MIT researchers have now developed an electrochemical approach to promote hydrogen release from ammonia while simultaneously separating and concentrating the hydrogen into a high-purity stream. Their strategy, which uses electricity to speed up the extraction, reduces the temperature and energy required to recover hydrogen from ammonia and other hydrogen carriers.
In a new study, the researchers showed that their approach can generate highly concentrated, pure streams of hydrogen.
“We have shown the ability to use electrochemistry to drive thermodynamically uphill and kinetically difficult dehydrogenation reactions,” says Yogesh Surendranath, the Donner Professor of Science and a professor of chemistry and chemical engineering. “In this case, we studied the conversion of ammonia and a liquid organic molecule because of their importance as possible hydrogen carriers for a hydrogen economy. But the concepts we learned here could in principle be translated further, and we’re actively working on translating it to other important dehydrogenation reactions.”
Surendranath is the corresponding author of the study, which appears today in Nature. MIT postdoc Rui Zeng, now a professor of materials science and engineering at Harbin Institute of Technology in Shenzhen, China, is the paper’s lead author.
Extracting hydrogen
Hydrogen is widely used in semiconductor manufacturing and chemical processing and is also an energy carrier in fuel cells that use hydrogen and oxygen to generate electricity without combustion. Expanding its use, however, will require practical ways to store and distribute it.
Hydrogen gas itself is difficult to transport efficiently without compression or liquefaction. One alternative is to store hydrogen chemically in compounds that are liquids or can be readily liquefied, then release it where and when it is needed.
Ammonia is one promising hydrogen carrier because it is already produced and transported across large distances, but recovering hydrogen from ammonia remains challenging. That process, known as “cracking,” requires temperatures higher than 500 degrees Celsius to achieve high reaction rates and conversion. The hydrogen must then be separated from nitrogen and unreacted ammonia.
“We wanted to ask whether we could use electrical inputs to drive what would otherwise be an unfavorable dehydrogenation reaction, and simultaneously do it in a way that would separate the hydrogen from the hydrogen carrier, so that it would be very pure and could be used directly in a fuel cell or other application that requires a high purity hydrogen stream,” Surendranath says.
The key element of the researchers’ new design is the coupling of a palladium-based separation membrane with a hydrogen-generating electrode through a molten hydroxide electrolyte. The separation membrane selectively transports hydrogen while preventing other components of the reaction mixture from passing through.
Using the new setup, ammonia is first dehydrogenated by a catalyst containing ruthenium and cesium. The hydrogen then reaches the separation membrane, whose opposite side is in contact with a molten hydroxide electrolyte.
The electrochemical gradient across this membrane effectively creates a “vacuum” for hydrogen, providing a strong driving force for its transport across the membrane. It also converts the hydrogen into protons and electrons, which travel separately through the molten electrolyte and external circuit, respectively, before recombining at a second electrode to form hydrogen gas.
Because the membrane selectively transports hydrogen, the system produces a concentrated stream of hydrogen gas without requiring a separate downstream purification process.
“Using this electrochemical process, we’re able to do this active pumping of hydrogen from a low concentration to a high concentration,” Surendranath says.
Continuously extracting hydrogen can also help drive the dehydrogenation reaction forward, especially when the presence of hydrogen inhibits the reaction. In this way, this strategy does more than separate the product: It changes the reaction environment and enables hydrogen recovery under milder conditions.
This process thus can be performed at temperatures around 200 or 300 degrees Celsius, much lower than those required for conventional ammonia cracking. Another advantage is that it creates a pure stream of hydrogen that doesn’t need to be purified later on — a step that requires additional energy.
Curtis Berlinguette, a professor of chemistry and chemical and biological engineering at the University of British Columbia, described the method as “a powerful new way” to solve the problem of obtaining a pure stream of hydrogen from ammonia and other hydrogen carriers.
“By using electricity to pull hydrogen through the membrane as it is released, they accelerate the dehydrogenation of ammonia and liquid organic hydrogen carriers while simultaneously producing a purified hydrogen stream. This is an important advance for the energy sciences because it opens a credible pathway for transporting hydrogen in stable chemical carriers and releasing it where and when it is needed,” says Berlinguette, who was not involved in the research.
Powering transportation
In this study, the researchers showed that this approach could be used to dehydrogenate not only ammonia but also methylcyclohexane. This molecule is part of a class known as liquid organic hydrogen carriers (LOHCs), which also hold potential as an energy carrier.
The researchers envision that their new strategy could be useful for transportation applications, such as powering cars, buses, or ships, or for fabricating semiconductors or electronics. Pure hydrogen gas is used for several steps in semiconductor manufacturing, where it plays important roles in boosting manufacturing yields and reducing surface defects.
Because palladium is an expensive metal, the researchers are now working on ways to reduce the amount of palladium needed for the separation membrane. They are also working on scaling up the process, and on applying it to other dehydrogenation reactions that could be industrially useful.
The research was funded by the U.S. National Science Foundation.
]]>“I like chemistry because I feel that the subject applies to everyday life,” said Jordan. “I want to make a positive impact on others through my research, and I thought that pursuing a PhD in chemistry would enable me to do this. What I enjoy most about my project is that I can directly apply my work to drug discovery, and I hope the science I am developing now will one day lead to a new class of medicines.”
As the subject of this Graduate Student Spotlight, Jordan shares something that was common in his childhood but will seem strange to future generations, the most famous people he’s met, the funniest show he’s seen, and more.
One reason for the translation gap is that current models don’t reliably factor in the chemical stability of the materials they generate, and unstable materials aren’t very useful in the real world. That forces industries to allocate huge computational budgets to screening out all the unstable materials they generate, in some cases leaving behind a tiny fraction of usable options.
Now, MIT researchers have developed a framework that can be applied at the beginning of the materials generation process to vastly improve the stability rate while achieving targeted material properties. It works by ensuring every design satisfies certain key rules of chemistry relating to the electrons around the materials’ atoms before the expensive generation step begins. The researchers call their approach “crystal generator with valence-constrained design, or CrysVCD.
In a paper published today in Nature Computational Science, the researchers show how CrysVCD allowed several commonly used material models to meet those valence shell rules more often, and used it to achieve high lattice-dynamics stability — a stringent stability test — in nearly 70 percent of computational material generations. They also showed the approach could support the creation of materials with specific desired properties, like high thermal conductivity or high dielectric constant, which is important for computer chips and data centers.
A hint of how the researchers envision people using their system is in the name.
“If material-generating models are like DVDs, we are like the DVD player,” says associate professor of nuclear science and engineering Mingda Li. “You can plug this into any kind of model, not only existing diffusion models but also future models, where people can’t generate enough stable materials, and it can improve stability.”
Joining Li on the paper are Mouyang Cheng SM ’26 and Weiliang Luo, MIT doctoral students in materials science and engineering and chemistry, respectively; Hao Tang PhD ’26, a recent graduate in materials science and engineering; Bowen Yu, a senior undergraduate in physics; Yongqiang Cheng, a staff scientist at the Oak Ridge National Laboratory; Weiwei Xie, an associate professor at Michigan State University; Ju Li, MIT’s Carl Richard Soderberg Professor in Power Engineering; and Heather Kulik, MIT’s Lammot du Pont Professor of Chemical Engineering.
More efficient materials
Computational approaches to materials design have been around for decades, but recent advances in artificial intelligence have increased excitement about their potential. Of particular interest are models that can start with a desired material property and work backward to deliver a material that achieves that goal.
Some of those models use an AI technique known as diffusion, which is commonly used to generate images, while others use large language models like the one powering ChatGPT and Claude, but both approaches struggle to ensure their material generations achieve chemical stability or follow fundamental principles about how chemicals interact and behave.
The solution has been to add another layer of computing on top of the generative process to filter out unstable materials.
“It’s becoming easy to generate the material structure,” Cheng says. “But the validation process, especially the part where you test the stability, has a huge computational cost. It’s something like 90 percent of the computational cost for creating usable materials, and it can take weeks or months.”
Big companies with huge computing budgets can afford to run those processes, but many small companies and research labs can’t, potentially limiting innovation in the field.
“In academia, where we have fewer resources, I think we can still achieve strong performance with smarter designs and other approaches,” Kulik explains. “Generating a model and then down-selecting for stability is inefficient. There’s a high computational cost. But if we put a language model in the beginning of the process to constrain the generation, you can significantly enhance the ratio of stable materials generated.”
The new study involved MIT researchers affiliated with the departments of Materials Science and Engineering, Chemistry, Chemical Engineering, Physics, and Nuclear Science and Engineering. Together the researchers combined AI diffusion models with a language model. In the first stage of their process, the language model produces chemically valid formulas. In the second stage, the diffusion model uses that formula to generate the corresponding atomic structure of the crystal material in coordination with the underlying material generation model.
“Diffusion for typical material generation is a slow process — you can think of it like 1,000 steps to create one material,” Luo says.
“In contrast, when our model is used in the beginning, you can think of it like five steps. It allows you to screen out the unstable materials to generate higher quality materials. And it works with any models generating materials,” Tang adds.
The researchers showed their approach created more stable materials an order of magnitude more efficiently than approaches that rely on screening materials after they’re generated. When fine-tuned on stability metrics, their approach produced crystalline materials that achieved 68 percent mechanical stability and 85 percent metastability, which measures if a material stays in a stable state when undisturbed.
The researchers then used their approach to generate material candidates with high thermal conductivity and easy polarization in an electric field.
“These are materials useful for the semiconductor industry and high thermal conductivity materials relevant to data center cooling,” Ju Li says. “In principle, you could also use this to create other properties, but thermal conductivity has become really important for cooling data centers. There’s been a huge increase in energy use in that industry, and 30 percent of that energy goes to cooling. The industry needs materials with high thermal conductivity to more efficiently remove the heat.”
Democratizing material design
The new approach doesn’t work with every kind of material — it works best with solid structures with highly ordered internal arrangements. Still, the approach could be used to generate stable new crystalline materials with a host of important properties.
“We are not just generating stable materials, we’re also prioritizing performance,” Cheng says. “Any time you have two goals, achieving those goals with anything over 50 percent is hard in this field. In the past, people might have a goal for specific properties and not stability, or vice-versa, and get a single-digit percentage of materials that fit their goal.”
Ultimately the approach will enable more researchers to develop novel materials for a range of next-generation applications.
“This will save huge computation costs and time by removing downstream selection requirements,” Li says. “That will help not only large efforts that generate hundreds of millions of materials, but also smaller research groups with targeted applications.”
The work was supported, in part, by the U.S. Department of Energy, a Mathworks Engineering Fellowship, the National Science Foundation, and the U.S. Defense Threat Reduction Agency.
]]>The Massachusetts Institute of Technology Department of Chemistry located at 77 Massachusetts Avenue, Cambridge, MA 02139 invites applications for a tenure-track position at the assistant professor level beginning July 1, 2027 or thereafter. Outstanding applicants with research interests in all areas of chemistry, broadly defined, are encouraged to apply. Faculty duties include classroom teaching in Chemistry at the undergraduate and graduate levels. Appointments are at the rank of assistant professor, but outstanding senior applicants may be considered. Applicants must hold a Ph.D. in chemistry or a related field by the start of employment and must demonstrate ability to excel in teaching.
The Department of Chemistry provides a welcoming and supportive environment for exceptional science, teaching, mentorship, and service. We seek candidates who embody our core values of respect, well-being, inclusivity, and integrity. We believe that education and research are at their finest when they include and appreciate the experiences of people of all backgrounds.
Required application materials include: CV, teaching statement, three research proposals, an executive summary of research plans, a broader impacts statement (which can cover topics related to teaching and educational efforts, mentoring, outreach, and/or service to the community), and at least three outside letters of recommendation.
Applications are being accepted at Academic Jobs Online.
To receive full consideration, completed applications must be received by October 1, 2026.
Pay range for a 9-month academic appointment at the Assistant Professor rank: $143,200 – $154,000.
MIT provides pay ranges representing its good faith estimate of what the Institute reasonably expects to pay for a position at the time of posting. The pay offered to a selected candidate during hiring will be based on factors such as (but not limited to) the scope and responsibilities of the position, the candidate’s work experience and education/training, internal peer equity, and applicable legal requirements. This pay range represents base pay only and does not include any other benefits or compensation.
MIT is an equal opportunity employer. We strongly encourage applications from individuals from all identities and backgrounds. All qualified applicants will receive equitable consideration for employment based on their experience and qualifications and will not be discriminated against on the basis of race, color, sex, sexual orientation, gender identity, pregnancy, religion, disability, age, genetic information, veteran status, or national or ethnic origin. View MIT Policy on Non Discrimination and EEOC’s Know Your Rights. Employment is contingent upon the completion of a satisfactory background check, including possible verification of any findings of misconduct (or pending investigations) from prior employers.
]]>Abigail Chapman
Xinnuo Chen
Martin Chujfi
Cole English
Amanda Gin
Tierani Green
Stephanie Halim
Yuxin Huang
Constantine Kyprianou
Chu Luo
Alvin Meng
Micah Miles
Alexander Mueller
Kiarra Ning
Matthew Ong
Diana Tymochko
August Vitarbo
Dalaney Westbroek
Luke Zhou
Sunny Tang
Dr. Gabi Wenzel
Dr. Shuo Zhang
Dr. Saptarshi Mandal
Dr. Jonas Rein
Minsik Cho
Kwangwook Ko
Dangliang Liu
Chonghe Zhang
Dr. Aditi Dixit
Nina Greeley
Dr. Kubra Kaygisiz
Carina Luo
Omar Salinas
Jennifer Pierre-Louis
]]>Wang joined the Department of Chemistry and the Broad Institute in 2019 and earned tenure in 2024. As the recipient of the Eli Lilly Award, she will be honored as the featured speaker at a symposium held during the Spring 2027 ACS National Meeting.
The Wang Lab develops and applies state-of-the-art tools across chemistry, biophysics, and genomics to map the brain from molecules to systems. Specifically, using in situ sequencing of nucleic acids as a core approach, Wang aims to develop high-resolution, highly multiplexed molecular imaging methods across multiple scales to better understand the physical and chemical basis of brain wiring and function.
]]>Radosevich, who joined the Department of Chemistry in 2016, was honored for discovering new reaction pathways and organocatalysts featuring biphilic phosphorus (P) compounds that operate through P(III)/P(V) redox cycling. Research in the Radosevich group centers on inventing new homogeneous catalysts and reagents derived from inexpensive, earth-abundant p-block elements.
Wendlandt joined the Department of Chemistry in 2018 and was honored for developing light-driven methods for stereochemical editing and their synthetic applications. Her research focuses on developing selective, catalytic reactions using the tools of organic and organometallic synthesis alongside physical organic chemistry.
Recipients of the Arthur C. Cope Scholar Awards will be honored at the Fall 2026 meeting of the American Chemical Society.
]]>The traditional way of making ammonia, in use for more than a century and accounting for the vast majority of production, is the Haber-Bosch process, which relies on fossil fuels to provide the needed heat. Hydrogen used in the process is also largely produced from fossil fuels.
There is another way, using electrochemistry instead of heat and pressure, but so far this method has not been anywhere near economically competitive at the scales needed.
Now, researchers at MIT have developed a way to predict which materials could be most promising as catalysts in electrochemical ammonia production. Catalysts help drive chemical reactions, and their properties determine how efficiently those reactions proceed. Rather than using trial and error to test each possible combination out of the millions of possible alloys — which can take years — the new approach could greatly speed up the search for materials that could make this low-emissions method competitive with the Haber-Bosch process.
“Our approach identifies the key physical properties that drive catalytic activity in ammonia production,” says Bilge Yildiz, the Breen M. Kerr Professor in the departments of Nuclear Science and Engineering and Materials Science and Engineering (DMSE). The results can guide the search for new and more effective catalyst compounds.
The open-access findings were published Aug. 11 in the Royal Society of Chemistry journal EES Catalysis, in a paper by Yildiz and doctoral students Constantine Athanitis of DMSE and Filip Grajkowski of the Department of Chemistry.
The challenge of greener ammonia
As the world’s population grows, Athanitis says, “we’re just going to need more and more food, and the only reason why we’re able to sustain so many people is because of fertilizer.” But more than 90 percent of the ammonia needed for fertilizer is still made by that energy-intensive Haber-Bosch process, which “has been hyper-optimized since it first came out more than a century ago,” he says.
“If we’re trying to keep in line with society’s sustainability and energy targets and climate change targets, we really need to come up with another alternative,” he explains. The world currently uses about 200 million metric tons of ammonia each year, “so ideally we want to be able to find a way to produce the same amount of ammonia, or even more, but in a more energy-efficient way and also with lower CO2 emissions,” he says.
Using electricity to produce ammonia is not a new idea. “It’s really just the electrochemical reaction between proton-electron pairs and nitrogen gas. And these technologies exist,” he says. The approach uses the same basic principles as electrolyzers, which use electricity to drive chemical reactions in devices.
But while the process works, it’s not efficient enough for industrial-scale production. “Production rates and yields are still too low,” Athanitis says. “Even though a technology might be better for the world or for the climate, companies and capitalism won’t really allow it unless it’s cost competitive.”
How to make it more competitive? The key ingredient in the electrochemical process is a metallic catalyst, whose properties govern the reaction that takes place on its surface. “If we can somehow find a catalyst that reduces the energy needed and is more selective for ammonia production,” Athanitis says, “then we could essentially hit the jackpot.” A more selective catalyst would produce more ammonia while reducing unwanted side reactions.
Finding better catalysts
But finding that ideal catalyst is not simply a matter of identifying one perfect material. Different materials can improve different parts of the reaction, and researchers are seeking combinations that can make ammonia production efficient, affordable, and practical at large scale.
“Metal nitride compounds make an ideal material system for this reaction and for identifying the electronic, chemical, and structural properties that determine reactivity in nitrogen reduction and ammonia electrosynthesis,” Yildiz says.
Transition metals could form promising nitride alloys for this purpose, and historically, “materials research has been pretty much trial and error,” Athanitis says.
The usual process is to take some existing material and “tweak it in some way,” he says. “It’s all somewhat guided by scientific and chemical intuition.”
Now, increasingly, computational tools are being used to model the physical interactions and predict outcomes. A method called density functional theory uses quantum mechanics to simulate the properties and behavior of materials, allowing researchers to predict how different atomic arrangements may perform before making them in the lab. Rather than searching randomly through every possible alloy combination, Yildiz says, “we first assessed what microscopic properties of the material make them tick for nitrogen reduction.”
For ammonia-producing catalysts, “we’re looking at transition metal nitrides,” Athanitis says, because they have been found to be effective in these electrochemical nitrogen reactions. They are especially effective because “the nitrogen inherent to the catalyst itself becomes part of the reaction.”
This produces a series of chemical steps in which one step provides part of the energy needed to drive the next, reducing the amount of input energy needed. This helps solve one of the major bottlenecks in the nitrogen reduction reaction: the high energy required to break the strong bonds in nitrogen molecules, he says.
But the process is far from perfect, Athanitis says. It is “still limited by certain steps throughout the reaction pathway, including nitrogen dissociation and hydrogen transfer.” The study attempted to identify those bottlenecks and, with the help of machine learning, determine which alloys of these metals might overcome them.
With that understanding, “it can give us insights and open up potential strategies for how we can tune these materials to create next-generation better nitride catalysts,” Athanitis says.
Pushing past theory
The approach is “exciting work” that could help develop a foundation for designing new catalysts for ammonia production, says Dane Morgan, a professor of engineering at the University of Wisconsin who was not involved in this study.
“This work helps clarify how fundamental electronic properties of a material relate to its role as a catalyst in making ammonia,” Morgan says. “Such understanding can help guide researchers in designing new catalysts, both through better qualitative understanding and by accelerating computational screening.”
So far, the study is purely theoretical: The researchers have used computer models to identify promising alloys, but those materials still need to be made and tested. Morgan notes that “translating these calculations into practical catalysts will require many additional steps, so meaningful real-world impact is likely still some distance away.”
The next step will be to build a working reaction cell, a laboratory device that uses the catalyst to produce ammonia and test its performance under real operating conditions. “For this to really make an impact in society, we need to bring it to the experimental lab,” Athanitis says.
“There have always been pushes at the frontiers of what’s possible,” he adds. “We like to think we’ve pushed the boundary of candidate materials here beyond what was thought of before, and hopefully we’re almost there. But even if we’re not almost there, we’re still pushing in the right direction.”
]]>Expected to provide $18 million in research funding over six years, the award brings together 16 research groups from nine departments across four institutions, including five MIT departments, three collaborating universities, and a teaching hospital. The award is pending MIT’s negotiation of a formal research agreement with the NSF.
The MIT Materials Research Science and Engineering Center will be directed by Associate Professor Rafael Jaramillo of the Department of Materials Science and Engineering (DMSE), with Professor Caroline Ross of DMSE serving as associate director. The center will be housed administratively within the MIT Materials Research Laboratory.
The center will have two main research thrusts. One will engineer specialized materials to advance X-ray detectors used in medical imaging, potentially leading to better cancer diagnosis, lower radiation exposure, and improved industrial and security imaging. The other will explore high-temperature sulfur-based molten materials to transform how metals and semiconductors are made, opening a path to more efficient metal production, improved access to critical materials, and new thin-film semiconductor technologies.
The expected funding will also support a new shared laboratory for testing magnetic materials and materials under extreme conditions, managed by MIT.nano. This facility will be available to academic and industry users, expanding the nationwide portfolio of NSF-supported research facilities.
“The long-term goal is for the broader materials and engineering community to see the disruptive potential of bringing researchers together across disciplines to solve complex challenges,” says Jaramillo, the Stavros V. Salapatas Career Development Professor of Materials Science and Engineering. “And that includes specifically in medical diagnostics and metals production, where entirely new things will be possible that aren’t considered possible today.”
A legacy of collaboration
The selection of MIT’s MRSEC is part of a $108 million NSF investment in six research centers that will explore a range of topics, including artificial intelligence-driven experimental laboratories and hybrid quantum materials that combine light and matter. NSF’s MRSEC program brings together interdisciplinary teams of researchers to push the boundaries of materials science and engineering and tackle complex scientific challenges.
The MIT center builds on nearly 60 years of interdisciplinary materials research at the Institute, extending a legacy that began with U.S. Department of Defense-supported laboratories in the 1960s and continued through NSF-funded centers in subsequent decades. Past MRSEC investments helped build research communities that enabled MIT centers of excellence such as the MIT Microphotonics Center and the Microsystems Technology Laboratories.
“We were inspired to continue that legacy of collaborative research in materials science,” Jaramillo says. “It’s mainly the mode of working — the mode of working in a very intentional way as a team across disciplinary boundaries and having this program that brings people together.”
MIT departments involved in the MRSEC include DMSE; Chemistry; Chemical Engineering; Earth, Atmospheric and Planetary Sciences (EAPS); and Physics. Collaborating institutions identified in the MRSEC proposal are Yale University, the University of California at Santa Barbara, and the Department of Radiology at Massachusetts General Hospital and Harvard Medical School.
The first research group will focus on re-engineering scintillators — materials that convert X-rays into visible light — at the nanoscale, with the goal of improving resolution, speed, and energy sensitivity.
“My vision for that is really Marin and JJ’s vision. So I’m basically cheerleading for them,” Jaramillo says, referring to optical materials experts Professor Marin Soljačić of Physics and Professor Juejun Hu of DMSE, who are expected to lead the effort.
The second group is closer to Jaramillo’s own research in semiconductor and advanced electronic materials. It seeks to develop a deeper understanding of high-temperature sulfur-based liquids to improve the yield and efficiency of producing critical metals such as copper. Expertise in these types of materials has become increasingly rare in U.S. academia, Jaramillo says, and one goal of the center is to rebuild that capability at MIT. “I’m very excited about that being a new intellectual center of gravity.”
Telling stories about materials
Beyond research, the center is also expected to develop outreach activities highlighting the importance of materials science in society, particularly in the Boston region, where Jaramillo said industries need more workers with backgrounds in materials processing.
“For example, our community colleges don’t offer it,” Jaramillo says. “If you were looking at a community college in Michigan, everyone would know what materials science is.”
One initiative, DISASTER! — “with all caps and an exclamation mark,” Jaramillo says — will tell stories of real-world catastrophes and the materials failures that contributed to them.
A major part of materials science over the last century has been understanding why things fail, Jaramillo says. “It’s also a tremendous foot in the door for introducing the field. Because frankly, ‘if it bleeds, it leads.’ If you have giant disasters, then suddenly people are like, ‘Why did the bridge fail?’”
The program will encourage MIT undergraduates to research and tell these stories, illustrating how forensic materials science has helped prevent future failures.
Among the examples Jaramillo cited are the rivets used to assemble the RMS Titanic, whose impurities made the rivets more brittle in the freezing North Atlantic, and the crashes of the world’s first commercial jetliner, the de Havilland Comet, which revealed the dangers of metal fatigue.
“There are so many other stories that need to be told around how a material failed,” Jaramillo said. “It really cost people money and time and lives. And then through forensic materials science, we understood why it failed and we avoided future failures.”
The MRSEC team is planning to stage public outreach events at the MIT Future Fest.
Looking ahead six years, Jaramillo hopes the center will have become a self-sustaining hub for materials research.
“I hope that we will have rebuilt the muscle memory to come together in an interdisciplinary way around materials science, and that it should have a bit of a self-sustaining element to it. I hope that we then compete successfully for the next center, and lay the groundwork for the next 60 years.”
MIT Research Administration Services supported the MRSEC proposal development through its Research Development team, which specializes in providing substantive assistance for large and complex research proposals, and in supporting early-career faculty.
MIT faculty expected to be involved in the MRSEC are Rafael Jaramillo, Caroline Ross, Juejun Hu, and Antoine Allanore of DMSE; Moungi Bawendi of Chemistry; Martin Bazant of Chemical Engineering; Nicole Nie and Shuhei Ono of EAPS; and Marin Soljačić, Riccardo Comin, Nuh Gedik, and Long Ju of Physics.
]]>But integrating molecules into functional devices at scale remains a challenge. Traditional semiconductor manufacturing processes can damage small and fragile molecular materials. Now, MIT researchers have developed a scalable fabrication technique that incorporates delicate molecular materials into electronic devices on a chip without causing damage.
Their method extends the capabilities of standard semiconductor manufacturing processes to accommodate molecules. The researchers first prefabricate the device components using traditional processes. Then, they introduce the molecules and harness nanoscale surface forces to mechanically transform the fabricated device, which self-assembles without damaging the molecules.
The team demonstrated the robustness and scalability of their technique by fabricating more than 1,000 devices using sub-nanometer molecular layers.
“Our platform combines the scalability of conventional semiconductor manufacturing with the precision and control of self-assembly. This establishes a new fabrication framework for the scalable, high-throughput integration of emerging nanoscale and quantum materials, including molecules, into functional devices with architectures and capabilities that were previously infeasible,” says Farnaz Niroui, an associate professor of electrical engineering and computer science (EECS), a member of the Research Laboratory of Electronics (RLE), and senior author of a new paper describing the work.
She is joined on the paper by co-lead authors Sarah Spector and Peter Satterthwaite, EECS graduate students; Jeremiah A. Johnson, the A. Thomas Guertin Professor of Chemistry at MIT; and others at MIT. The research appears today in Nature Nanotechnology.
Building with molecules
Molecules are small clusters of atoms with structures and chemistries that can be precisely designed. This allows their properties to be engineered across a wide design space.
Once integrated into device architectures, these molecules could enable next-generation electronics and computing platforms that are smaller, faster, and more adaptable, as well as higher-performance photonic devices and emerging quantum technologies.
To build a functional system, molecular building blocks need to be integrated with other device layers. In electronic systems, a critical step is making electrical contacts to the molecules by interfacing them with metallic surfaces. However, the harsh chemicals and processes needed for traditional chip manufacturing damages these fragile molecular materials, reducing reliability and performance.
To leverage the scalability of standard fabrication techniques while achieving the precision needed for handling molecules, the MIT researchers developed a decoupled, two-step approach.
They first fabricate all the device components using standard semiconductor manufacturing, then incorporate the molecular material after-the-fact to finish building the device.
“By bringing the delicate materials into the process only after we have fabricated the main device elements, it allows us to use conventional processes that are normally not compatible with these nanomaterials,” Satterthwaite says.
In their demonstration, the researchers fabricated a scaffold with two metal electrodes separated by a precisely sized gap. Then, they deposited the molecular layer on the electrode surfaces.
Finally, the researchers leverage nanoscale forces to gently pull the top electrode onto the molecules, forming the final device in a nondestructive way. This creates a self-aligned, damage-free electrical contact to the molecules.
Using the forces
While gravity is a dominant physical force that holds our world together, different forces dominate at the nanoscale. One, called the capillary force, causes liquid to get sucked into small spaces. (Plants rely on capillary forces to draw water into their stems.)
By carefully engineering the stiffness of the electrodes, when the solution containing the molecules evaporates, capillary forces gently pull the two metal surfaces together with the molecules sandwiched in between.
Once the two electrodes are in place, the researchers must hold them in a stable state. To do so, they rely on another nanoscale force known as the van der Waals force.
Van der Waals forces cause surfaces to attract one another. By controlling the device surface area and molecules properties, the researchers ensure these forces will be strong enough to hold the electrodes in a stable structure without damaging the molecules.
“Nanoscale forces play a critical role in our approach. Instead of fabricating exactly the structures we ultimately want, we make something mechanically mobile and use forces to transform it into an architecture that would otherwise be impossible to fabricate,” Spector explains.
They used this technique to fabricate more than 1,000 devices with molecular layers less than 1 nanometer thick. Even at this tiny scale, the fabricated chips comprised a high yield of working devices, 96 percent on average. The robust devices also endured tens of thousands of electrical cycles without showing any sign of degradation.
“The stability really stands out. This is a critical feature for moving molecular devices toward practical applications, but it has been a persistent challenge in the field,” Satterthwaite says.
Importantly, this versatile technique allows circuit- and system-level integration of molecular devices, pushing the field beyond the study of isolated devices, the researchers say. They demonstrated this by building an interconnected array of molecular memory devices which could have applications in next-generation computing platforms.
Their technique can also be extended to other materials and device architectures.
In the future, the researchers want to build on this platform to investigate and develop new classes of multifunctional computing and sensing devices and systems.
“By enabling the pristine integration of emerging molecular materials and other atomic-scale matter into functional devices at scale, our platform accelerates discovery and design of these materials with tailored functionalities and their deployment in emerging technologies,” Niroui adds.
This research was funded, in part, by the U.S. Defense Advanced Research Projects Agency (DARPA), the Semiconductor Research Corporation, the U.S. National Science Foundation (NSF), the MathWorks Fellowship, and the Netherlands Organization for Scientific Research. Device fabrication was carried out, in part, using MIT.nano facilities.
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