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Let Them Wear Dirt: Penmai Chongtoua Turns Soil Into Textiles

fabric scraps and penmai chongtoua
Scraps of BioEarth fabric, which is comprised of over 60% soil. The novel fabric was made by Penmai Chongtoua (right) and Professor Lola Ben-Alon of the Natural Materials Lab at Columbia’s Graduate School of Architecture, Preservation, and Planning. Photos courtesy of Natural Materials Lab

Penmai Chongtoua pulls out fabric scraps from a jar and lays them on a table. The strips have a leathery feel and a slight sandiness. They are astoundingly thin and strong, considering they’re composed of over 60% soil. These are samples made of the novel “BioEarth fabric,” which she co-designed — through a painstaking process — to be worn as clothing.

“It’s so interesting the way this material behaves over time,” says Chongtoua as she examines the cracked edges of the scraps, which are slowly drying and becoming less flexible over time. “It evolves and has its own life cycle.”

After graduating from the MA in Climate and Society program at the Columbia Climate School in 2022, Chongtoua came to work as an associate researcher in the Natural Materials Lab at Columbia’s Graduate School of Architecture, Preservation, and Planning. Directed by Professor Lola Ben-Alon, the lab explores the use of low-carbon, non-toxic building materials. The space is filled with buckets of earth and clay, chunks of granite, and fibers such as hay, hemp, and hair-like flax. Bricks, curtains, pottery, furniture, and other intriguing products created from these materials decorate the lab.

Unique among her labmates, Chongtoua is trying to turn those earthen materials into wearable products. Her hope is that by bringing us intimately close to an element that most of us rarely consider in our day-to-day lives, her textiles will encourage people to examine their relationship with Earth, and perhaps re-imagine more symbiotic ways to coexist with it.

Social fabrics

Chongtoua wasn’t the sort of child who played in the mud. She grew up in Colorado, surrounded by natural beauty that she felt disconnected from. As the daughter of first-generation immigrants transplanted to a majority white community, interacting with green spaces seemed to be tied to a culture she wasn’t necessarily a member of.

Although she knew she loved the environment, she felt that something was missing: the human element. Chongtoua believes that human beings should not be considered as separate from “pure” nature. So, as an undergraduate at Brown University, she studied environmental politics in order to explore the relationships between people, communities, and our natural, built, and social environments.

To take it a step further and try to understand how to deepen the symbiotic relationships between people and their environments, she enrolled in the MA in Climate and Society program at the Columbia Climate School.

It was during the Climate and Society program that she found out about the Natural Materials Lab. Ben-Alon, the lab’s director, was looking for a graduate research assistant to conduct life cycle analysis for a project. Chongtoua was captivated, and although it turned out she didn’t have the software expertise for that particular role, Ben-Alon was impressed by her passion and desire to work in the lab, so they brainstormed other ways they might collaborate.

During their conversation, Chongtoua brought up her design background in textiles and fashion, cultivated during her undergraduate studies. Fabric and clothing had always appealed to her not only because of their function as a basic human necessity, but also because fabric and clothing communicate culture, technology, politics, and social information.

“I’d always been drawn to the relationship between textiles and the body, and then also how that relationship impacts our relationship to the social world and to the natural world and to the built world,” she says. “It’s all interconnected for me.”

Brainstorming with Ben-Alon, the two of them began to wonder how those relationships would be different if the textiles were made of earthen materials. Thus, their collaboration was born.

“I had no idea I would soon turn into a material scientist,” says Chongtoua. “I had no idea I was going to be conducting in-depth microscopic studies of the material and cross-pollinating with research hubs like the Liang Tong Lab and the Climate Imaginations Network, and just connecting with so many interesting humans who are asking the same philosophical questions as I am.”

Material evolution

Chongtoua’s first goal was to explore what it would mean to wear earth.

Her first earthen garment was molded to a model’s body like a cast — heavy, solid, and inflexible. The model could wear it only while sitting or lying still. As a result, she felt very meditative while wearing it. It enabled her to slow down and reflect.

One of the main conclusions from this first phase of research, explains Chongtoua, is that when wearing earth, “you’re able to think more critically, more intentionally, and more mindfully about the interactions you have with the environment.”

woman lying on the ground wearing an earthen top
The lab’s first generation of earth-based clothing was sculptural and static, encouraging stillness and meditation. Photo courtesy of Natural Materials Lab

The next step was to make the material more dynamic, just like the human beings wearing them. Chongtoua and Ben-Alon considered a variety of ways to increase its flexibility. Should they change the process in which it’s constructed? Should they interweave the soil with natural fibers?

In the end, they decided to test out bioplastics — plastics derived from natural materials such as corn starch, cellulose, or alginate found in brown algae.

With chemistry flasks, a hot plate, and a cooking pot, Chongtoua carried out a rigorous series of experiments trying out dozens of “recipes” combining soil, fibers and various bioplastics in different quantities.

“Finally, we found a recipe composition that has over 60% of soil — so the majority of the material is still soil-based,” says Chongtoua, “but it is a flexible, wearable, movable piece of fabric.”

This new “BioEarth fabric” was strong enough that it could be laser-cut, embroidered, and machine-sewed. Chongtoua incorporated pieces of it into a kimono that is vastly lighter and more flexible than her first-generation garments.

kimono made with bioearth fabric, seen from multiple angles and in motion
Lighter, stronger, and more flexible, the second generation of earth-based clothing — like the pieces on the kimono here — has more dynamic applications. Photos courtesy of Natural Materials Lab

Next, she hopes to continue improving upon the fabric until it matches the strength and flexibility of mainstream textiles like cotton. Toward that end, she recently started working with a bioplastics expert on campus to try out new iterations and recipes.

She and Ben-Alon are currently developing a course that would teach future designers and architects the art and chemistry of bioplastics and earth-based materials. Additionally, they are working with Columbia Ventures to register a patent on the fabric invention. They also aim to expand public engagement around the new fabric, to envision other applications for it.

Slow fashion

Will the sustainable, biodegradable fashion of the future be made of BioEarth textiles?

Not so fast, says Chongtoua. She and Ben-Alon are proceeding cautiously when it comes to envisioning their textile on the mass market.

Currently, the Natural Materials Lab uses waste soil from construction sites. But if BioEarth fabric were produced on a large scale, it’s difficult to imagine that process similarly relying on waste soil.

The BioEarth fabric is strong enough to be laser-cut (left), machine-sewn (middle), and embroidered (right). Photo courtesy of the Natural Materials Lab

Over a century ago, petrochemical plastic was introduced as a sustainable alternative to chopping down forests for commercial production of natural gums and resins. Today it has grown into its own environmental crisis. Humanity has seen many times that mass production can lead to massive environmental impacts.

“When we’re thinking about the scalability of BioEarth fabric, will scaling its production processes also produce environmental catastrophe in the future?” asks Chongtoua. The starches and vinegar she uses to make the bioplastics also have to be produced somewhere, she notes, and those processes have an impact as well.

The solution may lie in a decentralized approach of sharing the research with other groups who can apply it locally in their own supply chain and extraction contexts, she says.


One of the things that made this work possible, says Chongtoua, are the interconnections she formed at the Columbia Climate School.

People, culture, clothing, and the environment — these are all interwoven for Chongtoua, and not just figuratively. She says that being a part of the Climate and Society program was a turning point for her career, because it connected her with a community of world-leading professors and peers with radical perspectives.

“Columbia really gave me the opportunity to build meaningful relationships with like-minded people who had the same kind of philosophical goals for their vision of what a sustainable world is.”

Columbia campus skyline with text Columbia Climate School Class Day 2024 - Congratulations Graduates

Congratulations to our Columbia Climate School MA in Climate & Society Class of 2024! Learn about our May 10 Class Day celebration. #ColumbiaClimate2024

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