Rice University Students Create Indoor Farming Device

Rice University Students Create Indoor Farming Device

By Rebecca Hazen, rebecca.hazen@chron.com

Photo: Lettuce Turnip The Beet

Published 4:11 pm, Tuesday, May 23, 2017

A group of mechanical engineering students at Rice University, called the Lettuce Turnip the Beet team, have come up with a way to cultivate vegetables indoors.

A group of mechanical engineering students at Rice University have come up with a way to cultivate vegetables without needing a large plot of land outdoors.

The Senior Capstone Design project, made up of students Jared Broadman, George Dawson, Sanjiv Gopalkrishnan and Dominique Schaefer Pipps, aptly named their group "Lettuce Turnip the Beet." (LTTB)

According to group member Gopalkrishnan, the mechanical engineering department pitched different projects to the senior students, including a vegetable cultivation machine, and the four choose to work on that particular project.

The main goal of team LTTB, through the vegetable cultivation machine, was to produce one salad per week, for a year.

"Other goals were to make the project sustainable, easy to build and operate, and able to be used in an apartment setting. We have achieved all of our goals - our most recent harvest yielded eleven salads after four weeks of growth," Gopalkrishnan said.

The team has been working on the project since August, and created two versions, both with vegetables growing hydroponically - without soil. The first prototype is in an enclosed area outside. It is based on a triangular frame, has three circular grow tubes, and two pumps with inputs into each of the tubes. It is about 6 feet tall. The second prototype is inside. It is eight feet tall, hosts six square grow tubes, and one pump with an input to the top of the tube arrangement.

"The wooden frame of the second prototype is modular, in that it is composed of four two foot tall sections of two-by-fours, held together by dowel rods. The frame was designed this way to facilitate customization and easy transport. The pipes are square because they are easier to fit into the framework, and have a larger bottom area for the roots to lay upon as the nutrient solution flows across them," Golpalkrishnan explained. "The one input was chosen for ease of operation, as the pipes are all connected in a gravity fed cascade. It is vertical for easy user access. The triangular shape of the first prototype made it hard to access plants at the top. We use a Platinum P900 LED to feed plants at the top of the device, with two smaller fluorescent lights to supplement the bottom plants. The entire device draws about the same amount of power as a microwave."

Golpalkrishnan continued, "We learned quite a bit from the first iteration that we implemented into the second, final prototype. We built the first prototype in November 2016 and the second prototype in February 2017."

It may seem complicated, but the reality is that growing plants is straightforward. They just need light, water, nutrients and a place to grow.

"If the system is set up properly (which is easy to do, and takes about an hour per week to maintain), the plants grow on their own. The biggest key to being able to grow indoors is a good grow light. Plants will grow without light, but one cannot harvest a salad per week without a good light. As far as anyone being able to do this - the answer is yes. Three of the four of our team had no gardening experience, and we have learned as we go," Golpalkrishnan said.

Tomatoes are currently being grown in the outdoor prototype, because there is easy access to pollinators. The LTTB team found that it was easy to grow leafy greens indoors because they do not require pollination. The indoor prototype is currently growing lettuce, kale, Swiss chard and spinach. There are also herbs like basil and parsley, and the team even managed to grow a carrot and radish.

"It is amazing to see the whole plant cycle, from seedling, to adolescent plant, to being able to harvest them. The device has made it easy for us to grow our own vegetables, and our hope is that the device can combat the negative practices utilized by industrial agriculture," Golpalkrishnan said.

Recently, the team showed off their work at the Engineering Design Showcase, which is an event for all Rice engineering teams. Lettuce Turnip the Beet won the Best Environment and Sustainability Design Award.

As the last part of the project, the team will travel to Gothenburg, Sweden, at the end of this month. There, the device will be implanted at the HSB Living Lab at Chalmers University.

"That trip will be the culmination of our efforts as a team, as we are going our separate ways after graduation. However, at least two of us will be building our own versions of the device for personal use," Gopalkrishnan said.