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tennessee technological university

TTU News

Published: Tue Oct 18, 2011

thumb Trey_Brooks_10TTU chemical engineering senior designs way to optimize plant growth

Research summary:

Trey Brooks, of Gallatin, Tenn., has been designing circuit boards and computer codes to control light wavelengths to optimize plant growth. Since plants absorb red and blue light, he has devised a way to control LED lights to give plants only what they need. The process, when combined with sustainable aeroponics horticulture techniques, conserves energy and allows plants to grow faster.


Holly Stretz, TTU professor of chemical engineering

Research procedure, findings:

“The experiment will start with lettuce because it grows quickly. With an aeroponic system, your plants are more consistent with each other, which is good because you can really tell what’s going on with them.”

“The LEDs allow us to optimize the light levels we’re giving the plants. The different amounts of red or different amounts of blue can affect leaf-gas exchange with the atmosphere and stem elongation and the actual biomass of the thing.”

Research application:

“All visible light can be expressed as combinations of red, green and blue frequencies. The reason plants are green is because they reflect all that green light; they only really need red and blue.”

“Current agricultural methods use more water, energy and light than necessary. LEDs are more efficient than traditional fluorescent bulbs. This lessens the draw on resources for indoor horticulture. Now, we can make LEDs so they are wavelength efficient.”

“Eventually we’ll be using an aeroponic root system, which cuts down on about 99 percent of the water usage. That is pretty significant because 70 percent of the fresh water on earth is used for agriculture.”


The chemical engineering major received some limited funds from the Governor’s School for Emerging Technologies and the department of chemical engineering for allowing a high school student to help him with writing computer codes. He has not received any external research grants, but the TTU Electrical and Computer Engineering students have also helped him with startup resources.


What motivates you to do this research?

“Indoor growth is really cool because you can have skyscrapers of gardens. You can grow, in a perfectly controlled environment, plants from all over the world.”

“Eventually, I’d like to make it cheap enough that I can feed the world. If I can put a jab into world hunger, that would be great. If you could put a storage container with this stuff in it in Africa, you could sustain a small to moderate sized community.”

What are your future plans?

“Research is a tool to my goal and my goal is to help feed the world.”

Is this research integrated into classroom instruction?

He collaborated with a high student with experience writing computer codes who participated in the Governor’s School for Emerging Technologies. Together, the pair wrote the code that controls the intensity cycle of light emitted by the LED bulbs.

Describe the undergraduate research component.

He hopes to be able to incorporate the project into his senior design course.

What have been the biggest challenges you’ve faced in this area?

Funding and space; Brooks says he is hopeful that some lab space will open up so he can start growing lettuce and see how the system works in reality.

What would your dream job be, using this research?

“Eventually, I’d really like to make this into an agriculture business, providing consultation to pharmaceutical companies as they’re always looking for cheaper components for their products. With that revenue, I can reinvest in produce to help provide food to the hungry.”