Nature Climate Change, Published online: 23 June 2025; doi:10.1038/s41558-025-02378-y

Author Correction: Recommendations for producing knowledge syntheses to inform climate change assessments

This is the first ever video of the Antarctic Gonate Squid.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Launched in February of this year, the MIT Generative AI Impact Consortium (MGAIC), a presidential initiative led by MIT’s Office of Innovation and Strategy and administered by the MIT Stephen A. Schwarzman College of Computing, issued a call for proposals, inviting researchers from across MIT to submit ideas for innovative projects studying high-impact uses of generative AI models.

The call received 180 submissions from nearly 250 faculty members, spanning all of MIT’s five schools and the college. The overwhelming response across the Institute exemplifies the growing interest in AI and follows in the wake of MIT’s Generative AI Week and call for impact papers. Fifty-five proposals were selected for MGAIC’s inaugural seed grants, with several more selected to be funded by the consortium’s founding company members.

Over 30 funding recipients presented their proposals to the greater MIT community at a kickoff event on May 13. Anantha P. Chandrakasan, chief innovation and strategy officer and dean of the School of Engineering who is head of the consortium, welcomed the attendees and thanked the consortium’s founding industry members.

“The amazing response to our call for proposals is an incredible testament to the energy and creativity that MGAIC has sparked at MIT. We are especially grateful to our founding members, whose support and vision helped bring this endeavor to life,” adds Chandrakasan. “One of the things that has been most remarkable about MGAIC is that this is a truly cross-Institute initiative. Deans from all five schools and the college collaborated in shaping and implementing it.”

Vivek F. Farias, the Patrick J. McGovern (1959) Professor at the MIT Sloan School of Management and co-faculty director of the consortium with Tim Kraska, associate professor of electrical engineering and computer science in the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), emceed the afternoon of five-minute lightning presentations.

Presentation highlights include:

“AI-Driven Tutors and Open Datasets for Early Literacy Education,” presented by Ola Ozernov-Palchik, a research scientist at the McGovern Institute for Brain Research, proposed a refinement for AI-tutors for pK-7 students to potentially decrease literacy disparities.

“Developing jam_bots: Real-Time Collaborative Agents for Live Human-AI Musical Improvisation,” presented by Anna Huang, assistant professor of music and assistant professor of electrical engineering and computer science, and Joe Paradiso, the Alexander W. Dreyfoos (1954) Professor in Media Arts and Sciences at the MIT Media Lab, aims to enhance human-AI musical collaboration in real-time for live concert improvisation.

“GENIUS: GENerative Intelligence for Urban Sustainability,” presented by Norhan Bayomi, a postdoc at the MIT Environmental Solutions Initiative and a research assistant in the Urban Metabolism Group, which aims to address the critical gap of a standardized approach in evaluating and benchmarking cities’ climate policies.

Georgia Perakis, the John C Head III Dean (Interim) of the MIT Sloan School of Management and professor of operations management, operations research, and statistics, who serves as co-chair of the GenAI Dean’s oversight group with Dan Huttenlocher, dean of the MIT Schwarzman College of Computing, ended the event with closing remarks that emphasized “the readiness and eagerness of our community to lead in this space.”

“This is only the beginning,” he continued. “We are at the front edge of a historic moment — one where MIT has the opportunity, and the responsibility, to shape the future of generative AI with purpose, with excellence, and with care.”

The open space connecting Hockfield Court with Massachusetts Avenue, in the heart of MIT’s campus, is now the L. Rafael Reif Innovation Corridor, in honor of the Institute’s 17th president. At a dedication ceremony Monday, Reif’s colleagues, friends, and family gathered to honor his legacy and unveil a marker for the walkway that was previously known as North Corridor or “the Outfinite.”

“It’s no accident that the space we dedicate today is not a courtyard, but a corridor — a channel for people and ideas to flow freely through the heart of MIT, and to carry us outward, to limits of our aspirations,” said Sally Kornbluth, who succeeded Reif as MIT president in 2023.

“With his signature combination of new-world thinking and old-world charm, and as a grand thinker and doer, Rafael left an indelible mark on MIT,” Kornbluth said. “As a permanent testament to his service and his achievements in service to MIT, the nation, and the world, we now dedicate this space as the L. Rafael Reif Innovation Corridor.”

Reif served as president for more than 10 years, following seven years as provost. He has been at MIT since 1980, when he joined the faculty as an assistant professor of electrical engineering.

“Through all those roles, what stood out most was his humility, his curiosity, and his remarkable ability to speak with clarity and conviction,” said Corporation Chair Mark Gorenberg, who opened the ceremony. “Under his leadership, MIT not only stayed true to its mission, it thrived, expanding its impact and strengthening its global voice.”

Gorenberg introduced Abraham J. Siegel Professor of Management and professor of operations research Cindy Barnhart, who served as chancellor, then provost, during Reif’s term as president. Barnhart, who will be stepping down as provost on July 1, summarized the many highlights from Reif’s presidency, such as the establishment of MIT Schwarzman College of Computing, the revitalization of Kendall Square, and the launch of The Engine, as well as the construction or modernization of many buildings, from the Wright Brothers Wind Tunnel to the new Edward and Joyce Linde Music Building, among other accomplishments.

“Beyond space, Rafael’s bold thinking and passion extends to MIT’s approach to education,” Barnhart continued, describing how Reif championed the building of OpenCourseWare, MITx, and edX. She also noted his support for the health and well-being of the MIT community, through efforts such as addressing student sexual misconduct and forming the MindHandHeart initiative. He also hosted dance parties and socials, joined students in the dining halls for dinner, chatted with faculty and staff over breakfasts and at forums, and more.

“At gatherings over the years, Rafael’s wife, Chris, was there by his side,” Barnhart noted, adding, “I’d like to take this opportunity to acknowledge her and thank her for her welcoming and gracious spirit.”

In summary, “I am grateful to Rafael for his visionary leadership and for his love of MIT and its people,” Barnhart said as she presented Reif with a 3D-printed replica of the Maclaurin buildings (MIT Buildings 3, 4, and 10), which was created through a collaboration between the Glass Lab, Edgerton Center, and Project Manus.

Next, Institute Professor Emeritus John Harbison played an interlude on the piano, and a musical ensemble reprised the “Rhumba for Rafael,” which Harbison composed for Reif’s inauguration in 2012.

When Reif took the podium, he reflected on the location of the corridor and its significance to early chapters in his own career; his first office and lab were in Building 13, overlooking what is now the eponymous walkway.

He also considered the years ahead: “The people who pass through this corridor in the future will surely experience the unparalleled excitement of being young at MIT, with the full expectation of upending the world to improve it,” he said.

Faculty and staff walking through the corridor may experience the “undimmed excitement” of working and studying alongside extraordinary students and colleagues, and feeling the “deep satisfaction of having created infinite memories here throughout a long career.”

“Even if none of them gives me a thought,” Reif continued, “I would like to believe that my spirit will be here, watching them with pride as they continue the never-ending mission of creating a better world.”

Researchers recently caught Meta using an egregious new tracking technique to spy on you. Exploiting a technical loophole, the company was able to have their apps snoop on users’ web browsing. This tracking technique stands out for its flagrant disregard of core security protections built into phones and browsers. The episode is yet another reason to distrust Meta, block web tracking, and end surveillance advertising. 

Fortunately, there are steps that you, your browser, and your government can take to fight online tracking. 

What Makes Meta’s New Tracking Technique So Problematic?

More than 10 years ago, Meta introduced a snippet of code called the “Meta pixel,” which has since been embedded on about 20% of the most trafficked websites. This pixel exists to spy on you, recording how visitors use a website and respond to ads, and siphoning potentially sensitive info like financial information from tax filing websites and medical information from hospital websites, all in service of the company’s creepy system of surveillance-based advertising. 

While these pixels are well-known, and can be blocked by tools like EFF’s Privacy Badger, researchers discovered another way these pixels were being used to track you. 

Even users who blocked or cleared cookies, hid their IP address with a VPN, or browsed in incognito mode could be identified

Meta’s tracking pixel was secretly communicating with Meta’s apps on Android devices. This violates a fundamental security feature (“sandboxing”) of mobile operating systems that prevents apps from communicating with each other. Meta got around this restriction by exploiting localhost, a feature meant for developer testing. This allowed Meta to create a hidden channel between mobile browser apps and its own apps. You can read more about the technical details here.

This workaround helped Meta bypass user privacy protections and attempts at anonymity. Typically, Meta tries to link data from “anonymous” website visitors to individual Meta accounts using signals like IP addresses and cookies. But Meta made re-identification trivial with this new tracking technique by sending information directly from its pixel to Meta's apps, where users are already logged in. Even users who blocked or cleared cookies, hid their IP address with a VPN, or browsed in incognito mode could be identified with this tracking technique.  

Meta didn’t just hide this tracking technique from users. Developers who embedded Meta’s tracking pixels on their websites were also kept in the dark. Some developers noticed the pixel contacting localhost from their websites, but got no explanation when they raised concerns to Meta. Once publicly exposed, Meta immediately paused this tracking technique. They claimed they were in discussions with Google about “a potential miscommunication regarding the application of their policies.”

While the researchers only observed the practice on Android devices, similar exploits may be possible on iPhones as well.

This exploit underscores the unique privacy risks we face when Big Tech can leverage out of control online tracking to profit from our personal data.

How Can You Protect Yourself?

Meta seems to have stopped using this technique for now, but that doesn’t mean they’re done inventing new ways to track you. Here are a few steps you can take to protect yourself:

Use a Privacy-Focused Browser

Choose a browser with better default privacy protections than Chrome. For example, Brave and DuckDuckGo protected users from this tracking technique because they block Meta’s tracking pixel by default. Firefox only partially blocked the new tracking technique with its default settings, but fully blocked it for users with “Enhanced Tracking Protection” set to “Strict.” 

It’s also a good idea to avoid using in-app browsers. When you open links inside the Facebook or Instagram apps, Meta can track you more easily than if you opened the same links in an external browser.

Delete Unnecessary Apps

Reduce the number of ways your information can leak by deleting apps you don’t trust or don’t regularly use. Try opting for websites over apps when possible. In this case, and many similar cases, using the Facebook and Instagram website instead of the apps would have limited data collection. Even though both can contain tracking code, apps can access information that websites generally can’t, like a persistent “advertising ID” that companies use to track you (follow EFF’s instructions to turn it off if you haven’t already). 

Install Privacy Badger

EFF’s free browser extension blocks trackers to stop companies from spying on you online. Although Privacy Badger would’ve stopped Meta’s latest tracking technique by blocking their pixel, Firefox for Android is the only mobile browser it currently supports. You can install Privacy Badger on Chrome, Firefox, and Edge on your desktop computer. 

Limit Meta’s Use of Your Data

Meta’s business model creates an incentive to collect as much information as possible about people to sell targeted ads. Short of deleting your accounts, you have a number of options to limit tracking and how the company uses your data.

How Should Google Chrome Respond?

After learning about Meta’s latest tracking technique, Chrome and Firefox released fixes for the technical loopholes that Meta exploited. That’s an important step, but Meta’s deliberate attempt to bypass browsers’ privacy protections shows why browsers should do more to protect users from online trackers. 

Unfortunately, the most popular browser, Google Chrome, is also the worst for your privacy. Privacy Badger can help by blocking trackers on desktop Chrome, but Chrome for Android doesn’t support browser extensions. That seems to be Google’s choice, rather than a technical limitation. Given the lack of privacy protections they offer, Chrome should support extensions on Android to let users protect themselves. 

Although Chrome addressed the latest Meta exploit after it was exposed, their refusal to block third-party cookies or known trackers leaves the door wide open for Meta’s other creepy tracking techniques. Even when browsers block third-party cookies, allowing trackers to load at all gives them other ways to harvest and de-anonymize users’ data. Chrome should protect its users by blocking known trackers (including Google’s). Tracker-blocking features in Safari and Firefox show that similar protections are possible and long overdue in Chrome. It has yet to be approved to ship in Chrome, but a Google proposal to block fingerprinting scripts in Incognito Mode is a promising start. 

Yet Another Reason to Ban Online Behavioral Advertising

Meta’s business model relies on collecting as much information as possible about people in order to sell highly-targeted ads. Even if this method has been paused, as long as they have the incentive to do so Meta will keep finding ways to bypass your privacy protections. 

The best way to stop this cycle of invasive tracking techniques and patchwork fixes is to ban online behavioral advertising. This would end the practice of targeting ads based on your online activity, removing the primary incentive for companies to track and share your personal data. We need strong federal privacy laws to ensure that you, not Meta, control what information you share online.

Volcanic islands, such as the islands of Hawaii and the Caribbean, are surrounded by coral reefs that encircle an island in a labyrinthine, living ring. A coral reef is punctured at points by reef passes — wide channels that cut through the coral and serve as conduits for ocean water and nutrients to filter in and out. These watery passageways provide circulation throughout a reef, helping to maintain the health of corals by flushing out freshwater and transporting key nutrients.

Now, MIT scientists have found that reef passes are shaped by island rivers. In a study appearing today in the journal Geophysical Research Letters, the team shows that the locations of reef passes along coral reefs line up with where rivers funnel out from an island’s coast.

Their findings provide the first quantitative evidence of rivers forming reef passes.  Scientists and explorers had speculated that this may be the case: Where a river on a volcanic island meets the coast, the freshwater and sediment it carries flows toward the reef, where a strong enough flow can tunnel into the surrounding coral. This idea has been proposed from time to time but never quantitatively tested, until now.

“The results of this study help us to understand how the health of coral reefs depends on the islands they surround,” says study author Taylor Perron, the Cecil and Ida Green Professor of Earth, Atmospheric and Planetary Sciences at MIT.

“A lot of discussion around rivers and their impact on reefs today has been negative because of human impact and the effects of agricultural practices,” adds lead author Megan Gillen, a graduate student in the MIT-WHOI Joint Program in Oceanography. “This study shows the potential long-term benefits rivers can have on reefs, which I hope reshapes the paradigm and highlights the natural state of rivers interacting with reefs.”

The study’s other co-author is Andrew Ashton of the Woods Hole Oceanographic Institution.

Drawing the lines

The new study is based on the team’s analysis of the Society Islands, a chain of islands in the South Pacific Ocean that includes Tahiti and Bora Bora. Gillen, who joined the MIT-WHOI program in 2020, was interested in exploring connections between coral reefs and the islands they surround. With limited options for on-site work during the Covid-19 pandemic, she and Perron looked to see what they could learn through satellite images and maps of island topography. They did a quick search using Google Earth and zeroed in on the Society Islands for their uniquely visible reef and island features.

“The islands in this chain have these iconic, beautiful reefs, and we kept noticing these reef passes that seemed to align with deeply embayed portions of the coastline,” Gillen says. “We started asking ourselves, is there a correlation here?”

Viewed from above, the coral reefs that circle some islands bear what look to be notches, like cracks that run straight through a ring. These breaks in the coral are reef passes — large channels that run tens of meters deep and can be wide enough for some boats to pass through. On first look, Gillen noticed that the most obvious reef passes seemed to line up with flooded river valleys — depressions in the coastline that have been eroded over time by island rivers that flow toward the ocean. She wondered whether and to what extent island rivers might shape reef passes.

“People have examined the flow through reef passes to understand how ocean waves and seawater circulate in and out of lagoons, but there have been no claims of how these passes are formed,” Gillen says. “Reef pass formation has been mentioned infrequently in the literature, and people haven’t explored it in depth.”

Reefs unraveled

To get a detailed view of the topography in and around the Society Islands, the team used data from the NASA Shuttle Radar Topography Mission — two radar antennae that flew aboard the space shuttle in 1999 and measured the topography across 80 percent of the Earth’s surface.

The researchers used the mission’s topographic data in the Society Islands to create a map of every drainage basin along the coast of each island, to get an idea of where major rivers flow or once flowed. They also marked the locations of every reef pass in the surrounding coral reefs. They then essentially “unraveled” each island’s coastline and reef into a straight line, and compared the locations of basins versus reef passes.

“Looking at the unwrapped shorelines, we find a significant correlation in the spatial relationship between these big river basins and where the passes line up,” Gillen says. “So we can say that statistically, the alignment of reef passes and large rivers does not seem random. The big rivers have a role in forming passes.”

As for how rivers shape the coral conduits, the team has two ideas, which they call, respectively, reef incision and reef encroachment. In reef incision, they propose that reef passes can form in times when the sea level is relatively low, such that the reef is exposed above the sea surface and a river can flow directly over the reef. The water and sediment carried by the river can then erode the coral, progressively carving a path through the reef.

When sea level is relatively higher, the team suspects a reef pass can still form, through reef encroachment. Coral reefs naturally live close to the water surface, where there is light and opportunity for photosynthesis. When sea levels rise, corals naturally grow upward and inward toward an island, to try to “catch up” to the water line.

“Reefs migrate toward the islands as sea levels rise, trying to keep pace with changing average sea level,” Gillen says.

However, part of the encroaching reef can end up in old river channels that were previously carved out by large rivers and that are lower than the rest of the island coastline. The corals in these river beds end up deeper than light can extend into the water column, and inevitably drown, leaving a gap in the form of a reef pass.

“We don’t think it’s an either/or situation,” Gillen says. “Reef incision occurs when sea levels fall, and reef encroachment happens when sea levels rise. Both mechanisms, occurring over dozens of cycles of sea-level rise and island evolution, are likely responsible for the formation and maintenance of reef passes over time.”

The team also looked to see whether there were differences in reef passes in older versus younger islands. They observed that younger islands were surrounded by more reef passes that were spaced closer together, versus older islands that had fewer reef passes that were farther apart.

As islands age, they subside, or sink, into the ocean, which reduces the amount of land that funnels rainwater into rivers. Eventually, rivers are too weak to keep the reef passes open, at which point, the ocean likely takes over, and incoming waves could act to close up some passes.

Gillen is exploring ideas for how rivers, or river-like flow, can be engineered to create paths through coral reefs in ways that would promote circulation and benefit reef health.

“Part of me wonders: If you had a more persistent flow, in places where you don’t naturally have rivers interacting with the reef, could that potentially be a way to increase health, by incorporating that river component back into the reef system?” Gillen says. “That’s something we’re thinking about.”

This research was supported, in part, by the WHOI Watson and Von Damm fellowships.

Good article from 404 Media on the cozy surveillance relationship between local Oregon police and ICE:

In the email thread, crime analysts from several local police departments and the FBI introduced themselves to each other and made lists of surveillance tools and tactics they have access to and felt comfortable using, and in some cases offered to perform surveillance for their colleagues in other departments. The thread also includes a member of ICE’s Homeland Security Investigations (HSI) and members of Oregon’s State Police. In the thread, called the “Southern Oregon Analyst Group,” some members talked about making fake social media profiles to surveil people, and others discussed being excited to learn and try new surveillance techniques. The emails show both the wide array of surveillance tools that are available to even small police departments in the United States and also shows informal collaboration between local police departments and federal agencies, when ordinarily agencies like ICE are expected to follow their own legal processes for carrying out the surveillance...

In-house attorneys say it was illegal for Attorney General Rob Bonta (D) to hire an outside firm to oversee the high-profile case against the oil industry.

Analysts say the administration's anti-wind policies could delay or cancel more than $100 billion in offshore investment.

A new analysis shows that almost every nation failed to submit stronger goals for reducing carbon pollution by the Paris Agreement's deadline.

A POLITICO analysis identified 794 planned clean electricity generation facilities — mostly in GOP districts — that could lose subsidies under the House bill. The Senate is debating changes.

The findings come as President Donald Trump’s proposed budget cuts jeopardize the data-gathering missions and other forecasting tools.

The bill, which awaits the governor's signature, aims to lower the carbon intensity of the Oregon Public Employees Retirement Fund.

Republican leaders are racing to pass the legislation before Independence Day.

Galena, a sprawling village of 400 people along the Yukon River, is shifting to clean energy to reduce its reliance on expensive, imported diesel.

New research on six staple crops found that rice alone would have the smallest decline in global yields.

The scorching conditions for a wide swath of the country from Chicago to New York are forecast to last through next week.

Torrential rains over steep coastal mountains and the landslides and flooding they could generate are an ongoing concern for officials.

Water makes up around 60 percent of the human body. More than half of this water sloshes around inside the cells that make up organs and tissues. Much of the remaining water flows in the nooks and crannies between cells, much like seawater between grains of sand.

Now, MIT engineers have found that this “intercellular” fluid plays a major role in how tissues respond when squeezed, pressed, or physically deformed. Their findings could help scientists understand how cells, tissues, and organs physically adapt to conditions such as aging, cancer, diabetes, and certain neuromuscular diseases.

In a paper appearing today in Nature Physics, the researchers show that when a tissue is pressed or squeezed, it is more compliant and relaxes more quickly when the fluid between its cells flows easily. When the cells are packed together and there is less room for intercellular flow, the tissue as a whole is stiffer and resists being pressed or squeezed.

The findings challenge conventional wisdom, which has assumed that a tissue’s compliance depends mainly on what’s inside, rather than around, a cell. Now that the researchers have shown that intercellular flow determines how tissues will adapt to physical forces, the results can be applied to understand a wide range of physiological conditions, including how muscles withstand exercise and recover from injury, and how a tissue’s physical adaptability may affect the progression of aging, cancer, and other medical conditions.

The team envisions the results could also inform the design of artificial tissues and organs. For instance, in engineering artificial tissue, scientists might optimize intercellular flow within the tissue to improve its function or resilience. The researchers suspect that intercellular flow could also be a route for delivering nutrients or therapies, either to heal a tissue or eradicate a tumor.

“People know there is a lot of fluid between cells in tissues, but how important that is, in particular in tissue deformation, is completely ignored,” says Ming Guo, associate professor of mechanical engineering at MIT. “Now we really show we can observe this flow. And as the tissue deforms, flow between cells dominates the behavior. So, let’s pay attention to this when we study diseases and engineer tissues.”

Guo is a co-author of the new study, which includes lead author and MIT postdoc Fan Liu PhD ’24, along with Bo Gao and Hui Li of Beijing Normal University, and Liran Lei and Shuainan Liu of Peking Union Medical College.

Pressed and squeezed

The tissues and organs in our body are constantly undergoing physical deformations, from the large stretch and strain of muscles during motion to the small and steady contractions of the heart. In some cases, how easily tissues adapt to deformation can relate to how quickly a person can recover from, for instance, an allergic reaction, a sports injury, or a brain stroke. However, exactly what sets a tissue’s response to deformation is largely unknown.

Guo and his group at MIT looked into the mechanics of tissue deformation, and the role of intercellular flow in particular, following a study they published in 2020. In that study, they focused on tumors and observed the way in which fluid can flow from the center of a tumor out to its edges, through the cracks and crevices between individual tumor cells. They found that when a tumor was squeezed or pressed, the intercellular flow increased, acting as a conveyor belt to transport fluid from the center to the edges. Intercellular flow, they found, could fuel tumor invasion into surrounding regions.

In their new study, the team looked to see what role this intercellular flow might play in other, noncancerous tissues.

“Whether you allow the fluid to flow between cells or not seems to have a major impact,” Guo says. “So we decided to look beyond tumors to see how this flow influences how other tissues respond to deformation.”

A fluid pancake

Guo, Liu, and their colleagues studied the intercellular flow in a variety of biological tissues, including cells derived from pancreatic tissue. They carried out experiments in which they first cultured small clusters of tissue, each measuring less than a quarter of a millimeter wide and numbering tens of thousands of individual cells. They placed each tissue cluster in a custom-designed testing platform that the team built specifically for the study.

“These microtissue samples are in this sweet zone where they are too large to see with atomic force microscopy techniques and too small for bulkier devices,” Guo says. “So, we decided to build a device.”

The researchers adapted a high-precision microbalance that measures minute changes in weight. They combined this with a step motor that is designed to press down on a sample with nanometer precision. The team placed tissue clusters one at a time on the balance and recorded each cluster’s changing weight as it relaxed from a sphere into the shape of a pancake in response to the compression. The team also took videos of the clusters as they were squeezed.

For each type of tissue, the team made clusters of varying sizes. They reasoned that if the tissue’s response is ruled by the flow between cells, then the bigger a tissue, the longer it should take for water to seep through, and therefore, the longer it should take the tissue to relax. It should take the same amount of time, regardless of size, if a tissue’s response is determined by the structure of the tissue rather than fluid.

Over multiple experiments with a variety of tissue types and sizes, the team observed a similar trend: The bigger the cluster, the longer it took to relax, indicating that intercellular flow dominates a tissue’s response to deformation.

“We show that this intercellular flow is a crucial component to be considered in the fundamental understanding of tissue mechanics and also applications in engineering living systems,” Liu says.

Going forward, the team plans to look into how intercellular flow influences brain function, particularly in disorders such as Alzheimer’s disease.

“Intercellular or interstitial flow can help you remove waste and deliver nutrients to the brain,” Liu adds. “Enhancing this flow in some cases might be a good thing.”

“As this work shows, as we apply pressure to a tissue, fluid will flow,” Guo says. “In the future, we can think of designing ways to massage a tissue to allow fluid to transport nutrients between cells.”

More than half of the nation’s 623,218 bridges are experiencing significant deterioration. Through an in-field case study conducted in western Massachusetts, a team led by the University of Massachusetts at Amherst in collaboration with researchers from the MIT Department of Mechanical Engineering (MechE) has just successfully demonstrated that 3D printing may provide a cost-effective, minimally disruptive solution.

“Anytime you drive, you go under or over a corroded bridge,” says Simos Gerasimidis, associate professor of civil and environmental engineering at UMass Amherst and former visiting professor in the Department of Civil and Environmental Engineering at MIT, in a press release. “They are everywhere. It’s impossible to avoid, and their condition often shows significant deterioration. We know the numbers.”

The numbers, according to the American Society of Civil Engineers’ 2025 Report Card for America’s Infrastructure, are staggering: Across the United States, 49.1 percent of the nation’s 623,218 bridges are in “fair” condition and 6.8 percent are in “poor” condition. The projected cost to restore all of these failing bridges exceeds $191 billion.

A proof-of-concept repair took place last month on a small, corroded section of a bridge in Great Barrington, Massachusetts. The technique, called cold spray, can extend the life of beams, reinforcing them with newly deposited steel. The process accelerates particles of powdered steel in heated, compressed gas, and then a technician uses an applicator to spray the steel onto the beam. Repeated sprays create multiple layers, restoring thickness and other structural properties.

This method has proven to be an effective solution for other large structures like submarines, airplanes, and ships, but bridges present a problem on a greater scale. Unlike movable vessels, stationary bridges cannot be brought to the 3D printer — the printer must be brought on-site — and, to lessen systemic impacts, repairs must also be made with minimal disruptions to traffic, which the new approach allows.

“Now that we’ve completed this proof-of-concept repair, we see a clear path to a solution that is much faster, less costly, easier, and less invasive,” says Gerasimidis. “To our knowledge, this is a first. Of course, there is some R&D that needs to be developed, but this is a huge milestone to that.”

“This is a tremendous collaboration where cutting-edge technology is brought to address a critical need for infrastructure in the commonwealth and across the United States,” says John Hart, Class of 1922 Professor and head of the Department of MechE at MIT. Hart and Haden Quinlan, senior program manager in the Center for Advanced Production Technologies at MIT, are leading MIT’s efforts in in the project. Hart is also faculty co-lead of the recently announced MIT Initiative for New Manufacturing.

“Integrating digital systems with advanced physical processing is the future of infrastructure,” says Quinlan. “We’re excited to have moved this technology beyond the lab and into the field, and grateful to our collaborators in making this work possible.”

UMass says the Massachusetts Department of Transportation (MassDOT) has been a valued research partner, helping to identify the problem and providing essential support for the development and demonstration of the technology. Technical guidance and funding support were provided by the MassDOT Highway Division and the Research and Technology Transfer Program.

Equipment for this project was supported through the Massachusetts Manufacturing Innovation Initiative, a statewide program led by the Massachusetts Technology Collaborative (MassTech)’s Center for Advanced Manufacturing that helps bridge the gap between innovation and commercialization in hard tech manufacturing.

“It’s a very Massachusetts success story,” Gerasimidis says. “It involves MassDOT being open-minded to new ideas. It involves UMass and MIT putting [together] the brains to do it. It involves MassTech to bring manufacturing back to Massachusetts. So, I think it’s a win-win for everyone involved here.”

The bridge in Great Barrington is scheduled for demolition in a few years. After demolition occurs, the recently-sprayed beams will be taken back to UMass for testing and measurement to study how well the deposited steel powder adhered to the structure in the field compared to in a controlled lab setting, if it corroded further after it was sprayed, and determine its mechanical properties.

This demonstration builds on several years of research by the UMass and MIT teams, including development of a “digital thread” approach to scan corroded beam surfaces and determine material deposition profiles, alongside laboratory studies of cold spray and other additive manufacturing approaches that are suited to field deployment.

Altogether, this work is a collaborative effort among UMass Amherst, MIT MechE, MassDOT, the Massachusetts Technology Collaborative (MassTech), the U.S. Department of Transportation, and the Federal Highway Administration. Research reports are available on the MassDOT website.