Yiannis Levendis, a professor of mechanical and industrial engineering at Northeastern University, has developed a prototype firefighting robot that sprays liquid nitrogen onto flames to extinguish them quickly. The project grew from a laboratory experiment in 2008, when Levendis was testing shredded tire rubber as a possible alternative fuel.

“Liquid nitrogen, when thrown on fire, quickly evaporates and expands into gas almost 1,000 percent,” Levendis said. “That suffocates the fire and creates a cooling effect on the fuel.”

He said the flames were extinguished almost immediately, prompting him to explore whether the same approach could be adapted for wildfire response. Northeastern Global News reported that the robot is designed to suppress small fires and hotspots before they grow into major wildfires.

How the robot works

The prototype, built with Northeastern students Hayden Hishmeh and Aobo Liu, resembles a compact all-terrain vehicle with caterpillar tracks, a liquid nitrogen tank and a spray hose. It can be operated remotely or potentially autonomously, allowing it to move into areas that may be too dangerous for firefighters.

Unlike many wildfire retardants, liquid nitrogen does not leave behind chemical residue. As it rapidly turns into gas, it cools burning vegetation while reducing the oxygen available for combustion. The robot is currently being tested on controlled fires using forest fuels common in wildfire-prone areas of the western United States.

Tom Ryden, executive director of MassRobotics, said the approach could appeal to firefighting agencies or industry partners.

“A perfect use for robots is to send them into dangerous spots,” Ryden said, according to Northeastern Global News. “Even if we lose a robot, it’s just the cost of the machine that’s lost, not a person.”

Levendis also believes the cryogenic system could eventually be adapted for much larger firefighting vehicles. “I believe it can be converted to vehicles as large as firetrucks,” he said. “We are fairly close.”

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Field deployment still faces major hurdles

The technology is still in the prototype stage, and significant engineering challenges remain before liquid-nitrogen firefighting robots could be deployed in active wildfire operations. Cryogenic storage, transportation logistics and the amount of nitrogen required for sustained firefighting would all need to be addressed.

Even so, the project points toward a different strategy for wildfire response: using robots to attack small ignition points quickly, especially in terrain that is too risky for human crews. If that approach proves practical, it could become a useful complement to existing wildfire suppression methods rather than a replacement.

Also read: NASA’s robotic rescue mission shows how remotely operated machines can take on high-risk work where direct human access is limited.

This article is brought to you by COMSOL.

In pursuit of improved range, greater reliability, and faster charging, electric vehicles are driving the demand for high-voltage electronics. Other applications driving this demand include wind farms, data centers, and server farms, to name a few. As the interest for high-voltage electronics increases, the risks associated with their sudden failure must be considered.

Much of what causes high-voltage equipment to malfunction can be linked to the conditions of the climate in which it operates. Specifically, condensation on electronic surfaces caused by humidity can lead to corrosion, which can result in stray leak current and dendrite shorting during Electrochemical Migration (ECM).

Predicting, mitigating, and helping proactively design to account for corrosion is the focus of the Centre for Electronic Corrosion (CELCORR) research group at the Technical University of Denmark (DTU). The group’s researchers are working with industry partners to develop models and simulation apps that will help in building robust electronics designs. Their goal is to develop knowledge that can be used for manufacturing electronics to withstand humid operating conditions.

Electronic Failure: “It’s Not the Heat; It is the Humidity”

Automotive electrification and renewable energy systems rely on electronics at all stages of the energy chain. When these electronics, such as the example PCB in Figure 1, are exposed to the effects of moisture, they can become potential failure points.

“Anywhere you are producing, converting, transporting, and using energy, you need these high-power electronic systems that get affected by the humidity,” explained Dr. Rajan Ambat, DTU professor and manager of CELCORR. Ambient moisture can seep into the devices and machines that require these electronics and cause unexpected functional issues through corrosion. When these electronics are involved in particularly high-voltage applications (such as wind farms, data centers, electric vehicles, and server farms), failure due to humidity exposure can even lead to fire.

“There might be a situation where somebody installs a solar panel near the seashore or in an area with high humidity, and within a short period of time, a conducive condition forms inside the electronics that results in a failure,” Ambat said. “This is why we need to understand exactly how the conducive condition of condensation is created, when the condition is created, and how the system is failing.”

Figure 1. The electrolyte potential and current density distributions on a PCB surface (with pinholes).CELCORR/DTU

Identifying corrosion as the underlying cause of some electronic failures is still a challenge. “Fifty percent of failures in electronics are currently branded with an unidentified root cause,” Ambat explained. “When engineers open up the system, they do not realize that the failure was due to corrosion, because moisture disappears without leaving any sign of corrosion unless there is ECM dendrite formation.”

This lack of awareness was a strong motivator for CELCORR, which turned to multiphysics simulation as a supplementary tool to help its partner organizations to better predict humidity-related issues at the design stage.

Modeling Moisture and Measuring Parameter Changes in PCBs

CELCORR believes the best way to identify and avoid electronic failures is to build more effective designs that better prevent corrosion from developing or can withstand a higher humidity load. Its research team applies its expertise in modeling to generate simulation apps that will help partner industries to evaluate safe designs for humidity robustness.

“We are at the intersection of materials science and the electronics industry. We work as a bridge between materials and electronics disciplines, using both kinds of language,” Dr. Anish Rao Lakkaraju, a postdoctoral researcher at CELCORR, explained.

To understand potential design issues, Ambat emphasized the importance of virtually breaking down systems to identify where problems may arise. “We need simulation software to analyze potential uses of designs and whether new designs are good or bad,” Ambat said.

Researchers at the Technical University of Denmark (DTU) are using simulation apps to predict corrosion and design electronics proactively to mitigate or withstand its effects.

Using the COMSOL Multiphysics software for investigation, the CELCORR research team together with other research partners (Aalborg University) built an example model with a simple PCB geometry that matched both its test circuit boards as well as the design of a device used by one of its partner companies. The team then added a water film layer on top to act as the relative humidity. From there, the team could introduce variation. “We change the layout, geometry, distance between electrodes, thickness of the water film, and conductivity of the water film depending on the conditions,” Ambat said.

Ambat and his team generate data on the effect of these variations and can identify which has the greatest impact on the device’s performance and whether any alterations can improve the device’s anticorrosion robustness. “We assume there is condensation forming on the electronic surfaces (Figure 2) and compute the electrochemical leak current for different design elements,” Ambat said. “The value of the computed electrochemical current between the parts will give us an indication of whether the PCB will be affected or not.”

Figure 2. A 10-µm water film condensation effect on an example PCB.CELCORR/DTU

Altering the design elements and solving the model equations again and again allows the team to better understand what makes a design effective. “Now, we are at the current form of the model, and we are quite happy with where the physics are at this point,” Lakkaraju said. This modeling, however, was just the first part of CELCORR’s overarching goal of illuminating the destructive potential of corrosion in electronics and the best ways to avoid it.

Using Simulation Apps to Test Real-World Designs

To open up and ease access to these models, CELCORR used the Application Builder in COMSOL Multiphysics to create simulation applications for the members of the industrial consortium. Built with a simple 3D circuit board geometry with two oppositely biased electrodes and a water layer to replicate corrosion-causing moisture, the apps provide a pared-back, straightforward interface where users can vary model inputs. “We focused on fundamental aspects,” Lakkaraju said. “We boiled down our partners’ overarching concerns to create two apps with very simple geometries and the simplistic stuff that can be varied over multiple parameters.”

The simple simulation apps shown in Figures 3 and 4 are designed to show companies how the distance between the electrodes and the thickness of the moisture layer affect the leak current through the water film depending on different parameters. By analyzing multiple design elements and parameters, users can determine the relative benefits of certain design elements on the humidity robustness. “The apps we have built have really helped because they give the electronics engineers a plug-and-play sort of approach,” Lakkaraju explained.

Figure 3. The UI of CELCORR’s standalone app showing the inputs that users can alter.CELCORR/DTU

“By using this app [Figure 3], companies have unlimited freedom to work with these sorts of variables,” Lakkaraju added. “This would be quite difficult to recreate in real life with physical design and testing, and the companies we work with are quite happy with the level of accuracy the app can provide.”

Figure 4. The UI of one of the simulation apps showing a streamline plot with inputs such as the cathode voltage and blockage length.CELCORR/DTU

Looking Forward: Complex, High-Voltage Modeling

Alongside its collaboration with the industry consortium, CELCORR is also working toward improving the world’s general understanding of corrosion’s impact on electronics. To do this, Ambat and his team are undertaking multiple projects, including actively adding greater complexity to their models. In a tertiary current distribution model they are building, the team is drilling down into each of the basic inputs used in a secondary current distribution model, zooming in to examine the effects of the set of even more detailed inputs each basic input comprises.

“The next point is to study what each of these detailed inputs does,” Lakkaraju said. In particular, the team is examining mass transport properties and the chemical reactions’ rate constants.

In addition to these ongoing studies, CELCORR is expanding the scope of its research to investigate corrosion in high-power, high-voltage systems. Thanks to a 2024 grant from the Grundfos Foundation, CELCORR was able to establish the Centre for Climate Robust Electronics Design (CRED). The center’s lab facilities and expertise are being developed to address the humidity-robustness requirements of today’s high-voltage and high-power electronic equipment. “Using CELCORR’s uniquely deep understanding of materials and corrosion, we are equipped to find the root cause and provide knowledge for environmentally robust designs,” said Ambat.

For all of its investigation, CELCORR continues to rely on the agility of the COMSOL Multiphysics software. As Lakkaraju explained, “It is really quite nice how a model can be adapted to a variety of combinations of materials, geometries, and parameters and how the software allows you to keep building on from there.”

Cybersecurity startup Horizon3 has raised a $250 million Series E at a $2 billion valuation, more than tripling its valuation in 14 months. The San Francisco-based firm drew backing from returning investors NightDragon and NEA.

The funding arrives as two major AI research labs disclosed last week that their models had breached systems outside their intended scope. Horizon3, which has spent six years building AI specifically designed to probe networks for vulnerabilities in a controlled, authorized manner, is riding growing enterprise demand. With AI-driven attacks accelerating, enterprises are rushing to stress-test their defenses at scale, a gap that traditional security vendors have largely left unfilled.

Matt Hartley, the company’s chief revenue officer, said that its NodeZero platform has two core strengths: It can test live systems without shutting down operations, a capability other AI-powered tools have struggled to deliver reliably, and it scans an entire infrastructure continuously rather than once a year, examining the full network rather than just 2-3%.

The company approached $100 million in annual recurring revenue last year with 120% year-over-year growth,and expects to accelerate growth this year, Hartley said.

AI tools have made it easier for attackers to develop new exploits quickly, forcing security teams to handle threats faster than they can fix them. Horizon3 spent roughly $100 million in R&D building automated systems designed to stay predictable and controllable, Hartley said. That’s significant given recent breaches at AI labs, which raised questions about whether any AI system can truly remain contained.

“It’s also making people a lot more careful about how they deploy AI,” Hartley said. “We’re getting a lot of questions today around: can you detect AI? Of course we can. But I think a lot of organizations that rushed to deploy AI across the enterprise are now thinking twice about the ramifications of those deployments; what if my own security team gets too aggressive, could there be unintended consequences? So a lot of organizations are moving into what I’d call a bold new world, which is exactly why you need consistent, predictable testing from a company like Horizon3, to know how to strengthen your own defenses against real-world exploits.”

In a statement, Horizon3 has run 310,000 production security tests with zero disruptions, establishing what it calls ‘AI Hackers’, fully autonomous penetration testing.

The real competition isn’t other software vendors; it’s the existing model, according to Hartley. Most companies hire human security firms to run annual tests and those won’t disappear, he continued. What’s shifting is what clients demand after signing up: Instead of sampling 5% of infrastructure once yearly, they now want to scan everything monthly or weekly, tracking whether they’re actually getting safer.

Horizon3’s founders, Snehal Antani and Anthony Pelletier, met while serving at Joint Special Operations Command, where they saw firsthand how resource constraints made continuous security testing difficult. They founded Horizon3 to automate those repetitive assessments.

With the funding, Horizon3 is expanding internationally,including new offices in Amsterdam (in June 2026), Australia, and Singapore, while building a partner network and maintaining substantial R&D spending.  

Strategic investors now include Singapore’s EDBI, defense contractor SAIC, and Qualcomm, signaling that the vulnerability they’re addressing extends well beyond any single sector.

Horizon3 has roughly 7,200 to 7,300 customers, ranging from managed service providers serving small businesses to Fortune 10 enterprises. The company claims an addressable market of tens of billions of dollars, a figure that aligns with industry estimates of the broader cybersecurity market, valued at $271.9 billion in 2025 and projected to reach $663.2 billion by 2033, according to Grand View Research.