What Is a Personal Food Computer?

A farm the size of a desktop could change the way we grow food in cities

Caleb Harper

The personal food computer looks like a fish tank. It’s the right shape and size, but there’s no water. Inside the two-foot-long box, under glowing purple LED lights, lettuces and legumes sprout up, their roots, free of dirt, misted by digitally-controlled sprayers. It’s a tiny, low-water, climate-controlled agriculture system, designed for growing food in cramped city quarters. The machine is plugged into a network, so all the environmental information runs into a database, where other farmers can see how much water and light the plants are getting, and use that data to tweak the way they grow their own crops.

Call it open-source farming or data-driven agriculture. Either way, it’s a way to program how we grow what we eat. Caleb Harper, an engineer with a background in architecture and design, developed the personal food computer. He also runs the City Farm group, which looks at innovative ways to grow food in urban areas, at MIT’s Media Lab. He thinks his contraption is the future of food.

“It’s a digital interface that controls physical object,” Harper says. “What’s cool is that at the end of your grow cycle you get a digital recipe. If you were to grow basil again, you would get the same thing every time. You can email the basil recipe to your friends, and they can run the program again and get the same thing, or they can start messing with it.”

That "recipe" would include all the variables the farm would need to adjust to re-grow the basil the same way, like the amount of light and water, or the carbon dioxide levels inside. It's essentially the climate for the box. Those environmental factors are what make food taste and grow a certain way, and Harper is most excited about having the ability to control the system for other outside factors, to make food as good as humanly possible. "People talk about the phenome and the genome," he says. "We're not doing anything in the genome, we're just messing with the phenome."

The food computer plugs into the water and electricty in any building, and doesn't need any other resources, which is why it makes sense in a house or a classsroom. It uses shallow water culture and raft hydroponics to spray the plants' airborne roots instead of saturating soil. Farmers can grow just about anything that they could in the ground, as long as it doesn't get taller than four feet. Harper says his team has had good luck with greens and berries. He's trying to get the cost of the system down to around $300, so it would make sense for a classroom to buy one.

Harper comes from a family of famers, so he understands scale and what it takes to grow crops commercially. But he’s not just trying to farm more efficiently. He thinks the biggest gap in the food system is in the way we communicate about growing, and he’s building tools to fix that. By building small, connected farms, and creating a network and a database, he wants to change the way farmers share information and grow their food.

What Is a Personal Food Computer?
Harper has had good luck growing greens. Caleb Harper

Harper doesn’t actually believe that everyone can feed themselves out of a fish-tank-sized farm. Because it's four feet square, it can grow something like four heads of lettuce in four weeks. In September, he’s going to set them up in five schools in Cambridge, near MIT, as tools to teach kids the biology, engineering and creativity associated with farming. These student testers, in turn, will expose what works and what doesn't. This initial step will also be a way to get the database in place.

There’s a dearth of young farmers in the U.S. The average age of farmers in this country is 58, according to the most recent census, and, especially as we move more toward urban agriculture to provide local food for people in cities, there’s going to be a need for farmers who are both digitally savvy and aware of what it takes to bring a crop to fruition.

“There’s a lack of people and lack of modern tools in this world,” Harper says. “My goal is to create more farmers through the box.”

Despite the lack of skilled farmers, urban agriculture, as a concept, is growing. Cities, such as Boston, have changed their zoning laws to allow for farming within their limits. Harper says there are a lot of people designing and building small-scale, digitally-managed farms, like Freight Farms, out of Boston, with its Leafy Green Machine, a hydroponic shipping container farm. But they’re operating in silos, and not talking to one another. “To me that’s kind of boring,” he says. “I want to be building the network. People care right now, more than they did 20 years ago, but they want solutions, so now is the time for actually building platforms.”

Harper is working on two other models of urban farms that use the same principles and networked controls as the personal food computer. One is the size of a shipping container and could be used by a restaurant or an apartment building. The other, at 500 square feet, is industrial-sized, and could be used for commercial production.

“The thing that unites everything is that it’s all open source, the hardware, software and data,” he says. “I want to give everybody a place to go to share knowledge on a structured platform.”

Harper is launching the Open Ag Initiative, a new lab within the Media Lab, in September. The lab will pull in students, researchers and other faculty, as well as people from the tech and the agriculture industry, to work on the food computer and the network. Once he feels like he has the design for the food computer dialed in, he’s going to make it available to anyone who wants to grow veggies aeroponically in their living room. Users will be able to download the specs, or order a kit, and tinker.

“I’m kind of agnostic of what they get used for,” Harper says. “All I want to do is be a toolmaker, put them out there and see what happens. I don’t want to be telling people what they should do. I just want to democratize the growing of food.”

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