Alum Asks: Can We Grow Buildings?

Laura Maria Gonzalez SM ’22 came to the Department of Architecture at MIT with a big question about tiny organisms. She began the SMArchS master's program in 2020 with a background in design and digital fabrication. But her diagnosis with an autoimmune disease that impacts the microbiome, or bacteria in the gut, had turned her attention to the powerful role that microbes play, not just in bodily health, but in shaping the natural world.

“Bacteria have this incredible ability to break down minerals or to change the chemistry of an area to promote mineral formations,” Gonzalez says. “As an architect, I found that incredibly exciting.”

Once she recognized that microbes are responsible for mineral formations like stalactites, icicle-shaped deposits often found inside caves, Gonzalez saw the potential for leveraging the dynamic relationship between bacteria and minerals to create organic building material: “The big question I brought to MIT was, can we grow buildings?”

The culmination of Gonzalez’s three-year exploration was on vivid display last summer in “Microbes Make Mountains,” an exhibit of her thesis project at MIT’s Keller Gallery. Funded in part through a grant from the Council for the Arts at MIT (CAMIT) and the MIT Department of Architecture, the exhibit included insights into Gonzalez’s laboratory process and the ultimate outcome of her intensive experimentation and design: otherworldly sculptures cast from biocement, a material created through the synergy of microbes and minerals.

“I’ve learned that in the sciences, it’s really easy to find a rabbit hole and just continue going down,” Gonzalez says. “My hope with the exhibit was to bring people into this magical, invisible world that I’ve been inhabiting for the past three years.”

Micro Scale, Macro Impact

Gonzalez drew inspiration for “Microbes Make Mountains” from natural wonders characterized by reactions between microbes and minerals, including the Rio Tinto in Spain, a river with crimson water and copper-colored banks, and Ethiopia’s Danakil Depression, a triple junction of tectonic plates suffused with brilliant shades of green and turquoise. “We often look at sites like these and just see chemistry and geology at play,” Gonzalez says. But videos in the exhibit helped visitors understand the significant role that microbes play in the physical formation and bold hues of these sites.

Gonzalez also worked with the Department of Material Science and Engineering to take scanning electron microscopy (SEM) images of the reaction process, allowing visitors a close-up look at how she facilitated the growth of biocement. “I discovered that if you add a particular bacteria to soil or sand and feed it a specific formula, it creates crystals by gluing the particles together,” Gonzalez says. “Over the course of about a week, you go from having a soft pile of sand or soil to a hard object.”

To create the bone-like sculptures on display in “Microbes Make Mountains,” Gonzalez made casts of smaller, interlocking pieces, and combined various minerals and microbes inside each one to facilitate the growth of biocement. The sculptures’ design and shape reflect both fabrication needs, like stability, and the needs of their living microbes, including plenty of surface area to allow them oxygen. “You’re trying to strike a balance between what the microbes need and what you want them to do,” Gonzalez says, a delicate process that MIT allowed her the resources to figure out.

Curiosity That Drives Solutions

Tending to living organisms in a lab was new territory for Gonzalez when she arrived at MIT. Originally from Havana, Cuba, Gonzalez earned a bachelor's in architecture from Carnegie Mellon and spent four years working on the construction of a Manhattan office tower. The experience had shown her how carbon-intensive concrete is to produce, and stoked her interest in biocement.

The idea to grow buildings required interdisciplinary synergy, and Gonzalez credits her adviser, Skylar Tibbits, associate professor of design research in the Department of Architecture, for encouraging her to take classes across different areas of study. A course called How to Grow (Almost) Anything, offered through the MIT Media Lab, became both a jumping off point for her own project and inspiration for courses that Gonzalez later taught through Independent Activities Period (IAP) and as a teaching fellow in her third year.

Gonzalez developed her process for creating biocement in the MIT BioMakers space, where she first learned how to work in a wet lab, with guidance from the director, Justin Buck, and later became a lab supervisor. “It was a dream to have this community of experts to consult about how to make this project a reality,” Gonzalez says. “I was able to look at these questions and ideas from so many different perspectives, which is so unique to MIT.”

That spirit of discovery, combined with access to leading scholars and scientific tools, encouraged Gonzalez not to give up—even when she couldn’t get her microbes to behave the way she wanted them to until two months before her thesis deadline. Another institution might have urged her to present renderings instead, Gonzalez said, but Tibbits and other mentors pushed her to keep going.

“MIT fosters this sense of relentless curiosity that keeps you questioning and continuing to explore, not knowing what you’re going to find,” Gonzalez says. “There’s a sort of magic here that really pushes ideas beyond what we’re doing in the lab to ask how we can impact our world.”

For Gonzalez, that means continuing to refine her development of biocement as a potential building material at Genspace, a community biology lab in New York City. “I want to see how far we can take it as a sustainable alternative,” Gonzalez says. The fact that biocement is alive, and requires a measure of human care, could also shape how people think about their relationship to the world they inhabit, Gonzalez says: “How could this process help us see ourselves as stewards of our environment who understand the flows of nature?”

This story was originally published by Arts at MIT.

Photos courtesy of Laura Maria Gonzalez