tim savas

OpenAg Personal Food Computer™ v3.0

The Personal Food Computer v3.0 is the MIT Media Lab Open Agriculture Initiative’s latest desktop controlled environment growth chamber. We made the Personal Food Computer simpler and smarter than it's ever been. The unit doesn’t require tools for assembly, can be flat packed for easy transport, and sends data to a cloud database. Other new features are abound. I led chassis prototyping and manufacturing for our release in 2018. Described here are my contributions. Check out my team's Wiki and Github pages for a fuller picture.

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Iteration

In 2016 I helped develop the OpenAg Personal Food Computer™ v2.0. We love this tool, as do the hundreds of members in our community who have built it around the world. But we learned a lot from this initial deployment. Specifically, it has a long and somewhat expensive bill of materials, particularly for our younger community members. We redesigned its electronics system into a 12”x12” custom PCB, which both added more control and intelligence while removing complexity.

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Meanwhile the form factor was compacted down from a 6 cu-ft to an even easier to carry and handle 1 cu-ft volume. All told, we reduced the PFC’s assembly time from a full day and high level of difficulty to an easy 15 minutes. V3.0 also has our new, open-source intelligent LED system at its center, that can control six channels of color and more precisely mimic environments in doing so. PFC v3.0 has been quite the evolution for the team and the project.

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Chassis Design

The OpenAg team designed the PFC v3.0 chassis based on a series of initial constraints:

The resulting chassis has press-to-fit jointery, ports for all sensors, and is made of a waterproof, food-safe plastic for ideal hydroponic production. The design was a full team effort, with contributions from our super group of plant scientists, architects, educators, mechatronics engineers, and machine learning experts.

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Design for Manufacturing

I added a set of features to the PFC v3.0 CAD model in order to create design and manufacturing efficiencies during the bot’s development, and ultimately to help our downstream users build their own:

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Chassis Production

I led OpenAg’s in-house manfuacturing of the PFC v3.0 during prototype and production phases, using the MIT Media Lab tooling to produce 60 assembled units. Locking step with OpenAg’s electromechanical team, I ensured proper PCB fit, sensor fit, and ease of assembly throughout my iterations. I ended the production run before our deadline, with extra units to spare.

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The Media Lab's Shopbot is an old horse, so I came up with efficiencies to speed up production. My pace went from an initial single unit in two days, to manufacturing 15 units per week. Here are some tricks and techniques I learned along the way.

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Deployment

"Deploy or die," as we say at Media Lab. My manufactured units weren't just for demo. They were to be delivered to K-12 classrooms in and around Boston for OpenAg's user pilot study, led by the human behavior and health specialist side of our team. Meanwhile my mechanical files were shared on our Github and Wiki to our thousands-strong community.

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To me, the user study embodies the Media Lab's and my own devleoping approach to tool building and research. In building a hardware tool, the PFC, to forward knowledge in plant science, we have, in turn, made a tool to advance human expression and interaction. The PFC v3.0 is not only a controlled environment growth chamber for advancing plant science, but also a platform through which its users can learn, interact, and express.

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I'm looking forward to seeing how our open-source community will deploy their own PFC v3.0's. Perhaps they'll design the "sweetest" tomato, and share it on our forum for others to grow and taste. Or they might explore climate change science, like the kind I worked on in my previous lab, incubating their own local woody plant species to see how they'll respond to future a warming climate. Better yet, they'll build and hack their own PFC 3.0 mod, for new uses our team has yet to think up.

775 670 3447 / tsavas[@]media.mit.edu