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    Nanoscale transistors could enable more efficient electronics

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    Silicon transistors, which are used to amplify and switch signals, are a critical component in most electronic devices, from smartphones to automobiles. But silicon semiconductor technology is held back by a fundamental physical limit that prevents transistors from operating below a certain voltage.This limit, known as “Boltzmann tyranny,” hinders the energy efficiency of computers and other electronics, especially with the rapid development of artificial intelligence technologies that demand faster computation.In an effort to overcome this fundamental limit of silicon, MIT researchers fabricated a different type of three-dimensional transistor using a unique set of ultrathin semiconductor materials.Their devices, featuring vertical nanowires only a few nanometers wide, can deliver performance comparable to state-of-the-art silicon transistors while operating efficiently at much lower voltages than conventional devices.“This is a technology with the potential to replace silicon, so you could use it with all the functions that silicon currently has, but with much better energy efficiency,” says Yanjie Shao, an MIT postdoc and lead author of a paper on the new transistors.The transistors leverage quantum mechanical properties to simultaneously achieve low-voltage operation and high performance within an area of just a few square nanometers. Their extremely small size would enable more of these 3D transistors to be packed onto a computer chip, resulting in fast, powerful electronics that are also more energy-efficient.“With conventional physics, there is only so far you can go. The work of Yanjie shows that we can do better than that, but we have to use different physics. There are many challenges yet to be overcome for this approach to be commercial in the future, but conceptually, it really is a breakthrough,” says senior author Jesús del Alamo, the Donner Professor of Engineering in the MIT Department of Electrical Engineering and Computer Science (EECS).They are joined on the paper by Ju Li, the Tokyo Electric Power Company Professor in Nuclear Engineering and professor of materials science and engineering at MIT; EECS graduate student Hao Tang; MIT postdoc Baoming Wang; and professors Marco Pala and David Esseni of the University of Udine in Italy. The research appears today in Nature Electronics.Surpassing siliconIn electronic devices, silicon transistors often operate as switches. Applying a voltage to the transistor causes electrons to move over an energy barrier from one side to the other, switching the transistor from “off” to “on.” By switching, transistors represent binary digits to perform computation.A transistor’s switching slope reflects the sharpness of the “off” to “on” transition. The steeper the slope, the less voltage is needed to turn on the transistor and the greater its energy efficiency.But because of how electrons move across an energy barrier, Boltzmann tyranny requires a certain minimum voltage to switch the transistor at room temperature.To overcome the physical limit of silicon, the MIT researchers used a different set of semiconductor materials — gallium antimonide and indium arsenide — and designed their devices to leverage a unique phenomenon in quantum mechanics called quantum tunneling.Quantum tunneling is the ability of electrons to penetrate barriers. The researchers fabricated tunneling transistors, which leverage this property to encourage electrons to push through the energy barrier rather than going over it.“Now, you can turn the device on and off very easily,” Shao says.But while tunneling transistors can enable sharp switching slopes, they typically operate with low current, which hampers the performance of an electronic device. Higher current is necessary to create powerful transistor switches for demanding applications.Fine-grained fabricationUsing tools at MIT.nano, MIT’s state-of-the-art facility for nanoscale research, the engineers were able to carefully control the 3D geometry of their transistors, creating vertical nanowire heterostructures with a diameter of only 6 nanometers. They believe these are the smallest 3D transistors reported to date.Such precise engineering enabled them to achieve a sharp switching slope and high current simultaneously. This is possible because of a phenomenon called quantum confinement.Quantum confinement occurs when an electron is confined to a space that is so small that it can’t move around. When this happens, the effective mass of the electron and the properties of the material change, enabling stronger tunneling of the electron through a barrier.Because the transistors are so small, the researchers can engineer a very strong quantum confinement effect while also fabricating an extremely thin barrier.“We have a lot of flexibility to design these material heterostructures so we can achieve a very thin tunneling barrier, which enables us to get very high current,” Shao says.Precisely fabricating devices that were small enough to accomplish this was a major challenge.“We are really into single-nanometer dimensions with this work. Very few groups in the world can make good transistors in that range. Yanjie is extraordinarily capable to craft such well-functioning transistors that are so extremely small,” says del Alamo.When the researchers tested their devices, the sharpness of the switching slope was below the fundamental limit that can be achieved with conventional silicon transistors. Their devices also performed about 20 times better than similar tunneling transistors.“This is the first time we have been able to achieve such sharp switching steepness with this design,” Shao adds.The researchers are now striving to enhance their fabrication methods to make transistors more uniform across an entire chip. With such small devices, even a 1-nanometer variance can change the behavior of the electrons and affect device operation. They are also exploring vertical fin-shaped structures, in addition to vertical nanowire transistors, which could potentially improve the uniformity of devices on a chip.“This work definitively steps in the right direction, significantly improving the broken-gap tunnel field effect transistor (TFET) performance. It demonstrates steep-slope together with a record drive-current. It highlights the importance of small dimensions, extreme confinement, and low-defectivity materials and interfaces in the fabricated broken-gap TFET. These features have been realized through a well-mastered and nanometer-size-controlled process,” says Aryan Afzalian, a principal member of the technical staff at the nanoelectronics research organization imec, who was not involved with this work.This research is funded, in part, by Intel Corporation. More

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      Affordable high-tech windows for comfort and energy savings

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      Imagine if the windows of your home didn’t transmit heat. They’d keep the heat indoors in winter and outdoors on a hot summer’s day. Your heating and cooling bills would go down; your energy consumption and carbon emissions would drop; and you’d still be comfortable all year ’round.AeroShield, a startup spun out of MIT, is poised to start manufacturing such windows. Building operations make up 36 percent of global carbon dioxide emissions, and today’s windows are a major contributor to energy inefficiency in buildings. To improve building efficiency, AeroShield has developed a window technology that promises to reduce heat loss by up to 65 percent, significantly reducing energy use and carbon emissions in buildings, and the company just announced the opening of a new facility to manufacture its breakthrough energy-efficient windows.“Our mission is to decarbonize the built environment,” says Elise Strobach SM ’17, PhD ’20, co-founder and CEO of AeroShield. “The availability of affordable, thermally insulating windows will help us achieve that goal while also reducing homeowner’s heating and cooling bills.” According to the U.S. Department of Energy, for most homeowners, 30 percent of that bill results from window inefficiencies.Technology development at MITResearch on AeroShield’s window technology began a decade ago in the MIT lab of Evelyn Wang, Ford Professor of Engineering, now on leave to serve as director of the Advanced Research Projects Agency-Energy (ARPA-E). In late 2014, the MIT team received funding from ARPA-E, and other sponsors followed, including the MIT Energy Initiative through the MIT Tata Center for Technology and Design in 2016.The work focused on aerogels, remarkable materials that are ultra-porous, lighter than a marshmallow, strong enough to support a brick, and an unparalleled barrier to heat flow. Aerogels were invented in the 1930s and used by NASA and others as thermal insulation. The team at MIT saw the potential for incorporating aerogel sheets into windows to keep heat from escaping or entering buildings. But there was one problem: Nobody had been able to make aerogels transparent.An aerogel is made of transparent, loosely connected nanoscale silica particles and is 95 percent air. But an aerogel sheet isn’t transparent because light traveling through it gets scattered by the silica particles.After five years of theoretical and experimental work, the MIT team determined that the key to transparency was having the silica particles both small and uniform in size. This allows light to pass directly through, so the aerogel becomes transparent. Indeed, as long as the particle size is small and uniform, increasing the thickness of an aerogel sheet to achieve greater thermal insulation won’t make it less clear.Teams in the MIT lab looked at various applications for their super-insulating, transparent aerogels. Some focused on improving solar thermal collectors by making the systems more efficient and less expensive. But to Strobach, increasing the thermal efficiency of windows looked especially promising and potentially significant as a means of reducing climate change.The researchers determined that aerogel sheets could be inserted into the gap in double-pane windows, making them more than twice as insulating. The windows could then be manufactured on existing production lines with minor changes, and the resulting windows would be affordable and as wide-ranging in style as the window options available today. Best of all, once purchased and installed, the windows would reduce electricity bills, energy use, and carbon emissions.The impact on energy use in buildings could be considerable. “If we only consider winter, windows in the United States lose enough energy to power over 50 million homes,” says Strobach. “That wasted energy generates about 350 million tons of carbon dioxide — more than is emitted by 76 million cars.” Super-insulating windows could help home and building owners reduce carbon dioxide emissions by gigatons while saving billions in heating and cooling costs.The AeroShield storyIn 2019, Strobach and her MIT colleagues — Aaron Baskerville-Bridges MBA ’20, SM ’20 and Kyle Wilke PhD ’19 — co-founded AeroShield to further develop and commercialize their aerogel-based technology for windows and other applications. And in the subsequent five years, their hard work has attracted attention, recently leading to two major accomplishments.In spring 2024, the company announced the opening of its new pilot manufacturing facility in Waltham, Massachusetts, where the team will be producing, testing, and certifying their first full-size windows and patio doors for initial product launch. The 12,000 square foot facility will significantly expand the company’s capabilities, with cutting-edge aerogel R&D labs, manufacturing equipment, assembly lines, and testing equipment. Says Strobach, “Our pilot facility will supply window and door manufacturers as we launch our first products and will also serve as our R&D headquarters as we develop the next generation of energy-efficient products using transparent aerogels.”Also in spring 2024, AeroShield received a $14.5 million award from ARPA-E’s “Seeding Critical Advances for Leading Energy technologies with Untapped Potential” (SCALEUP) program, which provides new funding to previous ARPA-E awardees that have “demonstrated a viable path to market.” That funding will enable the company to expand its production capacity to tens of thousands, or even hundreds of thousands, of units per year.Strobach also cites two less-obvious benefits of the SCALEUP award.First, the funding is enabling the company to move more quickly on the scale-up phase of their technology development. “We know from our fundamental studies and lab experiments that we can make large-area aerogel sheets that could go in an entry or patio door,” says Elise. “The SCALEUP award allows us to go straight for that vision. We don’t have to do all the incremental sizes of aerogels to prove that we can make a big one. The award provides capital for us to buy the big equipment to make the big aerogel.”Second, the SCALEUP award confirms the viability of the company to other potential investors and collaborators. Indeed, AeroShield recently announced $5 million of additional funding from existing investors Massachusetts Clean Energy Center and MassVentures, as well as new investor MassMutual Ventures. Strobach notes that the company now has investor, engineering, and customer partners.She stresses the importance of partners in achieving AeroShield’s mission. “We know that what we’ve got from a fundamental perspective can change the industry,” she says. “Now we want to go out and do it. With the right partners and at the right pace, we may actually be able to increase the energy efficiency of our buildings early enough to help make a real dent in climate change.” More

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      Study of disordered rock salts leads to battery breakthrough

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      For the past decade, disordered rock salt has been studied as a potential breakthrough cathode material for use in lithium-ion batteries and a key to creating low-cost, high-energy storage for everything from cell phones to electric vehicles to renewable energy storage.A new MIT study is making sure the material fulfills that promise.Led by Ju Li, the Tokyo Electric Power Company Professor in Nuclear Engineering and professor of materials science and engineering, a team of researchers describe a new class of partially disordered rock salt cathode, integrated with polyanions — dubbed disordered rock salt-polyanionic spinel, or DRXPS — that delivers high energy density at high voltages with significantly improved cycling stability.“There is typically a trade-off in cathode materials between energy density and cycling stability … and with this work we aim to push the envelope by designing new cathode chemistries,” says Yimeng Huang, a postdoc in the Department of Nuclear Science and Engineering and first author of a paper describing the work published today in Nature Energy. “(This) material family has high energy density and good cycling stability because it integrates two major types of cathode materials, rock salt and polyanionic olivine, so it has the benefits of both.”Importantly, Li adds, the new material family is primarily composed of manganese, an earth-abundant element that is significantly less expensive than elements like nickel and cobalt, which are typically used in cathodes today.“Manganese is at least five times less expensive than nickel, and about 30 times less expensive than cobalt,” Li says. “Manganese is also the one of the keys to achieving higher energy densities, so having that material be much more earth-abundant is a tremendous advantage.”A possible path to renewable energy infrastructureThat advantage will be particularly critical, Li and his co-authors wrote, as the world looks to build the renewable energy infrastructure needed for a low- or no-carbon future.Batteries are a particularly important part of that picture, not only for their potential to decarbonize transportation with electric cars, buses, and trucks, but also because they will be essential to addressing the intermittency issues of wind and solar power by storing excess energy, then feeding it back into the grid at night or on calm days, when renewable generation drops.Given the high cost and relative rarity of materials like cobalt and nickel, they wrote, efforts to rapidly scale up electric storage capacity would likely lead to extreme cost spikes and potentially significant materials shortages.“If we want to have true electrification of energy generation, transportation, and more, we need earth-abundant batteries to store intermittent photovoltaic and wind power,” Li says. “I think this is one of the steps toward that dream.”That sentiment was shared by Gerbrand Ceder, the Samsung Distinguished Chair in Nanoscience and Nanotechnology Research and a professor of materials science and engineering at the University of California at Berkeley.“Lithium-ion batteries are a critical part of the clean energy transition,” Ceder says. “Their continued growth and price decrease depends on the development of inexpensive, high-performance cathode materials made from earth-abundant materials, as presented in this work.”Overcoming obstacles in existing materialsThe new study addresses one of the major challenges facing disordered rock salt cathodes — oxygen mobility.While the materials have long been recognized for offering very high capacity — as much as 350 milliampere-hour per gram — as compared to traditional cathode materials, which typically have capacities of between 190 and 200 milliampere-hour per gram, it is not very stable.The high capacity is contributed partially by oxygen redox, which is activated when the cathode is charged to high voltages. But when that happens, oxygen becomes mobile, leading to reactions with the electrolyte and degradation of the material, eventually leaving it effectively useless after prolonged cycling.To overcome those challenges, Huang added another element — phosphorus — that essentially acts like a glue, holding the oxygen in place to mitigate degradation.“The main innovation here, and the theory behind the design, is that Yimeng added just the right amount of phosphorus, formed so-called polyanions with its neighboring oxygen atoms, into a cation-deficient rock salt structure that can pin them down,” Li explains. “That allows us to basically stop the percolating oxygen transport due to strong covalent bonding between phosphorus and oxygen … meaning we can both utilize the oxygen-contributed capacity, but also have good stability as well.”That ability to charge batteries to higher voltages, Li says, is crucial because it allows for simpler systems to manage the energy they store.“You can say the quality of the energy is higher,” he says. “The higher the voltage per cell, then the less you need to connect them in series in the battery pack, and the simpler the battery management system.”Pointing the way to future studiesWhile the cathode material described in the study could have a transformative impact on lithium-ion battery technology, there are still several avenues for study going forward.Among the areas for future study, Huang says, are efforts to explore new ways to fabricate the material, particularly for morphology and scalability considerations.“Right now, we are using high-energy ball milling for mechanochemical synthesis, and … the resulting morphology is non-uniform and has small average particle size (about 150 nanometers). This method is also not quite scalable,” he says. “We are trying to achieve a more uniform morphology with larger particle sizes using some alternate synthesis methods, which would allow us to increase the volumetric energy density of the material and may allow us to explore some coating methods … which could further improve the battery performance. The future methods, of course, should be industrially scalable.”In addition, he says, the disordered rock salt material by itself is not a particularly good conductor, so significant amounts of carbon — as much as 20 weight percent of the cathode paste — were added to boost its conductivity. If the team can reduce the carbon content in the electrode without sacrificing performance, there will be higher active material content in a battery, leading to an increased practical energy density.“In this paper, we just used Super P, a typical conductive carbon consisting of nanospheres, but they’re not very efficient,” Huang says. “We are now exploring using carbon nanotubes, which could reduce the carbon content to just 1 or 2 weight percent, which could allow us to dramatically increase the amount of the active cathode material.”Aside from decreasing carbon content, making thick electrodes, he adds, is yet another way to increase the practical energy density of the battery. This is another area of research that the team is working on.“This is only the beginning of DRXPS research, since we only explored a few chemistries within its vast compositional space,” he continues. “We can play around with different ratios of lithium, manganese, phosphorus, and oxygen, and with various combinations of other polyanion-forming elements such as boron, silicon, and sulfur.”With optimized compositions, more scalable synthesis methods, better morphology that allows for uniform coatings, lower carbon content, and thicker electrodes, he says, the DRXPS cathode family is very promising in applications of electric vehicles and grid storage, and possibly even in consumer electronics, where the volumetric energy density is very important.This work was supported with funding from the Honda Research Institute USA Inc. and the Molecular Foundry at Lawrence Berkeley National Laboratory, and used resources of the National Synchrotron Light Source II at Brookhaven National Laboratory and the Advanced Photon Source at Argonne National Laboratory.  More

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      in Energy

      More durable metals for fusion power reactors

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      For many decades, nuclear fusion power has been viewed as the ultimate energy source. A fusion power plant could generate carbon-free energy at a scale needed to address climate change. And it could be fueled by deuterium recovered from an essentially endless source — seawater.Decades of work and billions of dollars in research funding have yielded many advances, but challenges remain. To Ju Li, the TEPCO Professor in Nuclear Science and Engineering and a professor of materials science and engineering at MIT, there are still two big challenges. The first is to build a fusion power plant that generates more energy than is put into it; in other words, it produces a net output of power. Researchers worldwide are making progress toward meeting that goal.The second challenge that Li cites sounds straightforward: “How do we get the heat out?” But understanding the problem and finding a solution are both far from obvious.Research in the MIT Energy Initiative (MITEI) includes development and testing of advanced materials that may help address those challenges, as well as many other challenges of the energy transition. MITEI has multiple corporate members that have been supporting MIT’s efforts to advance technologies required to harness fusion energy.The problem: An abundance of helium, a destructive forceKey to a fusion reactor is a superheated plasma — an ionized gas — that’s reacting inside a vacuum vessel. As light atoms in the plasma combine to form heavier ones, they release fast neutrons with high kinetic energy that shoot through the surrounding vacuum vessel into a coolant. During this process, those fast neutrons gradually lose their energy by causing radiation damage and generating heat. The heat that’s transferred to the coolant is eventually used to raise steam that drives an electricity-generating turbine.The problem is finding a material for the vacuum vessel that remains strong enough to keep the reacting plasma and the coolant apart, while allowing the fast neutrons to pass through to the coolant. If one considers only the damage due to neutrons knocking atoms out of position in the metal structure, the vacuum vessel should last a full decade. However, depending on what materials are used in the fabrication of the vacuum vessel, some projections indicate that the vacuum vessel will last only six to 12 months. Why is that? Today’s nuclear fission reactors also generate neutrons, and those reactors last far longer than a year.The difference is that fusion neutrons possess much higher kinetic energy than fission neutrons do, and as they penetrate the vacuum vessel walls, some of them interact with the nuclei of atoms in the structural material, giving off particles that rapidly turn into helium atoms. The result is hundreds of times more helium atoms than are present in a fission reactor. Those helium atoms look for somewhere to land — a place with low “embedding energy,” a measure that indicates how much energy it takes for a helium atom to be absorbed. As Li explains, “The helium atoms like to go to places with low helium embedding energy.” And in the metals used in fusion vacuum vessels, there are places with relatively low helium embedding energy — namely, naturally occurring openings called grain boundaries.Metals are made up of individual grains inside which atoms are lined up in an orderly fashion. Where the grains come together there are gaps where the atoms don’t line up as well. That open space has relatively low helium embedding energy, so the helium atoms congregate there. Worse still, helium atoms have a repellent interaction with other atoms, so the helium atoms basically push open the grain boundary. Over time, the opening grows into a continuous crack, and the vacuum vessel breaks.That congregation of helium atoms explains why the structure fails much sooner than expected based just on the number of helium atoms that are present. Li offers an analogy to illustrate. “Babylon is a city of a million people. But the claim is that 100 bad persons can destroy the whole city — if all those bad persons work at the city hall.” The solution? Give those bad persons other, more attractive places to go, ideally in their own villages.To Li, the problem and possible solution are the same in a fusion reactor. If many helium atoms go to the grain boundary at once, they can destroy the metal wall. The solution? Add a small amount of a material that has a helium embedding energy even lower than that of the grain boundary. And over the past two years, Li and his team have demonstrated — both theoretically and experimentally — that their diversionary tactic works. By adding nanoscale particles of a carefully selected second material to the metal wall, they’ve found they can keep the helium atoms that form from congregating in the structurally vulnerable grain boundaries in the metal.Looking for helium-absorbing compoundsTo test their idea, So Yeon Kim ScD ’23 of the Department of Materials Science and Engineering and Haowei Xu PhD ’23 of the Department of Nuclear Science and Engineering acquired a sample composed of two materials, or “phases,” one with a lower helium embedding energy than the other. They and their collaborators then implanted helium ions into the sample at a temperature similar to that in a fusion reactor and watched as bubbles of helium formed. Transmission electron microscope images confirmed that the helium bubbles occurred predominantly in the phase with the lower helium embedding energy. As Li notes, “All the damage is in that phase — evidence that it protected the phase with the higher embedding energy.”Having confirmed their approach, the researchers were ready to search for helium-absorbing compounds that would work well with iron, which is often the principal metal in vacuum vessel walls. “But calculating helium embedding energy for all sorts of different materials would be computationally demanding and expensive,” says Kim. “We wanted to find a metric that is easy to compute and a reliable indicator of helium embedding energy.”They found such a metric: the “atomic-scale free volume,” which is basically the maximum size of the internal vacant space available for helium atoms to potentially settle. “This is just the radius of the largest sphere that can fit into a given crystal structure,” explains Kim. “It is a simple calculation.” Examination of a series of possible helium-absorbing ceramic materials confirmed that atomic free volume correlates well with helium embedding energy. Moreover, many of the ceramics they investigated have higher free volume, thus lower embedding energy, than the grain boundaries do.However, in order to identify options for the nuclear fusion application, the screening needed to include some other factors. For example, in addition to the atomic free volume, a good second phase must be mechanically robust (able to sustain a load); it must not get very radioactive with neutron exposure; and it must be compatible — but not too cozy — with the surrounding metal, so it disperses well but does not dissolve into the metal. “We want to disperse the ceramic phase uniformly in the bulk metal to ensure that all grain boundary regions are close to the dispersed ceramic phase so it can provide protection to those regions,” says Li. “The two phases need to coexist, so the ceramic won’t either clump together or totally dissolve in the iron.”Using their analytical tools, Kim and Xu examined about 50,000 compounds and identified 750 potential candidates. Of those, a good option for inclusion in a vacuum vessel wall made mainly of iron was iron silicate.Experimental testingThe researchers were ready to examine samples in the lab. To make the composite material for proof-of-concept demonstrations, Kim and collaborators dispersed nanoscale particles of iron silicate into iron and implanted helium into that composite material. She took X-ray diffraction (XRD) images before and after implanting the helium and also computed the XRD patterns. The ratio between the implanted helium and the dispersed iron silicate was carefully controlled to allow a direct comparison between the experimental and computed XRD patterns. The measured XRD intensity changed with the helium implantation exactly as the calculations had predicted. “That agreement confirms that atomic helium is being stored within the bulk lattice of the iron silicate,” says Kim.To follow up, Kim directly counted the number of helium bubbles in the composite. In iron samples without the iron silicate added, grain boundaries were flanked by many helium bubbles. In contrast, in the iron samples with the iron silicate ceramic phase added, helium bubbles were spread throughout the material, with many fewer occurring along the grain boundaries. Thus, the iron silicate had provided sites with low helium-embedding energy that lured the helium atoms away from the grain boundaries, protecting those vulnerable openings and preventing cracks from opening up and causing the vacuum vessel to fail catastrophically.The researchers conclude that adding just 1 percent (by volume) of iron silicate to the iron walls of the vacuum vessel will cut the number of helium bubbles in half and also reduce their diameter by 20 percent — “and having a lot of small bubbles is OK if they’re not in the grain boundaries,” explains Li.Next stepsThus far, Li and his team have gone from computational studies of the problem and a possible solution to experimental demonstrations that confirm their approach. And they’re well on their way to commercial fabrication of components. “We’ve made powders that are compatible with existing commercial 3D printers and are preloaded with helium-absorbing ceramics,” says Li. The helium-absorbing nanoparticles are well dispersed and should provide sufficient helium uptake to protect the vulnerable grain boundaries in the structural metals of the vessel walls. While Li confirms that there’s more scientific and engineering work to be done, he, along with Alexander O’Brien PhD ’23 of the Department of Nuclear Science and Engineering and Kang Pyo So, a former postdoc in the same department, have already developed a startup company that’s ready to 3D print structural materials that can meet all the challenges faced by the vacuum vessel inside a fusion reactor.This research was supported by Eni S.p.A. through the MIT Energy Initiative. Additional support was provided by a Kwajeong Scholarship; the U.S. Department of Energy (DOE) Laboratory Directed Research and Development program at Idaho National Laboratory; U.S. DOE Lawrence Livermore National Laboratory; and Creative Materials Discovery Program through the National Research Foundation of Korea. More

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      in Security

      Scientists develop an affordable sensor for lead contamination

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      Engineers at MIT, Nanytang Technological University, and several companies have developed a compact and inexpensive technology for detecting and measuring lead concentrations in water, potentially enabling a significant advance in tackling this persistent global health issue.The World Health Organization estimates that 240 million people worldwide are exposed to drinking water that contains unsafe amounts of toxic lead, which can affect brain development in children, cause birth defects, and produce a variety of neurological, cardiac, and other damaging effects. In the United States alone, an estimated 10 million households still get drinking water delivered through lead pipes.“It’s an unaddressed public health crisis that leads to over 1 million deaths annually,” says Jia Xu Brian Sia, an MIT postdoc and the senior author of the paper describing the new technology.But testing for lead in water requires expensive, cumbersome equipment and typically requires days to get results. Or, it uses simple test strips that simply reveal a yes-or-no answer about the presence of lead but no information about its concentration. Current EPA regulations require drinking water to contain no more that 15 parts per billion of lead, a concentration so low it is difficult to detect.The new system, which could be ready for commercial deployment within two or three years, could detect lead concentrations as low as 1 part per billion, with high accuracy, using a simple chip-based detector housed in a handheld device. The technology gives nearly instant quantitative measurements and requires just a droplet of water.The findings are described in a paper appearing today in the journal Nature Communications, by Sia, MIT graduate student and lead author Luigi Ranno, Professor Juejun Hu, and 12 others at MIT and other institutions in academia and industry.The team set out to find a simple detection method based on the use of photonic chips, which use light to perform measurements. The challenging part was finding a way to attach to the photonic chip surface certain ring-shaped molecules known as crown ethers, which can capture specific ions such as lead. After years of effort, they were able to achieve that attachment via a chemical process known as Fischer esterification. “That is one of the essential breakthroughs we have made in this technology,” Sia says.In testing the new chip, the researchers showed that it can detect lead in water at concentrations as low as one part per billion. At much higher concentrations, which may be relevant for testing environmental contamination such as mine tailings, the accuracy is within 4 percent.The device works in water with varying levels of acidity, ranging from pH values of 6 to 8, “which covers most environmental samples,” Sia says. They have tested the device with seawater as well as tap water, and verified the accuracy of the measurements.In order to achieve such levels of accuracy, current testing requires a device called an inductive coupled plasma mass spectrometer. “These setups can be big and expensive,” Sia says. The sample processing can take days and requires experienced technical personnel.While the new chip system they developed is “the core part of the innovation,” Ranno says, further work will be needed to develop this into an integrated, handheld device for practical use. “For making an actual product, you would need to package it into a usable form factor,” he explains. This would involve having a small chip-based laser coupled to the photonic chip. “It’s a matter of mechanical design, some optical design, some chemistry, and figuring out the supply chain,” he says. While that takes time, he says, the underlying concepts are straightforward.The system can be adapted to detect other similar contaminants in water, including cadmium, copper, lithium, barium, cesium, and radium, Ranno says. The device could be used with simple cartridges that can be swapped out to detect different elements, each using slightly different crown ethers that can bind to a specific ion.“There’s this problem that people don’t measure their water enough, especially in the developing countries,” Ranno says. “And that’s because they need to collect the water, prepare the sample, and bring it to these huge instruments that are extremely expensive.” Instead, “having this handheld device, something compact that even untrained personnel can just bring to the source for on-site monitoring, at low costs,” could make regular, ongoing widespread testing feasible.Hu, who is the John F. Elliott Professor of Materials Science and Engineering, says, “I’m hoping this will be quickly implemented, so we can benefit human society. This is a good example of a technology coming from a lab innovation where it may actually make a very tangible impact on society, which is of course very fulfilling.”“If this study can be extended to simultaneous detection of multiple metal elements, especially the presently concerning radioactive elements, its potential would be immense,” says Hou Wang, an associate professor of environmental science and engineering at Hunan University in China, who was not associated with this work.Wang adds, “This research has engineered a sensor capable of instantaneously detecting lead concentration in water. This can be utilized in real-time to monitor the lead pollution concentration in wastewater discharged from industries such as battery manufacturing and lead smelting, facilitating the establishment of industrial wastewater monitoring systems. I think the innovative aspects and developmental potential of this research are quite commendable.”Wang Qian, a principal research scientist at the Institute of Materials Research in Singapore, who also was not affiliated with this work, says, “The ability for the pervasive, portable, and quantitative detection of lead has proved to be challenging primarily due to cost concerns. This work demonstrates the potential to do so in a highly integrated form factor and is compatible with large-scale, low-cost manufacturing.”The team included researchers at MIT, at Nanyang Technological University and Temasek Laboratories in Singapore, at the University of Southampton in the U.K., and at companies Fingate Technologies, in Singapore, and Vulcan Photonics, headquartered in Malaysia. The work used facilities at MIT.nano, the Harvard University Center for Nanoscale Systems, NTU’s Center for Micro- and Nano-Electronics, and the Nanyang Nanofabrication Center. More

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      Exploring frontiers of mechanical engineering

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      From cutting-edge robotics, design, and bioengineering to sustainable energy solutions, ocean engineering, nanotechnology, and innovative materials science, MechE students and their advisors are doing incredibly innovative work. The graduate students highlighted here represent a snapshot of the great work in progress this spring across the Department of Mechanical Engineering, and demonstrate the ways the future of this field is as limitless as the imaginations of its practitioners.Democratizing design through AILyle RegenwetterHometown: Champaign, IllinoisAdvisor: Assistant Professor Faez AhmedInterests: Food, climbing, skiing, soccer, tennis, cookingLyle Regenwetter finds excitement in the prospect of generative AI to “democratize” design and enable inexperienced designers to tackle complex design problems. His research explores new training methods through which generative AI models can be taught to implicitly obey design constraints and synthesize higher-performing designs. Knowing that prospective designers often have an intimate knowledge of the needs of users, but may otherwise lack the technical training to create solutions, Regenwetter also develops human-AI collaborative tools that allow AI models to interact and support designers in popular CAD software and real design problems. Solving a whale of a problem Loïcka BailleHometown: L’Escale, FranceAdvisor: Daniel ZitterbartInterests: Being outdoors — scuba diving, spelunking, or climbing. Sailing on the Charles River, martial arts classes, and playing volleyballLoïcka Baille’s research focuses on developing remote sensing technologies to study and protect marine life. Her main project revolves around improving onboard whale detection technology to prevent vessel strikes, with a special focus on protecting North Atlantic right whales. Baille is also involved in an ongoing study of Emperor penguins. Her team visits Antarctica annually to tag penguins and gather data to enhance their understanding of penguin population dynamics and draw conclusions regarding the overall health of the ecosystem.Water, water anywhereCarlos Díaz-MarínHometown: San José, Costa RicaAdvisor: Professor Gang Chen | Former Advisor: Professor Evelyn WangInterests: New England hiking, biking, and dancingCarlos Díaz-Marín designs and synthesizes inexpensive salt-polymer materials that can capture large amounts of humidity from the air. He aims to change the way we generate potable water from the air, even in arid conditions. In addition to water generation, these salt-polymer materials can also be used as thermal batteries, capable of storing and reusing heat. Beyond the scientific applications, Díaz-Marín is excited to continue doing research that can have big social impacts, and that finds and explains new physical phenomena. As a LatinX person, Díaz-Marín is also driven to help increase diversity in STEM.Scalable fabrication of nano-architected materialsSomayajulu DhulipalaHometown: Hyderabad, IndiaAdvisor: Assistant Professor Carlos PortelaInterests: Space exploration, taekwondo, meditation.Somayajulu Dhulipala works on developing lightweight materials with tunable mechanical properties. He is currently working on methods for the scalable fabrication of nano-architected materials and predicting their mechanical properties. The ability to fine-tune the mechanical properties of specific materials brings versatility and adaptability, making these materials suitable for a wide range of applications across multiple industries. While the research applications are quite diverse, Dhulipala is passionate about making space habitable for humanity, a crucial step toward becoming a spacefaring civilization.Ingestible health-care devicesJimmy McRaeHometown: Woburn, MassachusettsAdvisor: Associate Professor Giovani TraversoInterests: Anything basketball-related: playing, watching, going to games, organizing hometown tournaments Jimmy McRae aims to drastically improve diagnostic and therapeutic capabilities through noninvasive health-care technologies. His research focuses on leveraging materials, mechanics, embedded systems, and microfabrication to develop novel ingestible electronic and mechatronic devices. This ranges from ingestible electroceutical capsules that modulate hunger-regulating hormones to devices capable of continuous ultralong monitoring and remotely triggerable actuations from within the stomach. The principles that guide McRae’s work to develop devices that function in extreme environments can be applied far beyond the gastrointestinal tract, with applications for outer space, the ocean, and more.Freestyle BMX meets machine learningEva NatesHometown: Narberth, Pennsylvania Advisor: Professor Peko HosoiInterests: Rowing, running, biking, hiking, bakingEva Nates is working with the Australian Cycling Team to create a tool to classify Bicycle Motocross Freestyle (BMX FS) tricks. She uses a singular value decomposition method to conduct a principal component analysis of the time-dependent point-tracking data of an athlete and their bike during a run to classify each trick. The 2024 Olympic team hopes to incorporate this tool in their training workflow, and Nates worked alongside the team at their facilities on the Gold Coast of Australia during MIT’s Independent Activities Period in January.Augmenting Astronauts with Wearable Limbs Erik BallesterosHometown: Spring, TexasAdvisor: Professor Harry AsadaInterests: Cosplay, Star Wars, Lego bricksErik Ballesteros’s research seeks to support astronauts who are conducting planetary extravehicular activities through the use of supernumerary robotic limbs (SuperLimbs). His work is tailored toward design and control manifestation to assist astronauts with post-fall recovery, human-leader/robot-follower quadruped locomotion, and coordinated manipulation between the SuperLimbs and the astronaut to perform tasks like excavation and sample handling.This article appeared in the Spring 2024 edition of the Department of Mechanical Engineering’s magazine, MechE Connects.  More

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      in Environment

      How light can vaporize water without the need for heat

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      It’s the most fundamental of processes — the evaporation of water from the surfaces of oceans and lakes, the burning off of fog in the morning sun, and the drying of briny ponds that leaves solid salt behind. Evaporation is all around us, and humans have been observing it and making use of it for as long as we have existed.

      And yet, it turns out, we’ve been missing a major part of the picture all along.

      In a series of painstakingly precise experiments, a team of researchers at MIT has demonstrated that heat isn’t alone in causing water to evaporate. Light, striking the water’s surface where air and water meet, can break water molecules away and float them into the air, causing evaporation in the absence of any source of heat.

      The astonishing new discovery could have a wide range of significant implications. It could help explain mysterious measurements over the years of how sunlight affects clouds, and therefore affect calculations of the effects of climate change on cloud cover and precipitation. It could also lead to new ways of designing industrial processes such as solar-powered desalination or drying of materials.

      The findings, and the many different lines of evidence that demonstrate the reality of the phenomenon and the details of how it works, are described today in the journal PNAS, in a paper by Carl Richard Soderberg Professor of Power Engineering Gang Chen, postdocs Guangxin Lv and Yaodong Tu, and graduate student James Zhang.

      The authors say their study suggests that the effect should happen widely in nature— everywhere from clouds to fogs to the surfaces of oceans, soils, and plants — and that it could also lead to new practical applications, including in energy and clean water production. “I think this has a lot of applications,” Chen says. “We’re exploring all these different directions. And of course, it also affects the basic science, like the effects of clouds on climate, because clouds are the most uncertain aspect of climate models.”

      A newfound phenomenon

      The new work builds on research reported last year, which described this new “photomolecular effect” but only under very specialized conditions: on the surface of specially prepared hydrogels soaked with water. In the new study, the researchers demonstrate that the hydrogel is not necessary for the process; it occurs at any water surface exposed to light, whether it’s a flat surface like a body of water or a curved surface like a droplet of cloud vapor.

      Because the effect was so unexpected, the team worked to prove its existence with as many different lines of evidence as possible. In this study, they report 14 different kinds of tests and measurements they carried out to establish that water was indeed evaporating — that is, molecules of water were being knocked loose from the water’s surface and wafted into the air — due to the light alone, not by heat, which was long assumed to be the only mechanism involved.

      One key indicator, which showed up consistently in four different kinds of experiments under different conditions, was that as the water began to evaporate from a test container under visible light, the air temperature measured above the water’s surface cooled down and then leveled off, showing that thermal energy was not the driving force behind the effect.

      Other key indicators that showed up included the way the evaporation effect varied depending on the angle of the light, the exact color of the light, and its polarization. None of these varying characteristics should happen because at these wavelengths, water hardly absorbs light at all — and yet the researchers observed them.

      The effect is strongest when light hits the water surface at an angle of 45 degrees. It is also strongest with a certain type of polarization, called transverse magnetic polarization. And it peaks in green light — which, oddly, is the color for which water is most transparent and thus interacts the least.

      Chen and his co-researchers have proposed a physical mechanism that can explain the angle and polarization dependence of the effect, showing that the photons of light can impart a net force on water molecules at the water surface that is sufficient to knock them loose from the body of water. But they cannot yet account for the color dependence, which they say will require further study.

      They have named this the photomolecular effect, by analogy with the photoelectric effect that was discovered by Heinrich Hertz in 1887 and finally explained by Albert Einstein in 1905. That effect was one of the first demonstrations that light also has particle characteristics, which had major implications in physics and led to a wide variety of applications, including LEDs. Just as the photoelectric effect liberates electrons from atoms in a material in response to being hit by a photon of light, the photomolecular effect shows that photons can liberate entire molecules from a liquid surface, the researchers say.

      “The finding of evaporation caused by light instead of heat provides new disruptive knowledge of light-water interaction,” says Xiulin Ruan, professor of mechanical engineering at Purdue University, who was not involved in the study. “It could help us gain new understanding of how sunlight interacts with cloud, fog, oceans, and other natural water bodies to affect weather and climate. It has significant potential practical applications such as high-performance water desalination driven by solar energy. This research is among the rare group of truly revolutionary discoveries which are not widely accepted by the community right away but take time, sometimes a long time, to be confirmed.”

      Solving a cloud conundrum

      The finding may solve an 80-year-old mystery in climate science. Measurements of how clouds absorb sunlight have often shown that they are absorbing more sunlight than conventional physics dictates possible. The additional evaporation caused by this effect could account for the longstanding discrepancy, which has been a subject of dispute since such measurements are difficult to make.

      “Those experiments are based on satellite data and flight data,“ Chen explains. “They fly an airplane on top of and below the clouds, and there are also data based on the ocean temperature and radiation balance. And they all conclude that there is more absorption by clouds than theory could calculate. However, due to the complexity of clouds and the difficulties of making such measurements, researchers have been debating whether such discrepancies are real or not. And what we discovered suggests that hey, there’s another mechanism for cloud absorption, which was not accounted for, and this mechanism might explain the discrepancies.”

      Chen says he recently spoke about the phenomenon at an American Physical Society conference, and one physicist there who studies clouds and climate said they had never thought about this possibility, which could affect calculations of the complex effects of clouds on climate. The team conducted experiments using LEDs shining on an artificial cloud chamber, and they observed heating of the fog, which was not supposed to happen since water does not absorb in the visible spectrum. “Such heating can be explained based on the photomolecular effect more easily,” he says.

      Lv says that of the many lines of evidence, “the flat region in the air-side temperature distribution above hot water will be the easiest for people to reproduce.” That temperature profile “is a signature” that demonstrates the effect clearly, he says.

      Zhang adds: “It is quite hard to explain how this kind of flat temperature profile comes about without invoking some other mechanism” beyond the accepted theories of thermal evaporation. “It ties together what a whole lot of people are reporting in their solar desalination devices,” which again show evaporation rates that cannot be explained by the thermal input.

      The effect can be substantial. Under the optimum conditions of color, angle, and polarization, Lv says, “the evaporation rate is four times the thermal limit.”

      Already, since publication of the first paper, the team has been approached by companies that hope to harness the effect, Chen says, including for evaporating syrup and drying paper in a paper mill. The likeliest first applications will come in the areas of solar desalinization systems or other industrial drying processes, he says. “Drying consumes 20 percent of all industrial energy usage,” he points out.

      Because the effect is so new and unexpected, Chen says, “This phenomenon should be very general, and our experiment is really just the beginning.” The experiments needed to demonstrate and quantify the effect are very time-consuming. “There are many variables, from understanding water itself, to extending to other materials, other liquids and even solids,” he says.

      “The observations in the manuscript points to a new physical mechanism that foundationally alters our thinking on the kinetics of evaporation,” says Shannon Yee, an associate professor of mechanical engineering at Georgia Tech, who was not associated with this work. He adds, “Who would have thought that we are still learning about something as quotidian as water evaporating?”

      “I think this work is very significant scientifically because it presents a new mechanism,” says University of Alberta Distinguished Professor Janet A.W. Elliott, who also was not associated with this work. “It may also turn out to be practically important for technology and our understanding of nature, because evaporation of water is ubiquitous and the effect appears to deliver significantly higher evaporation rates than the known thermal mechanism. …  My overall impression is this work is outstanding. It appears to be carefully done with many precise experiments lending support for one another.”

      The work was partly supported by an MIT Bose Award. More

    • 88 Shares179 Views

      in Energy

      Propelling atomically layered magnets toward green computers

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      Globally, computation is booming at an unprecedented rate, fueled by the boons of artificial intelligence. With this, the staggering energy demand of the world’s computing infrastructure has become a major concern, and the development of computing devices that are far more energy-efficient is a leading challenge for the scientific community. 

      Use of magnetic materials to build computing devices like memories and processors has emerged as a promising avenue for creating “beyond-CMOS” computers, which would use far less energy compared to traditional computers. Magnetization switching in magnets can be used in computation the same way that a transistor switches from open or closed to represent the 0s and 1s of binary code. 

      While much of the research along this direction has focused on using bulk magnetic materials, a new class of magnetic materials — called two-dimensional van der Waals magnets — provides superior properties that can improve the scalability and energy efficiency of magnetic devices to make them commercially viable. 

      Although the benefits of shifting to 2D magnetic materials are evident, their practical induction into computers has been hindered by some fundamental challenges. Until recently, 2D magnetic materials could operate only at very low temperatures, much like superconductors. So bringing their operating temperatures above room temperature has remained a primary goal. Additionally, for use in computers, it is important that they can be controlled electrically, without the need for magnetic fields. Bridging this fundamental gap, where 2D magnetic materials can be electrically switched above room temperature without any magnetic fields, could potentially catapult the translation of 2D magnets into the next generation of “green” computers.

      A team of MIT researchers has now achieved this critical milestone by designing a “van der Waals atomically layered heterostructure” device where a 2D van der Waals magnet, iron gallium telluride, is interfaced with another 2D material, tungsten ditelluride. In an open-access paper published March 15 in Science Advances, the team shows that the magnet can be toggled between the 0 and 1 states simply by applying pulses of electrical current across their two-layer device. 

      Play video

      The Future of Spintronics: Manipulating Spins in Atomic Layers without External Magnetic FieldsVideo: Deblina Sarkar

      “Our device enables robust magnetization switching without the need for an external magnetic field, opening up unprecedented opportunities for ultra-low power and environmentally sustainable computing technology for big data and AI,” says lead author Deblina Sarkar, the AT&T Career Development Assistant Professor at the MIT Media Lab and Center for Neurobiological Engineering, and head of the Nano-Cybernetic Biotrek research group. “Moreover, the atomically layered structure of our device provides unique capabilities including improved interface and possibilities of gate voltage tunability, as well as flexible and transparent spintronic technologies.”

      Sarkar is joined on the paper by first author Shivam Kajale, a graduate student in Sarkar’s research group at the Media Lab; Thanh Nguyen, a graduate student in the Department of Nuclear Science and Engineering (NSE); Nguyen Tuan Hung, an MIT visiting scholar in NSE and an assistant professor at Tohoku University in Japan; and Mingda Li, associate professor of NSE.

      Breaking the mirror symmetries 

      When electric current flows through heavy metals like platinum or tantalum, the electrons get segregated in the materials based on their spin component, a phenomenon called the spin Hall effect, says Kajale. The way this segregation happens depends on the material, and particularly its symmetries.

      “The conversion of electric current to spin currents in heavy metals lies at the heart of controlling magnets electrically,” Kajale notes. “The microscopic structure of conventionally used materials, like platinum, have a kind of mirror symmetry, which restricts the spin currents only to in-plane spin polarization.”

      Kajale explains that two mirror symmetries must be broken to produce an “out-of-plane” spin component that can be transferred to a magnetic layer to induce field-free switching. “Electrical current can ‘break’ the mirror symmetry along one plane in platinum, but its crystal structure prevents the mirror symmetry from being broken in a second plane.”

      In their earlier experiments, the researchers used a small magnetic field to break the second mirror plane. To get rid of the need for a magnetic nudge, Kajale and Sarkar and colleagues looked instead for a material with a structure that could break the second mirror plane without outside help. This led them to another 2D material, tungsten ditelluride. The tungsten ditelluride that the researchers used has an orthorhombic crystal structure. The material itself has one broken mirror plane. Thus, by applying current along its low-symmetry axis (parallel to the broken mirror plane), the resulting spin current has an out-of-plane spin component that can directly induce switching in the ultra-thin magnet interfaced with the tungsten ditelluride. 

      “Because it’s also a 2D van der Waals material, it can also ensure that when we stack the two materials together, we get pristine interfaces and a good flow of electron spins between the materials,” says Kajale. 

      Becoming more energy-efficient 

      Computer memory and processors built from magnetic materials use less energy than traditional silicon-based devices. And the van der Waals magnets can offer higher energy efficiency and better scalability compared to bulk magnetic material, the researchers note. 

      The electrical current density used for switching the magnet translates to how much energy is dissipated during switching. A lower density means a much more energy-efficient material. “The new design has one of the lowest current densities in van der Waals magnetic materials,” Kajale says. “This new design has an order of magnitude lower in terms of the switching current required in bulk materials. This translates to something like two orders of magnitude improvement in energy efficiency.”

      The research team is now looking at similar low-symmetry van der Waals materials to see if they can reduce current density even further. They are also hoping to collaborate with other researchers to find ways to manufacture the 2D magnetic switch devices at commercial scale. 

      This work was carried out, in part, using the facilities at MIT.nano. It was funded by the Media Lab, the U.S. National Science Foundation, and the U.S. Department of Energy. More

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      in Energy

      New MIT.nano equipment to accelerate innovation in “tough tech” sectors

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      A new set of advanced nanofabrication equipment will make MIT.nano one of the world’s most advanced research facilities in microelectronics and related technologies, unlocking new opportunities for experimentation and widening the path for promising inventions to become impactful new products.

      The equipment, provided by Applied Materials, will significantly expand MIT.nano’s nanofabrication capabilities, making them compatible with wafers — thin, round slices of semiconductor material — up to 200 millimeters, or 8 inches, in diameter, a size widely used in industry. The new tools will allow researchers to prototype a vast array of new microelectronic devices using state-of-the-art materials and fabrication processes. At the same time, the 200-millimeter compatibility will support close collaboration with industry and enable innovations to be rapidly adopted by companies and mass produced.

      MIT.nano’s leaders say the equipment, which will also be available to scientists outside of MIT, will dramatically enhance their facility’s capabilities, allowing experts in the region to more efficiently explore new approaches in “tough tech” sectors, including advanced electronics, next-generation batteries, renewable energies, optical computing, biological sensing, and a host of other areas — many likely yet to be imagined.

      “The toolsets will provide an accelerative boost to our ability to launch new technologies that can then be given to the world at scale,” says MIT.nano Director Vladimir Bulović, who is also the Fariborz Maseeh Professor of Emerging Technology. “MIT.nano is committed to its expansive mission — to build a better world. We provide toolsets and capabilities that, in the hands of brilliant researchers, can effectively move the world forward.”

      The announcement comes as part of an agreement between MIT and Applied Materials, Inc. that, together with a grant to MIT from the Northeast Microelectronics Coalition (NEMC) Hub, commits more than $40 million of estimated private and public investment to add advanced nano-fabrication equipment and capabilities at MIT.nano.

      “We don’t believe there is another space in the United States that will offer the same kind of versatility, capability, and accessibility, with 8-inch toolsets integrated right next to more fundamental toolsets for research discoveries,” Bulović says. “It will create a seamless path to accelerate the pace of innovation.”

      Pushing the boundaries of innovation

      Applied Materials is the world’s largest supplier of equipment for manufacturing semiconductors, displays, and other advanced electronics. The company will provide at MIT.nano several state-of-the-art process tools capable of supporting 150- and 200-millimeter wafers and will enhance and upgrade an existing tool owned by MIT. In addition to assisting MIT.nano in the day-to-day operation and maintenance of the equipment, Applied Materials engineers will develop new process capabilities to benefit researchers and students from MIT and beyond.

      “This investment will significantly accelerate the pace of innovation and discovery in microelectronics and microsystems,” says Tomás Palacios, director of MIT’s Microsystems Technology Laboratories and the Clarence J. Lebel Professor in Electrical Engineering. “It’s wonderful news for our community, wonderful news for the state, and, in my view, a tremendous step forward toward implementing the national vision for the future of innovation in microelectronics.”

      Nanoscale research at universities is traditionally conducted on machines that are less compatible with industry, which makes academic innovations more difficult to turn into impactful, mass-produced products. Jorg Scholvin, associate director for MIT.nano’s shared fabrication facility, says the new machines, when combined with MIT.nano’s existing equipment, represent a step-change improvement in that area: Researchers will be able to take an industry-standard wafer and build their technology on top of it to prove to companies it works on existing devices, or to co-fabricate new ideas in close collaboration with industry partners.

      “In the journey from an idea to a fully working device, the ability to begin on a small scale, figure out what you want to do, rapidly debug your designs, and then scale it up to an industry-scale wafer is critical,” Scholvin says. “It means a student can test out their idea on wafer-scale quickly and directly incorporate insights into their project so that their processes are scalable. Providing such proof-of-principle early on will accelerate the idea out of the academic environment, potentially reducing years of added effort. Other tools at MIT.nano can supplement work on the 200-millimeter wafer scale, but the higher throughput and higher precision of the Applied equipment will provide researchers with repeatability and accuracy that is unprecedented for academic research environments. Essentially what you have is a sharper, faster, more precise tool to do your work.”

      Scholvin predicts the equipment will lead to exponential growth in research opportunities.

      “I think a key benefit of these tools is they allow us to push the boundary of research in a variety of different ways that we can predict today,” Scholvin says. “But then there are also unpredictable benefits, which are hiding in the shadows waiting to be discovered by the creativity of the researchers at MIT. With each new application, more ideas and paths usually come to mind — so that over time, more and more opportunities are discovered.”

      Because the equipment is available for use by people outside of the MIT community, including regional researchers, industry partners, nonprofit organizations, and local startups, they will also enable new collaborations.

      “The tools themselves will be an incredible meeting place — a place that can, I think, transpose the best of our ideas in a much more effective way than before,” Bulović says. “I’m extremely excited about that.”

      Palacios notes that while microelectronics is best known for work making transistors smaller to fit on microprocessors, it’s a vast field that enables virtually all the technology around us, from wireless communications and high-speed internet to energy management, personalized health care, and more.

      He says he’s personally excited to use the new machines to do research around power electronics and semiconductors, including exploring promising new materials like gallium nitride, which could dramatically improve the efficiency of electronic devices.

      Fulfilling a mission

      MIT.nano’s leaders say a key driver of commercialization will be startups, both from MIT and beyond.

      “This is not only going to help the MIT research community innovate faster, it’s also going to enable a new wave of entrepreneurship,” Palacios says. “We’re reducing the barriers for students, faculty, and other entrepreneurs to be able to take innovation and get it to market. That fits nicely with MIT’s mission of making the world a better place through technology. I cannot wait to see the amazing new inventions that our colleagues and students will come out with.”

      Bulović says the announcement aligns with the mission laid out by MIT’s leaders at MIT.nano’s inception.

      “We have the space in MIT.nano to accommodate these tools, we have the capabilities inside MIT.nano to manage their operation, and as a shared and open facility, we have methodologies by which we can welcome anyone from the region to use the tools,” Bulović says. “That is the vision MIT laid out as we were designing MIT.nano, and this announcement helps to fulfill that vision.” More