these experiments are so unique and complex, when a student designs an experiment and eventually brings the results back to me, it’s often the first-ever observation of some phenomena.”

      In 2020 Tasan’s group developed new in-situ methods for studying the effects of hydrogen in metals, leading to insights that could help with the transition to clean hydrogen energy. The approach has been adopted by other labs for further study.

      Tasan’s group also created a more damage resistant, high temperature alloy that’s part of a class of metals known as high entropy alloys. That work was published in the journal Nature Materials.

      “Doing physical metallurgy research allows us to connect basic understanding of metals and industrial applications,” Tasan says. “I’m dealing with atoms and how they interact — and at the same time I’m talking weekly with companies that produce thousands of tons of metals, and we’re using the same language. I can talk to a company producing steels for auto bodies or titanium for airplane engines, and the stuff I study in my lab is still valuable to them.”

      In one much-publicized Science paper, Tasan’s group uncovered the reasons why even the sharpest knives and razors dull after everyday processes like shaving.

      “We like to demonstrate the importance of materials science and metallurgy to a broader audience,” Tasan says. “The paper on why hair deforms steel was great because it was picked up in all kinds of news channels around the world, and it showed that even in very conventional areas, like making knives or blades, there’s a lot of new insights and paths to find.”

      Solving the ultimate puzzles

      Tasan brings the same careful diligence he uses to study metals to support students. He says he’s found that like metals, people also typically have more complex stories that you can only see if you look closely enough.

      “It’s interesting because everybody is so different,” Tasan says. “Once you start working with people and trying to help them, you see so many different dimensions that were not visible before. You have the opportunity to sit down with them and look them in the eye and try to understand what they really want. And it’s interesting because often they also don’t know what they want, and sometimes they even don’t know that they don’t know that!”

      Fortunately, Tasan enjoys those challenges most of all.

      “In a way, the researchers are puzzles waiting to be solved, like the research itself,” Tasan says. “And if you put in enough effort and you really care, you get this enormously gratifying feeling of helping someone succeed in life. It’s really a unique part of the job, and it’s what I love more than anything.” More

    • 100 Shares119 Views

      in Energy

      Paula Hammond wins faculty’s Killian Award for 2023-24

      by

      Paula Hammond, a leading innovator in nanotechnology and head of MIT’s Department of Chemical Engineering, has been named the recipient of the 2023-2024 James R. Killian Jr. Faculty Achievement Award.

      Hammond, an MIT Institute Professor, was honored for her work designing novel polymers and nanomaterials, which have extensive applications in fields including medicine and energy.

      “Professor Hammond is a pioneer in nanotechnology research, with a program that spans from basic science to translational research in medicine and energy. She has introduced new approaches for the design and development of complex drug delivery systems for cancer treatment and non-invasive imaging,” according to the award citation, which was read at the May 17 faculty meeting by Laura Kiessling, the chair of the Killian Award Selection Committee and the Novartis Professor of Chemistry at MIT.

      Established in 1971 to honor MIT’s 10th president, James Killian, the Killian Award recognizes extraordinary professional achievements by an MIT faculty member.

      “I’ve been to past Killian Award lectures, and I’ve always thought these were the ultimate achievers at MIT in terms of their work and their science,” Hammond says. “I am incredibly honored and overwhelmed to be considered even close to a part of that group.”

      Hammond, who earned her bachelor’s degree from MIT in 1984, worked as an engineer before returning to the Institute four years later to earn a PhD, which she received in 1993. After two years as a postdoc at Harvard University, she returned to MIT again as a faculty member in 1995.

      “In a world where it isn’t always cool to be heavy into your science and your work, MIT was a place where I felt like I could just be completely myself, and that was an amazing thing,” she says.

      Since joining the faculty, Hammond has pioneered techniques for creating thin polymer films and other materials using layer-by-layer assembly. This approach can be used to build polymers with highly controlled architectures by alternately exposing a surface to positively and negatively charged particles.

      Hammond’s lab uses this technique to design materials for many different applications, including drug delivery, regenerative medicine, noninvasive imaging, and battery technology.

      Her accomplishments include designing nanoparticles that can zoom in on tumors and release their cargo when they associate with cancer cells. She has also developed nanoparticles and thin polymer films that can carry multiple drugs to a specific site and release the drugs in a controlled or staggered fashion. In recent years, much of that work has focused on potential treatments and diagnostics for ovarian cancer.

      “We’ve really had a focus on ovarian cancer over the past several years. My hope is that our work will move us in the direction of understanding how we can treat ovarian cancer, and, in collaboration with my colleagues, how we can detect it more effectively,” says Hammond, who is a member of MIT’s Koch Institute for Integrative Cancer Research.

      The award committee also cited Hammond’s record of service, both to MIT and the national scientific community. She currently serves on the President’s Council of Advisors on Science and Technology, and she is a former member of the U.S. Secretary of Energy Scientific Advisory Board. At MIT, Hammond chaired the Initiative on Faculty Race and Diversity, and co-chaired the Academic and Professional Relationships Working Group and the Implementation Team of the MIT response to the National Academies’ report entitled “Sexual Harassment of Women.”

      Among her many honors, Hammond is one of only 25 scientists who have been elected to the National Academies of Engineering, Sciences, and Medicine.

      Hammond has also been recognized for her dedication to teaching and mentoring. As a reflection of her excellence in those areas, Hammond was awarded the Irwin Sizer Award for Significant Improvements to MIT Education, the Henry Hill Lecturer Award in 2002, and the Junior Bose Faculty Award in 2000. She also co-chaired the recent Ad Hoc Committee on Faculty Advising and Mentoring, and has been selected as a “Committed to Caring” honoree for her work mentoring students and postdocs in her research group.

      “The Selection Committee is delighted to have this opportunity to honor Professor Paula Hammond, not only for her tremendous professional achievements and contributions, but also for her genuine warmth and humanity, her thoughtfulness and effective leadership, and her empathy and ethics. She is someone worth emulating. Indeed, simply put, she is the best of us,” the award committee wrote in its citation. More

    • 75 Shares129 Views

      in Environment

      J-WAFS announces 2023 seed grant recipients

      by

      Today, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) announced its ninth round of seed grants to support innovative research projects at MIT. The grants are designed to fund research efforts that tackle challenges related to water and food for human use, with the ultimate goal of creating meaningful impact as the world population continues to grow and the planet undergoes significant climate and environmental changes.Ten new projects led by 15 researchers from seven different departments will be supported this year. The projects address a range of challenges by employing advanced materials, technology innovations, and new approaches to resource management. The new projects aim to remove harmful chemicals from water sources, develop monitoring and other systems to help manage various aquaculture industries, optimize water purification materials, and more.“The seed grant program is J-WAFS’ flagship grant initiative,” says J-WAFS executive director Renee J. Robins. “The funding is intended to spur groundbreaking MIT research addressing complex issues that are challenging our water and food systems. The 10 projects selected this year show great promise, and we look forward to the progress and accomplishments these talented researchers will make,” she adds.The 2023 J-WAFS seed grant researchers and their projects are:Sara Beery, an assistant professor in the Department of Electrical Engineering and Computer Science (EECS), is building the first completely automated system to estimate the size of salmon populations in the Pacific Northwest (PNW).Salmon are a keystone species in the PNW, feeding human populations for the last 7,500 years at least. However, overfishing, habitat loss, and climate change threaten extinction of salmon populations across the region. Accurate salmon counts during their seasonal migration to their natal river to spawn are essential for fisheries’ regulation and management but are limited by human capacity. Fish population monitoring is a widespread challenge in the United States and worldwide. Beery and her team are working to build a system that will provide a detailed picture of the state of salmon populations in unprecedented, spatial, and temporal resolution by combining sonar sensors and computer vision and machine learning (CVML) techniques. The sonar will capture individual fish as they swim upstream and CVML will train accurate algorithms to interpret the sonar video for detecting, tracking, and counting fish automatically while adapting to changing river conditions and fish densities.Another aquaculture project is being led by Michael Triantafyllou, the Henry L. and Grace Doherty Professor in Ocean Science and Engineering in the Department of Mechanical Engineering, and Robert Vincent, the assistant director at MIT’s Sea Grant Program. They are working with Otto Cordero, an associate professor in the Department of Civil and Environmental Engineering, to control harmful bacteria blooms in aquaculture algae feed production.

      Aquaculture in the United States represents a $1.5 billion industry annually and helps support 1.7 million jobs, yet many American hatcheries are not able to keep up with demand. One barrier to aquaculture production is the high degree of variability in survival rates, most likely caused by a poorly controlled microbiome that leads to bacterial infections and sub-optimal feed efficiency. Triantafyllou, Vincent, and Cordero plan to monitor the microbiome composition of a shellfish hatchery in order to identify possible causing agents of mortality, as well as beneficial microbes. They hope to pair microbe data with detail phenotypic information about the animal population to generate rapid diagnostic tests and explore the potential for microbiome therapies to protect larvae and prevent future outbreaks. The researchers plan to transfer their findings and technology to the local and regional aquaculture community to ensure healthy aquaculture production that will support the expansion of the U.S. aquaculture industry.

      David Des Marais is the Cecil and Ida Green Career Development Professor in the Department of Civil and Environmental Engineering. His 2023 J-WAFS project seeks to understand plant growth responses to elevated carbon dioxide (CO2) in the atmosphere, in the hopes of identifying breeding strategies that maximize crop yield under future CO2 scenarios.Today’s crop plants experience higher atmospheric CO2 than 20 or 30 years ago. Crops such as wheat, oat, barley, and rice typically increase their growth rate and biomass when grown at experimentally elevated atmospheric CO2. This is known as the so-called “CO2 fertilization effect.” However, not all plant species respond to rising atmospheric CO2 with increased growth, and for the ones that do, increased growth doesn’t necessarily correspond to increased crop yield. Using specially built plant growth chambers that can control the concentration of CO2, Des Marais will explore how CO2 availability impacts the development of tillers (branches) in the grass species Brachypodium. He will study how gene expression controls tiller development, and whether this is affected by the growing environment. The tillering response refers to how many branches a plant produces, which sets a limit on how much grain it can yield. Therefore, optimizing the tillering response to elevated CO2 could greatly increase yield. Des Marais will also look at the complete genome sequence of Brachypodium, wheat, oat, and barley to help identify genes relevant for branch growth.Darcy McRose, an assistant professor in the Department of Civil and Environmental Engineering, is researching whether a combination of plant metabolites and soil bacteria can be used to make mineral-associated phosphorus more bioavailable.The nutrient phosphorus is essential for agricultural plant growth, but when added as a fertilizer, phosphorus sticks to the surface of soil minerals, decreasing bioavailability, limiting plant growth, and accumulating residual phosphorus. Heavily fertilized agricultural soils often harbor large reservoirs of this type of mineral-associated “legacy” phosphorus. Redox transformations are one chemical process that can liberate mineral-associated phosphorus. However, this needs to be carefully controlled, as overly mobile phosphorus can lead to runoff and pollution of natural waters. Ideally, phosphorus would be made bioavailable when plants need it and immobile when they don’t. Many plants make small metabolites called coumarins that might be able to solubilize mineral-adsorbed phosphorus and be activated and inactivated under different conditions. McRose will use laboratory experiments to determine whether a combination of plant metabolites and soil bacteria can be used as a highly efficient and tunable system for phosphorus solubilization. She also aims to develop an imaging platform to investigate exchanges of phosphorus between plants and soil microbes.Many of the 2023 seed grants will support innovative technologies to monitor, quantify, and remediate various kinds of pollutants found in water. Two of the new projects address the problem of per- and polyfluoroalkyl substances (PFAS), human-made chemicals that have recently emerged as a global health threat. Known as “forever chemicals,” PFAS are used in many manufacturing processes. These chemicals are known to cause significant health issues including cancer, and they have become pervasive in soil, dust, air, groundwater, and drinking water. Unfortunately, the physical and chemical properties of PFAS render them difficult to detect and remove.Aristide Gumyusenge, the Merton C. Assistant Professor of Materials Science and Engineering, is using metal-organic frameworks for low-cost sensing and capture of PFAS. Most metal-organic frameworks (MOFs) are synthesized as particles, which complicates their high accuracy sensing performance due to defects such as intergranular boundaries. Thin, film-based electronic devices could enable the use of MOFs for many applications, especially chemical sensing. Gumyusenge’s project aims to design test kits based on two-dimensional conductive MOF films for detecting PFAS in drinking water. In early demonstrations, Gumyusenge and his team showed that these MOF films can sense PFAS at low concentrations. They will continue to iterate using a computation-guided approach to tune sensitivity and selectivity of the kits with the goal of deploying them in real-world scenarios.Carlos Portela, the Brit (1961) and Alex (1949) d’Arbeloff Career Development Professor in the Department of Mechanical Engineering, and Ariel Furst, the Cook Career Development Professor in the Department of Chemical Engineering, are building novel architected materials to act as filters for the removal of PFAS from water. Portela and Furst will design and fabricate nanoscale materials that use activated carbon and porous polymers to create a physical adsorption system. They will engineer the materials to have tunable porosities and morphologies that can maximize interactions between contaminated water and functionalized surfaces, while providing a mechanically robust system.Rohit Karnik is a Tata Professor and interim co-department head of the Department of Mechanical Engineering. He is working on another technology, his based on microbead sensors, to rapidly measure and monitor trace contaminants in water.Water pollution from both biological and chemical contaminants contributes to an estimated 1.36 million deaths annually. Chemical contaminants include pesticides and herbicides, heavy metals like lead, and compounds used in manufacturing. These emerging contaminants can be found throughout the environment, including in water supplies. The Environmental Protection Agency (EPA) in the United States sets recommended water quality standards, but states are responsible for developing their own monitoring criteria and systems, which must be approved by the EPA every three years. However, the availability of data on regulated chemicals and on candidate pollutants is limited by current testing methods that are either insensitive or expensive and laboratory-based, requiring trained scientists and technicians. Karnik’s project proposes a simple, self-contained, portable system for monitoring trace and emerging pollutants in water, making it suitable for field studies. The concept is based on multiplexed microbead-based sensors that use thermal or gravitational actuation to generate a signal. His proposed sandwich assay, a testing format that is appealing for environmental sensing, will enable both single-use and continuous monitoring. The hope is that the bead-based assays will increase the ease and reach of detecting and quantifying trace contaminants in water for both personal and industrial scale applications.Alexander Radosevich, a professor in the Department of Chemistry, and Timothy Swager, the John D. MacArthur Professor of Chemistry, are teaming up to create rapid, cost-effective, and reliable techniques for on-site arsenic detection in water.Arsenic contamination of groundwater is a problem that affects as many as 500 million people worldwide. Arsenic poisoning can lead to a range of severe health problems from cancer to cardiovascular and neurological impacts. Both the EPA and the World Health Organization have established that 10 parts per billion is a practical threshold for arsenic in drinking water, but measuring arsenic in water at such low levels is challenging, especially in resource-limited environments where access to sensitive laboratory equipment may not be readily accessible. Radosevich and Swager plan to develop reaction-based chemical sensors that bind and extract electrons from aqueous arsenic. In this way, they will exploit the inherent reactivity of aqueous arsenic to selectively detect and quantify it. This work will establish the chemical basis for a new method of detecting trace arsenic in drinking water.Rajeev Ram is a professor in the Department of Electrical Engineering and Computer Science. His J-WAFS research will advance a robust technology for monitoring nitrogen-containing pollutants, which threaten over 15,000 bodies of water in the United States alone.Nitrogen in the form of nitrate, nitrite, ammonia, and urea can run off from agricultural fertilizer and lead to harmful algal blooms that jeopardize human health. Unfortunately, monitoring these contaminants in the environment is challenging, as sensors are difficult to maintain and expensive to deploy. Ram and his students will work to establish limits of detection for nitrate, nitrite, ammonia, and urea in environmental, industrial, and agricultural samples using swept-source Raman spectroscopy. Swept-source Raman spectroscopy is a method of detecting the presence of a chemical by using a tunable, single mode laser that illuminates a sample. This method does not require costly, high-power lasers or a spectrometer. Ram will then develop and demonstrate a portable system that is capable of achieving chemical specificity in complex, natural environments. Data generated by such a system should help regulate polluters and guide remediation.Kripa Varanasi, a professor in the Department of Mechanical Engineering, and Angela Belcher, the James Mason Crafts Professor and head of the Department of Biological Engineering, will join forces to develop an affordable water disinfection technology that selectively identifies, adsorbs, and kills “superbugs” in domestic and industrial wastewater.Recent research predicts that antibiotic-resistance bacteria (superbugs) will result in $100 trillion in health care expenses and 10 million deaths annually by 2050. The prevalence of superbugs in our water systems has increased due to corroded pipes, contamination, and climate change. Current drinking water disinfection technologies are designed to kill all types of bacteria before human consumption. However, for certain domestic and industrial applications there is a need to protect the good bacteria required for ecological processes that contribute to soil and plant health. Varanasi and Belcher will combine material, biological, process, and system engineering principles to design a sponge-based water disinfection technology that can identify and destroy harmful bacteria while leaving the good bacteria unharmed. By modifying the sponge surface with specialized nanomaterials, their approach will be able to kill superbugs faster and more efficiently. The sponge filters can be deployed under very low pressure, making them an affordable technology, especially in resource-constrained communities.In addition to the 10 seed grant projects, J-WAFS will also fund a research initiative led by Greg Sixt. Sixt is the research manager for climate and food systems at J-WAFS, and the director of the J-WAFS-led Food and Climate Systems Transformation (FACT) Alliance. His project focuses on the Lake Victoria Basin (LVB) of East Africa. The second-largest freshwater lake in the world, Lake Victoria straddles three countries (Uganda, Tanzania, and Kenya) and has a catchment area that encompasses two more (Rwanda and Burundi). Sixt will collaborate with Michael Hauser of the University of Natural Resources and Life Sciences, Vienna, and Paul Kariuki, of the Lake Victoria Basin Commission.The group will study how to adapt food systems to climate change in the Lake Victoria Basin. The basin is facing a range of climate threats that could significantly impact livelihoods and food systems in the expansive region. For example, extreme weather events like droughts and floods are negatively affecting agricultural production and freshwater resources. Across the LVB, current approaches to land and water management are unsustainable and threaten future food and water security. The Lake Victoria Basin Commission (LVBC), a specialized institution of the East African Community, wants to play a more vital role in coordinating transboundary land and water management to support transitions toward more resilient, sustainable, and equitable food systems. The primary goal of this research will be to support the LVBC’s transboundary land and water management efforts, specifically as they relate to sustainability and climate change adaptation in food systems. The research team will work with key stakeholders in Kenya, Uganda, and Tanzania to identify specific capacity needs to facilitate land and water management transitions. The two-year project will produce actionable recommendations to the LVBC. More

    • 125 Shares199 Views

      in Environment

      Four researchers with MIT ties earn 2023 Schmidt Science Fellowships

      by

      Four researchers with ties to MIT have been named Schmidt Science Fellows this year. Lillian Chin ’17, SM ’19; Neil Dalvie PD ’22, PhD ’22; Suong Nguyen, and Yirui Zhang SM ’19, PhD ’23 are among the 32 exceptional early-career scientists worldwide chosen to receive the prestigious fellowships.

      “History provides powerful examples of what happens when scientists are given the freedom to ask big questions which can achieve real breakthroughs across disciplines,” says Wendy Schmidt, co-founder of Schmidt Futures and president of the Schmidt Family Foundation. “Schmidt Science Fellows are tackling climate destruction, discovering new drugs against disease, developing novel materials, using machine learning to understand the drivers of human health, and much more. This new cohort will add to this legacy in applying scientific discovery to improve human health and opportunity, and preserve and restore essential planetary systems.”

      Schmidt Futures is a philanthropic initiative that brings talented people together in networks to prove out their ideas and solve hard problems in science and society. Schmidt Science Fellows receive a stipend of $100,000 a year for up to two years of postdoctoral research in a discipline different from their PhD at a world-leading lab anywhere across the globe.

      Lillian Chin ’17, SM ’19 is currently pursuing her PhD in the Department of Electrical Engineering and Computer Science. Her research focuses on creating new materials for robots. By designing the geometry of a material, Chin creates new “meta-materials” that have different properties from the original. Using this technique, she has created robot balls that dramatically expand in volume and soft grippers that can work in dangerous environments. All of these robots are built out of a single material, letting the researchers 3D print them with extra internal features like channels. These channels help to measure the deformation of metamaterials, enabling Chin and her collaborators to create robots that are strong, can move, and sense their own shape, like muscles do.

      “I feel very honored to have been chosen for this fellowship,” says Chin. “I feel like I proposed a very risky pivot, since my background is only in engineering, with very limited exposure to neuroscience. I’m very excited to be given the opportunity to learn best practices for interacting with patients and be able to translate my knowledge from robotics to biology.”

      With the Schmidt Fellowship, Chin plans to pursue new frontiers for custom materials with internal sensors, which can measure force and deformation and can be placed anywhere within the material. “I want to use these materials to make tools for clinicians and neuroscientists to better understand how humans touch and grasp objects around them,” says Chin. “I’m especially interested in seeing how my materials could help in diagnosis motor-related diseases or improve rehab outcomes by providing the patient with feedback. This will help me create robots that have a better sense of touch and learn how to move objects around like humans do.”

      Neil Dalvie PD ’22, PhD ’22 is a graduate of the Department of Chemical Engineering, where he worked with Professor J. Christopher Love on manufacturing of therapeutic proteins. Dalvie developed molecular biology techniques for manufacturing high-quality proteins in yeast, which enables rapid testing of new products and low-cost manufacturing and large scales. During the pandemic, he led a team that applied these learnings to develop a Covid-19 vaccine that was deployed in multiple low-income countries. After graduating, Dalvie wanted to apply the precision biological engineering that is routinely deployed in medicinal manufacturing to other large-scale bioprocesses.

      “It’s rare for scientists to cross large technical gaps after so many years of specific training to get a PhD — you get comfy being an expert in your field,” says Dalvie. “I was definitely intimidated by the giant leap from vaccine manufacturing to the natural rock cycle. The fellowship has allowed me to dive into the new field by removing immediate pressure to publish or find my next job. I am excited for what commonalities we will find between biomanufacturing and biogeochemistry.”

      As a Schmidt Science Fellow, Dalvie will work with Professor Pamela Silver at Harvard Medical School on engineering microorganisms for enhanced rock weathering and carbon sequestration to combat climate change. They are applying modern molecular biology to enhance natural biogeochemical processes at gigaton scales.

      Suong (Su) Nguyen, a postdoctoral researcher in Professor Jeremiah Johnson’s lab in the Department of Chemistry, earned her PhD from Princeton University, where she developed light-driven, catalytic methodologies for organic synthesis, biomass valorization, plastic waste recycling, and functionalization of quantum sensing materials.

      As a Schmidt Science fellow, Nguyen will pivot from organic chemistry to nanomaterials. Biological systems are able to synthesize macromolecules with precise structure essential for their biological function. Scientists have long dreamed of achieving similar control over synthetic materials, but existing methods are inefficient and limited in scope. Nguyen hopes to develop new strategies to achieve such high level of control over the structure and properties of nanomaterials and explore their potential for use in therapeutic applications.

      “I feel extremely honored and grateful to receive the Schmidt Science Fellowship,” says Nguyen. “The fellowship will provide me with a unique opportunity to engage with scientists from a very wide range of research backgrounds. I believe this will significantly shape the research objectives for my future career.”

      Yirui Zhang SM ’19, PhD ’22 is a graduate of the Department of Mechanical Engineering. Zhang’s research focuses on electrochemical energy storage and conversion, including lithium-ion batteries and electrocatalysis. She has developed in situ spectroscopy and electrochemical methods to probe the electrode-electrolyte interface, understand the interfacial molecular structures, and unravel the fundamental thermodynamics and kinetics of (electro)chemical reactions in energy storage. Further, she has leveraged the physical chemistry of liquids and tuned the molecular structures at the interface to improve the stability and kinetics of electrochemical reactions. 

      “I am honored and thrilled to have been named a Schmidt Science Fellow,” says Zhang. “The fellowship will not only provide me with the unique opportunity to broaden my scientific perspectives and pursue pivoting research, but also create a lifelong network for us to collaborate across diverse fields and become scientific and societal thought leaders. I look forward to pushing the boundaries of my research and advancing technologies to tackle global challenges in energy storage and health care with interdisciplinary efforts!”

      As a Schmidt Science Fellow, Zhang will work across disciplines and pivot to biosensing. She plans to combine spectroscopy, electrokinetics, and machine learning to develop a fast and cost-effective technique for monitoring and understanding infectious disease. The innovations will benefit next-generation point-of-care medical devices and wastewater-based epidemiology to provide timely diagnosis and help protect humans against deadly infections and antimicrobial resistance. More

    • 125 Shares99 Views

      in Energy

      Moving perovskite advancements from the lab to the manufacturing floor

      by

      The following was issued as a joint announcement from MIT.nano and the MIT Research Laboratory for Electronics; CubicPV; Verde Technologies; Princeton University; and the University of California at San Diego.

      Tandem solar cells are made of stacked materials — such as silicon paired with perovskites — that together absorb more of the solar spectrum than single materials, resulting in a dramatic increase in efficiency. Their potential to generate significantly more power than conventional cells could make a meaningful difference in the race to combat climate change and the transition to a clean-energy future.

      However, current methods to create stable and efficient perovskite layers require time-consuming, painstaking rounds of design iteration and testing, inhibiting their development for commercial use. Today, the U.S. Department of Energy Solar Energy Technologies Office (SETO) announced that MIT has been selected to receive an $11.25 million cost-shared award to establish a new research center to address this challenge by using a co-optimization framework guided by machine learning and automation.

      A collaborative effort with lead industry participant CubicPV, solar startup Verde Technologies, and academic partners Princeton University and the University of California San Diego (UC San Diego), the center will bring together teams of researchers to support the creation of perovskite-silicon tandem solar modules that are co-designed for both stability and performance, with goals to significantly accelerate R&D and the transfer of these achievements into commercial environments.

      “Urgent challenges demand rapid action. This center will accelerate the development of tandem solar modules by bringing academia and industry into closer partnership,” says MIT professor of mechanical engineering Tonio Buonassisi, who will direct the center. “We’re grateful to the Department of Energy for supporting this powerful new model and excited to get to work.”

      Adam Lorenz, CTO of solar energy technology company CubicPV, stresses the importance of thinking about scale, alongside quality and efficiency, to accelerate the perovskite effort into the commercial environment. “Instead of chasing record efficiencies with tiny pixel-sized devices and later attempting to stabilize them, we will simultaneously target stability, reproducibility, and efficiency,” he says. “It’s a module-centric approach that creates a direct channel for R&D advancements into industry.”

      The center will be named Accelerated Co-Design of Durable, Reproducible, and Efficient Perovskite Tandems, or ADDEPT. The grant will be administered through the MIT Research Laboratory for Electronics (RLE).

      David Fenning, associate professor of nanoengineering at UC San Diego, has worked with Buonassisi on the idea of merging materials, automation, and computation, specifically in this field of artificial intelligence and solar, since 2014. Now, a central thrust of the ADDEPT project will be to deploy machine learning and robotic screening to optimize processing of perovskite-based solar materials for efficiency and durability.

      “We have already seen early indications of successful technology transfer between our UC San Diego robot PASCAL and industry,” says Fenning. “With this new center, we will bring research labs and the emerging perovskite industry together to improve reproducibility and reduce time to market.”

      “Our generation has an obligation to work collaboratively in the fight against climate change,” says Skylar Bagdon, CEO of Verde Technologies, which received the American-Made Perovskite Startup Prize. “Throughout the course of this center, Verde will do everything in our power to help this brilliant team transition lab-scale breakthroughs into the world where they can have an impact.”

      Several of the academic partners echoed the importance of the joint effort between academia and industry. Barry Rand, professor of electrical and computer engineering at the Andlinger Center for Energy and the Environment at Princeton University, pointed to the intersection of scientific knowledge and market awareness. “Understanding how chemistry affects films and interfaces will empower us to co-design for stability and performance,” he says. “The center will accelerate this use-inspired science, with close guidance from our end customers, the industry partners.”

      A critical resource for the center will be MIT.nano, a 200,000-square-foot research facility set in the heart of the campus. MIT.nano Director Vladimir Bulović, the Fariborz Maseeh (1990) Professor of Emerging Technology, says he envisions MIT.nano as a hub for industry and academic partners, facilitating technology development and transfer through shared lab space, open-access equipment, and streamlined intellectual property frameworks.

      “MIT has a history of groundbreaking innovation using perovskite materials for solar applications,” says Bulović. “We’re thrilled to help build on that history by anchoring ADDEPT at MIT.nano and working to help the nation advance the future of these promising materials.”

      MIT was selected as a part of the SETO Fiscal Year 2022 Photovoltaics (PV) funding program, an effort to reduce costs and supply chain vulnerabilities, further develop durable and recyclable solar technologies, and advance perovskite PV technologies toward commercialization. ADDEPT is one project that will tackle perovskite durability, which will extend module life. The overarching goal of these projects is to lower the levelized cost of electricity generated by PV.

      Research groups involved with the ADDEPT project at MIT include Buonassisi’s Accelerated Materials Laboratory for Sustainability (AMLS), Bulović’s Organic and Nanostructured Electronics (ONE) Lab, and the Bawendi Group led by Lester Wolfe Professor in Chemistry Moungi Bawendi. Also working on the project is Jeremiah Mwaura, research scientist in the ONE Lab. More

    • 150 Shares159 Views

      in Energy

      MIT engineers devise technology to prevent fouling in photobioreactors for CO2 capture

      by

      Algae grown in transparent tanks or tubes supplied with carbon dioxide can convert the greenhouse gas into other compounds, such as food supplements or fuels. But the process leads to a buildup of algae on the surfaces that clouds them and reduces efficiency, requiring laborious cleanout procedures every couple of weeks.

      MIT researchers have come up with a simple and inexpensive technology that could substantially limit this fouling, potentially allowing for a much more efficient and economical way of converting the unwanted greenhouse gas into useful products.

      The key is to coat the transparent containers with a material that can hold an electrostatic charge, and then applying a very small voltage to that layer. The system has worked well in lab-scale tests, and with further development might be applied to commercial production within a few years.

      The findings are being reported in the journal Advanced Functional Materials, in a paper by recent MIT graduate Victor Leon PhD ’23, professor of mechanical engineering Kripa Varanasi, former postdoc Baptiste Blanc, and undergraduate student Sophia Sonnert.

      No matter how successful efforts to reduce or eliminate carbon emissions may be, there will still be excess greenhouse gases that will remain in the atmosphere for centuries to come, continuing to affect global climate, Varanasi points out. “There’s already a lot of carbon dioxide there, so we have to look at negative emissions technologies as well,” he says, referring to ways of removing the greenhouse gas from the air or oceans, or from their sources before they get released into the air in the first place.

      When people think of biological approaches to carbon dioxide reduction, the first thought is usually of planting or protecting trees, which are indeed a crucial “sink” for atmospheric carbon. But there are others. “Marine algae account for about 50 percent of global carbon dioxide absorbed today on Earth,” Varanasi says. These algae grow anywhere from 10 to 50 times more quickly than land-based plants, and they can be grown in ponds or tanks that take up only a tenth of the land footprint of terrestrial plants.

      What’s more, the algae themselves can then be a useful product. “These algae are rich in proteins, vitamins and other nutrients,” Varanasi says, noting they could produce far more nutritional output per unit of land used than some traditional agricultural crops.

      If attached to the flue gas output of a coal or gas power plant, algae could not only thrive on the carbon dioxide as a nutrient source, but some of the microalgae species could also consume the associated nitrogen and sulfur oxides present in these emissions. “For every two or three kilograms of CO2, a kilogram of algae could be produced, and these could be used as biofuels, or for Omega-3, or food,” Varanasi says.

      Omega-3 fatty acids are a widely used food supplement, as they are an essential part of cell membranes and other tissues but cannot be made by the body and must be obtained from food. “Omega 3 is particularly attractive because it’s also a much higher-value product,” Varanasi says.

      Most algae grown commercially are cultivated in shallow ponds, while others are grown in transparent tubes called photobioreactors. The tubes can produce seven to 10 times greater yields than ponds for a given amount of land, but they face a major problem: The algae tend to build up on the transparent surfaces, requiring frequent shutdowns of the whole production system for cleaning, which can take as long as the productive part of the cycle, thus cutting overall output in half and adding to operational costs.

      The fouling also limits the design of the system. The tubes can’t be too small because the fouling would begin to block the flow of water through the bioreactor and require higher pumping rates.

      Varanasi and his team decided to try to use a natural characteristic of the algae cells to defend against fouling. Because the cells naturally carry a small negative electric charge on their membrane surface, the team figured that electrostatic repulsion could be used to push them away.

      The idea was to create a negative charge on the vessel walls, such that the electric field forces the algae cells away from the walls. To create such an electric field requires a high-performance dielectric material, which is an electrical insulator with a high “permittivity” that can produce a large change in surface charge with a smaller voltage.

      “What people have done before with applying voltage [to bioreactors] has been with conductive surfaces,” Leon explains, “but what we’re doing here is specifically with nonconductive surfaces.”

      He adds: “If it’s conductive, then you pass current and you’re kind of shocking the cells. What we’re trying to do is pure electrostatic repulsion, so the surface would be negative and the cell is negative so you get repulsion. Another way to describe it is like a force field, whereas before the cells were touching the surface and getting shocked.”

      The team worked with two different dielectric materials, silicon dioxide — essentially glass — and hafnia (hafnium oxide), both of which turned out to be far more efficient at minimizing fouling than conventional plastics used to make photobioreactors. The material can be applied in a coating that is vanishingly thin, just 10 to 20 nanometers (billionths of a meter) thick, so very little would be needed to coat a full photobioreactor system.

      “What we are excited about here is that we are able to show that purely from electrostatic interactions, we are able to control cell adhesion,” Varanasi says. “It’s almost like an on-off switch, to be able to do this.”

      Additionally, Leon says, “Since we’re using this electrostatic force, we don’t really expect it to be cell-specific, and we think there’s potential for applying it with other cells than just algae. In future work, we’d like to try using it with mammalian cells, bacteria, yeast, and so on.” It could also be used with other valuable types of algae, such as spirulina, that are widely used as food supplements.

      The same system could be used to either repel or attract cells by just reversing the voltage, depending on the particular application. Instead of algae, a similar setup might be used with human cells to produce artificial organs by producing a scaffold that could be charged to attract the cells into the right configuration, Varanasi suggests.

      “Our study basically solves this major problem of biofouling, which has been a bottleneck for photobioreactors,” he says. “With this technology, we can now really achieve the full potential” of such systems, although further development will be needed to scale up to practical, commercial systems.

      As for how soon this could be ready for widespread deployment, he says, “I don’t see why not in three years’ timeframe, if we get the right resources to be able to take this work forward.”

      The study was supported by energy company Eni S.p.A., through the MIT Energy Initiative. More