Welcome to the biological city of the future. As we move deeper into an age of biotechnology, and contend with the burden of the climate crisis, we face dueling challenges: How do we leverage nature to engineer a better future, and how do we do so sustainably?
This project features the perspectives of people working on inventive answers to this question. The landscape is enormous, so this project does not attempt to capture all the technology that will get us where we want to be. But we hope it serves as one small picture of where we could one day arrive, propelled by the power of synthetic biology. Bon voyage.
TABLE OF CONTENTS
1. Living Utilities
2. A New Home
3. Resilient Infrastructure
4. Life in the Biotechnological City of the Future
“Net zero is not enough. A building itself has to have a positive impact on the environment. So it could be carbon negative buildings, or it could be promoting life and biodiversity, it could be about social cohesion, or ecosystem restoration.”
—Rachel Armstrong, Professor of Regenerative Architecture at KU Leuven in Belgium and Senior TED Fellow
Section 1
Living Utilities
Wastewater treatment that can survey disease like a “prosthetic immune system”
“That was quite a powerful vision during the pandemic. You had places like Princeton testing the sewage in order to say whether or not we still had a pandemic. And the question was, could we actually have this kind of local designed surveillance microbiome that was looking out for our health?”
–Rachel Armstrong
Thinking of urban earth as fractionated soils
“Just as how the different fractions in crude oil perform different functions from wax to diesel—each different fractions can perform a different function within a modern life. Soil is a complex material that is spatially organized. The organisms at the top of the soil like light and oxygen, whereas maybe two or three centimeters down, they start to become more anaerobic, their metabolisms change there. If you do this at the level of the community, your compost performs aerobic work at the top, anaerobic work at the bottom—you’re getting hydrogens and methanes and maybe building blocks for some bioplastics or other materials.”
–Rachel Armstrong
Disease surveillance
Sampling sewage for circulating pathogens has been estimated to be 60 times less expensive than clinical diagnostics.
“COVID brought wastewater surveillance to the attention of policymakers. Scientists pioneered this method many years ago, but it’s never drawn as much attention as it has during the pandemic. The system is sensitive and detects when the virus is present, not just when people get tested.”
–GROW, Go Big or Stay Home
“Think of it like a watchtower on a hilltop, overlooking the forest. If there is a wildfire, if there’s a danger, you can spot it from a distance, inexpensively. And you can look all day long. All things that clinical testing cannot do.”
–Rolf Halden, director of the Biodesign Center for Environmental Health Engineering at Arizona State University in GROW
Comingling waste and electricity
“We could now think of microbial biofilms as a kind of environmental immunology that could operate through your living space. To actually have a home-based environment where every citizen has an ability to clean up microplastics, viruses, and toxins that are just the byproducts from their everyday existence is very appealing.”
–Rachel Armstrong
Rethinking where we get our energy, and how we use it
Engineers can recycle carbon at industrial scales. LanzaTech describes their microbes as “architects of sustainable progress” to address global challenges of excess carbon. Today, they produce ethanol at commercial scale. The future can bring various other commodities currently being tested at lab and pilot scale.
“By using a technological process we call biorecycling, LanzaTech captures and processes multiple forms of waste carbon, such as emissions before they can enter the atmosphere or garbage otherwise destined for landfill. Energy-intensive industries today are equipped with LanzaTech’s bioreactors that are not only able to curtail their emissions but also convert carbon-rich gases into valuable raw materials, like ethanol. At the core of this technology is the use of gas fermentation from a bacterium called Clostridium autoethanogenum. As we continue engineering its genome, we envision a future where strains of this bacteria effortlessly transform various forms of carbon into a multitude of essential chemicals. With this already in practice across various industries such as clothing, car tires, cleaning surfactants, and sustainable aviation fuel, we envision a cityscape with buildings constructed from materials made of recycled carbon emissions and planes flying overhead with a drastically lower carbon footprint—all of which promote a commitment to circular urban ecosystems.”
–LanzaTech
Employing microbial industries
A pioneering example of living architecture is Ioannis Ieropoulos’ “pee power” to generate energy from urine. Experts envision harnessing this stream of energy in public spaces or emergencies.
“If we think of the pee power, as a basic unit, we can think about biotechnology that could lay different levels of engagement with the microbiome, within our bodies, buildings, and the local environment, and the biosynthesis that occurs in those microbial communities. ”
–Rachel Armstrong
Genetically modified carbon-suckers
Last year, the biotechnology company Living Carbon, became the first group to plant genetically modified trees in US forests. Cofounder Maddie Hall argued the case that her team’s engineered poplar trees can scale faster than other carbon removal technology. Where the other more mechanical approaches require new infrastructure, skills, and (consequently) emissions, we already have systems for planting billions of trees annually.
“Our long-term goal is to create some sort of organism that uses energy from the sun to durably sequester carbon for at least 1,000 years, and to really prevent the decomposition of biomass. From a gigaton-scale perspective, by preventing the decomposition of biomass you get an additional 10 gigatons of CO2 per year. Sporopollenin is a highly durable biopolymer that is as close to biologically inert as you can get. So, it’s a really high impact area to work on. We don’t know whether the ideal method of carbon capture is trees or algae — I think it’s both. There’s not going to be a silver bullet. It really depends on the type of land that you’re working on. Think about deserts. Think about the Salton Sea. There’s a lot of areas where it actually wouldn’t make sense to plant trees, but it does make sense to have a cheap bioreactor, because there’s a lot of sun.”
–Maddie Hall, co-founder of Living Carbon, in Grow
Section 2
A New Home
“Homes, whether for a single family or those that include many units, are the building blocks of any community, the foundation upon which everything else is built. Therefore, it is crucial that any sustainable future city is deliberate in creating smart and healthy homes that adapt with us over time.”
– Amit Haller, CEO and Co-Founder of Veev
Living efficiently underground
Civilizations around the world have imagined living stably underground. Residents of the south Australian Outback town, Cooper Pedy, protect themselves from 120 degree summer heat with homes carved into underground sandstone
“I think we’ll see our cities nested in the ground. I’m struck by the image of Cappadocia, the ancient underground city in Turkey. It’s partly carved out of the earth, and partly built above ground. Imagine rammed earth materials, domes that are earth based with simple clays as paints. Our cities could look much more like the ground that we inhabit, rather than gray and alien, as they do today. We will be using things like fiber optics of glass or bioplastics to transmit light down into the ground. The buildings will be warm without needing fossil fuels to heat them. Our biggest challenge will be ventilation and how we filter out dirty air. It’ll feel a little bit like living in a spaceship, but also like being nested within the earth that nourishes us.”
–Rachel Armstrong
Our residential “extended microbiomes” could bring wastewater treatment and disease surveillance into our homes
“We could now think of microbial biofilms as a kind of environmental immunology that could operate through your living space. To actually have a home-based environment where every citizen has an ability to clean up microplastics, viruses, and toxins that are just the byproducts from their everyday existence is very appealing.”
–Rachel Armstrong
Scaling down power requirements with microbial fuel cells
“To be able to design a house, or a lifestyle within an apartment, that could live entirely off a 12 volt supply is one way to greatly reduce the environmental footprint of our living spaces. That would be at the pinnacle of my dreams: to have our own energy that was powered by our own waste and the waste from our kitchens, and that we could still live a decent lifestyle. I think this is going to be possible as we get more types of low power electronics.We’d make a huge dent in our carbon footprint, if we could go from 230 volts, which is about average for a Western apartment, to 12 volts. It’s always important to try to figure out how, by recycling and rethinking the tasks of everyday life, that we can really be smarter about the use of energy.”
–Rachel Armstrong
Our homes should be “digitally alive”
“All future homes must be equipped with clean energy reception capabilities, whether that be solar panels or geothermal heating. Buildings must also be “digitally alive” in the sense that they need to operate in harmony with the homeowner’s unique needs — seamlessly cooling, heating or lighting rooms with ease, flexibility and efficiency. Future or present, homes are the ultimate consumer product and should be built under that pretense.”
–Amit Haller
Use biosensing for responsive buildings
Organisms can be programmed to photoluminesce in response to mechanical stress, resulting in a straightforward visual indicator for a mechanical sensor.
“The most simple bioluminescence we’ve shown is with a very common marine bacteria called Photobacterium kishitanii, but there is also work with bioluminescent dinoflagellates, where physical agitation causes them to give off light.”
–Andrea Ling, biodesigner at ETH Zurich’s Institute of Technology and Architecture, Digital Building
Section 3
Resilient Infrastructure
The climate crisis is here. Old cities must adapt, and new cities need to scale up differently than their predecessors. The construction industry is responsible for 40% of carbon dioxide emissions. Living materials have emerged as a powerful answer.
“We know what we need to do. We have, right now, quite a few interesting solutions, so what is the resistance to implementing these? Is it economic inertia? Is it a fear of changing certain industries, forcing people to learn different skills? The resistance to implementation is not from the researchers—my colleagues can make floor slabs that are 60% lighter than what is out there, with less material but equivalent strength as conventional slabs, but with methods that require more effort and planning beforehand. it’s not a trivial task to implement, but we’re running out of time.”
–Andrea Ling
Solarpunk community bioreactors can change how we grow
“The post-scarcity of Solarpunk is rooted in the community ownership of what sustains its people. While its ethos is radical, the majority of technologies it proposes to get there, like vertical farming, are not. Solarpunk should also have the freedom to reimagine what biology could look like. The emerging synthetic biology toolbox adds resurrecting extinct species and designing new ecologies to the arsenal of ideas. Artists can use them to explore the path between where we are now and the kind of world we want to achieve. What beautiful and strange things would you dare to grow in a guerilla garden?”
–Davian Ho, for GROW
Embracing core principles of biomimicry
“If you look at the spectrum of plastics, they have incredible performance characteristics, but they have horrible characteristics across the rest of their life cycle. Consider the feedstock for making them, the energy requirements, the toxic additives that go into their use. I mean, microplastics alone—we develop these great materials but once they get out of the city environment they’re different from any of nature’s materials. They’re being found everywhere from the bottom of the ocean to all organisms including us. But nature has been using and making polymers since day 1. Proteins and DNA and cellulose—they’re all polymers. I look at nature as a library of materials.”
“Just think of all the different structures made by nature. Hard structures like seashells or exoskeletons, you have flexible structures and appendages like floppy ears or cartilage. They protect from environmental factors—too much water, not enough water—it’s never ending. I would like to see all of that researched and cataloged. What are the principles that underlie nature’s ability to make materials that are extremely high performing, but with life cycles that are in sync with nature?”
–Mark Dorfman
Let microbes make things harder
“A lot of bacteria produce inorganic minerals as a byproduct of their metabolism and enzyme function that can help consolidate structures—or reinforce them. They remain weak, for now; they’re little organisms, but we’re getting increased compressive strength. The most common ones are biocementing bacteria [such as Sporosarcina pasteurii]. They naturally consolidate and make things harder.”
–Andrea Ling
Keep building
“We’re at a point in Europe and North America where a lot of academics think it’s kind of unethical to build, because of the footprint we have on the planet. Except, this is very unfair. You can’t just stop building in the rest of the world — it’s really unfair to countries that are still developing, that they haven’t had the chance to house all of their people or provide infrastructure. So we still need to continue building. We just have to do it in a way that we can incorporate natural systems into these buildings.”
–Andrea Ling
Cover the city’s surface area in carbon sequestering materials
“These materials could be integrated on every facade in a way that’s self-maintaining. They can go through cycles of death and regrowth and maintain some sort of carbon sequestering capacity.”
–Andrea Ling
More mushrooms
“Mycelium biocomposites tend to be attenuated right now, which means that you bake them so that the protein becomes very hard. You kill the spores in them, but you can make quite nice tiles with them.”
–Rachel Armstrong
“In 10 years, I want to see some of the pragmatic stuff that’s in the wings actually get implemented. It’s things like fermented products, like mycelium — it’s probably in food, it’s probably in materials. It’s mostly substitution. If those things make up like 10% of global raw material flows in 10 years, that would be awesome. In 20 years, I could see them becoming a dominant part of the industrial economy, where it’s half of what’s in our homes, our clothing, our vehicles. That’s when we can start to mainline synthetic biology into the environment, like when you start making living things do weird new things. Trees grow medicine and walls that sense if your air quality is poor and release compounds into the air to balance it out. I think that’s more of a 30 to 50 year timeframe. I think that’s pragmatic.”
–Eben Bayer, founder Ecovative, in conversation with Grow
A diverse boom in natural materials
Robots can process bioplastics and knit structures like “tensegrity” style fiber-like pavilions as lattice scaffoldings that can scaffold mycelium biocomposites, biocellulose or bioplastics. The designer and biofabrication pioneer Suzanne Lee introduced us to growing our own clothes with kombucha, in a 2011 TED talk. The microbial tea secretes a rigid skin that can be processed.
“There’s also technology like BioMason’s, where you can create bricks not by kilning but by microbial precipitation. There’s Wil Srubar who has been using more mixed organic materials, including algae. You’re getting the microbes to do the work of the binder, whether those are fungi or bacteria.”
–Rachel Armstrong
Living with sediment
“There’s a lot of research bringing together Earth based materials like clays, sands, silts, to be bound together to form a tile or a soft brick. These are all possible now within a living city environment. Natural clays can be used as paints, as well.”
–Rachel Armstrong
Use Earth as foundation
“We can actually use the excavated sites around us. When we make the foundations for a building, we’re obviously removing living earths. We can use some of that material again, as part of the ingredients for reshaping the fabrics of our houses.”
–Rachel Armstrong
Build decay into our materials
“I am really interested in regenerative cycles and being able to use decay as input for future construction.”
–Andrea Ling
“When nature’s materials break down, you know, they’re breaking down into something that’s not causing pollution, it’s putting nutrients back into the soil or water. That is really what I would like to see: a concerted effort among scientists to understand what is behind that. How do they, at the end of their life, create conditions conducive to life? What do they degrade into and what allows them to degrade and get taken up by other organisms? After collecting all that information, we can start applying that information to how we make industrial things.”
–Mark Dorfman
Recycled steel can lower our footprint
“The construction process must move away from methods and materials that create excessive emissions and waste. For example, every pound of concrete releases 0.93 pounds of CO2. Future cities should use recycled steel instead; it is a cradle-to-cradle material which means it can be reused endlessly without losing structural integrity. That’s just a sliver of what needs to be done to course correct the home-building industry. If we take inspiration from seemingly non-comparable industries, like aerospace or chip manufacturing, there are ample opportunities to build faster, safer and smarter moving forward.”
–Amit Haller
Section 4
Life in the Biotechnological City of the Future
“Art that envisions skyscrapers intertwined with trees and gardens seems to imply that the only thing standing between us and an ecological life is better landscaping.”
–Davian Ho, for GROW
Getting there won’t be easy
As we imagine harnessing the knowledge we gain about nature’s materials, we could choose whether to manufacture them with transgenic organisms or to synthesize artificial analogs.
“I don’t know that it’s an either, or. The microbiome has been getting so much attention these days—the microbiome all over our bodies and all over plants. We’re beginning to understand these microbiomes, like who are the members and what are their roles, and such. And there are people who are working on not necessarily changing organisms, but to actually recreate biomes or selecting for biomes that can generate some material. The processes can be biomimetic as well, where we recreate some biochemical processes. The mimicry does not necessarily use an organism to do that.”
–Mark Dorfman, biomimicry chemist and senior principal with Biomimicry 3.8
Universal healthcare to save money, lives, and reduce the burden of disease
“We are unique in the ways that our health system has just completely sabotaged our own outbreak response.”
–Colin Carlson, a global change biologist speaking with GROW in 2022
Microbial intelligence for transit
“The classical example is a slime mold transport system. The researchers in Japan looked at the optimization of the Japanese underground system by creating a model, and they put the stations as little, little oat flakes as food, and then a slime mold to solve the shortest path. The traveling salesman challenge: slime molds, being an embodied computer.”
–Rachel Armstrong
Designing bioreactors based on the principles of microbial life
Commercial scale equipment is currently biased toward the most docile microbial organisms. But most microbes are capricious, diverse, and form frustrating structures like biofilms. Once we can biomanufacture symbiotically with these microbes, myriad new doors will open.
“What if rather than expecting microbes to perform at their best in tanks borrowed from the chemical industry we built bioreactors with biology in mind? What if we worked with biology, rather than against it?”
–Katia Tarasava, for GROW
Have our food and eat it too
“The hopeful pioneers of cell-cultured seafood promise a simulacrum of this important staple of the world diet, without all the contamination: a bounty of fish, shellfish, and crustaceans, fresher than we’ve ever experienced and entirely traceable. In short: we can eat our fill of fish and still have fish left in the ocean, too.”
–Nadia Berenstein, for GROW
The goal is not just to feed people a singular cell-cultured meat, it is “to give people what they’re getting today, so we don’t feel like we’re losing a major part of culture.”
–Mihir Pershad, cofounder and CEO of Umami Meats in Singapore, in GROW’s Fish Out of Water
Synthetic biology moves forward
“The very knowledge that we swim through microbial worlds should make looking at a steel tank of bacteria a great comfort. A big part of the discussion about GMOs is about how to contain them: minimizing, not maximizing, their impact on the environment. But, compared to thirty years ago, scientists now have far better tools to design GMOs. Unfortunately, the controversies that surrounded them are still intact. For synthetic biology to do better, it must first reckon with its track record.”
–Davian Ho, for GROW
Genetic attribution will bolster biosafety
Genetic engineering’s scale will only grow more unwieldy as the technology becomes more widespread and accessible. But if synbio democratizes to the point where anyone can design a sequence, could the field benefit from anyone being able to trace the origin of a sequence?”
–Claire Hendershot, for GROW
“All technologies concentrate power in the hands of those who have them. So, you want to develop technologies to monitor how people are using genetic engineering. That means attribution.”
– Josh Dunn, Head of Design at Ginkgo Bioworks
An inevitable merger of AI and healthcare challenges how we handle our data
“Think about if every program had machine-readable data that’s open access where appropriate. That doesn’t really exist at scale, and we can build it in from the beginning. But it’s important to mention that if the AI data sets are not diverse, and they’re only representing white urban populations, then we might be optimizing for those populations. So how do we get the other data and reach everyone else? That’s the challenge of working with AI, but I’m excited to see what applications come out of it.”
-Renee Wegrzyn, ARPA-H Director for GROW
