Meet this year’s MathWorks Fellows: A three-part series, III

The 2020-21 School of Engineering MathWorks Fellows use MathWorks software to design space habitats, improve irrigation systems, create faster, light-driven computer technologies, and optimize subterranean carbon storage

When the Perseverance Rover landed on Mars last February, it carried with it an oxygen generation experiment called MOXIE. The instrument uses electrolysis to split oxygen out of a Martian atmosphere predominantly composed of carbon dioxide. When the system is initiated, it can produce enough oxygen for one human to breathe for a little more than ten minutes.

But as part of her master’s degree research, recent Department of Aeronautical and Astronautical Engineering graduate and current SpaceX mission integration engineer, Katherine (Katie) Carroll, worked on a hypothetical MOXIE scale-up. Basically, she wanted to determine “the specifications that a system would need to use this oxygen production system to support a future human mission to Mars,” she says. Oxygen generated by a scaled-up MOXIE could also potentially be utilized to produce propellant for the vehicle that would return humans to Earth.

Carroll’s Martian habitat research was supported by a MathWorks fellowship. MathWorks is a software company that was founded in 1984 with the goal of providing researchers with new and more powerful computational tools. In 1985, the company sold ten copies of its first product, MATLAB, to MIT. MATLAB is a programming language that can be used to develop algorithms, analyze data, and build mathematical models. Almost forty years later, MIT students and faculty continue to wield MATLAB, and another MathWorks product called Simulink, to advance research across disciplines.

In 2019, in celebration of the decades-long partnership with MIT, MathWorks began awarding fellowships to graduate students in the School of Engineering who utilize MATLAB and Simulink in their research.

For her work on the MOXIE scale-up, Carroll built a system optimization algorithm in MATLAB and used Simulink to run simulations. During her master’s research, Carroll also used MATLAB to model hypothetical human movement patterns in a future Martian habitat called Star City. Such modeling is necessary to determine the best transportation options and layout for future stations.

“In reflection, [MATLAB] is truly the software that I believe gave me the confidence to say ‘Yes, Katie, you can be an engineer…and solve really complex, amazing problems,’” says Carroll.

Presently residing on Earth, Carroll likes to get outdoors to go hiking, backpacking, and rock climbing, or to play tennis.

Rather than designing systems for other planets, Lluís Saló-Salgado, a MathWorks fellow and PhD student in the Department of Civil and Environmental Engineering, focuses his research deep within our own.

He’s digging into some important details related to carbon capture and storage, a proposed climate change mitigation strategy in which carbon emissions would be captured from point sources such as coal plants, steel mills, or chemical facilities and then injected into geological formations underground. However, there is a concern that once the gas is injected, it could just escape out of geological faults which are, essentially, everywhere.

“Right now, we are at a stage with…CO₂ storage, that in order for this to make a significant impact when it comes to reducing the worldwide CO₂ emissions, we need to be doing it at scale,” says Saló-Salgado. “Every country should have some projects…so it’s impossible, basically, to ignore [geological faults]. We need to live with them.”

To determine the best places to potentially inject CO₂, Saló-Salgado uses MATLAB to simulate CO₂ storage and develop high-resolution models of fault zones. These models help him investigate how geological material distribution in the area affects fault permeability at large scales.

When he’s not in the lab, Saló-Salgado enjoys rock climbing and reading. He was previously a representative of the Department of Civil and Environmental Engineering for the MIT Graduate Student Council and is currently the treasurer for Spain@MIT.

Operating on a much smaller scale than that of planets and geological formations, Haowei Xu, a MathWorks fellow and PhD student in the Department of Nuclear Science and Engineering, is seeking new, more efficient materials to be utilized for the construction of computer components. Familiar technologies, such as computer processors or USB drives, function by using thermal energy to initiate the material phase changes necessary to relay information. However, if the components were constructed of different materials, light could hypothetically be used to initiate phase changes.

“If you can trigger phase transitions with light, then the phase transitions can be very fast and very efficient. Energy efficiency can be very high,” says Xu. “We are proposing mechanisms and new materials for these kinds of applications.” He is also investigating new materials that could be utilized for efficient light detection, and to generate lasers.

Xu uses MATLAB to process data, write code, and run simulated light interactions with different experimental materials.

“I use MATLAB almost every day,” he says.

Xu is a sports fan, making time to watch basketball, football, and table tennis games in spite of his busy lab schedule. Trying to find more ways to entertain himself while social distancing during the pandemic, he’s also taken up a cooking hobby.

Fiona Grant, a MathWorks fellow and PhD student in the Department of Mechanical Engineering, enjoys hiking, running, and baking for friends. She also counts herself lucky that her research—which involves optimizing drip irrigation systems—requires travel to field sites.

“Agriculture accounts for a significant portion of freshwater usage globally, and reports indicate that to sustainably feed a growing population, farmers will need to both reduce the amount of water that is consumed and intensify production on farmland that already exists,” she says.

For a few reasons, Grant’s research focuses specifically on systems meant to benefit small farms in arid regions of the world. While smallholder farmers and indigenous people are often excluded from participating in policy decisions, these groups tend to have essential knowledge about sustainable farming techniques and crop types for their region, she says. Further, some studies suggest that intensification may be more successful per unit area on smaller plots of land.

Grant, along with her colleagues, built an optimization tool in MATLAB that can help design low-cost, solar-powered drip irrigation systems based on local weather, crop, and field layout inputs. She is now using the software to create an energy management controller that leverages the intrinsic variation in the system’s power flow to reduce operational costs and ensure reliability.

“The goal of our work is to design a high-performance product…that is economically and technologically accessible to smallholders while taking into account local conditions and available materials,” says Grant.