The Rhizosheath Project
Overview
The Rhizosheath Project is the result of an independent study under Professor Mathew Schwartz at the New Jersey Institute of Technology. My role in the project was to take the research done by former biology student, Monica Torralba, and create an automated plant growth and documentation system to assist biologists study the growth of plant roots in different aggregates.
Skills
Python, Sketching, 3D Modeling, 3D Printing (SLA and FDM), Laser Cutting, Woodshop Tools
Team
Mathew Schwartz (faculty advisor) and Monica Torralba (biology researcher)
The Requirements
Create an automated plant growth system with the following features:
- UV day/night lighting cycle
- Nutrient cycle
- Photo documentation cycle
Initial Ideation Sketching
First of Many Problems to Solve
Failed efforts in filling the growth volumes or “sheaths” from the top down with one pump led to the idea of chaining the sheaths together and filling them from the bottom up.
Quick Model
Model made with lab trash to show off the new “Daisy Chain” bottom up method.
Concept Diagram
Visual diagram detailing the updated filling and draining system.
Proof of Concept
Manual demonstration of the automated task of filling the sheaths with one water pump.
And after much iteration...
The final version of the nutrient distribution system.
Automated Task Demonstration
Lighting Cycle
LED grow lights are coded to cycle through “day/night cycles” of 16 hours on 8 hours off
Camera Documentation
Twice a day, a camera module is pulled along a track with a belt and pulley system. As the roots are contained separately from the top half of the plant to keep them from prolonged light exposure, a brief flash of white led light is used to capture the root photo before the module is moved along to the next sheath.
Nutrient Dosing
As the plant nutrient begins to degrade after approximately 48 hours after being mixed into water, it was important to develop the dosing chamber. When it is time to distribute the nutrient, water is pumped into an acrylic chamber until a float sensor is triggered. The time it takes from the instant the pump is turned on to the instant the float sensor is triggered is used in a formula to calculate the volume of water in the chamber. From this calculation, the correct dosage of nutrient is pumped through an automated syringe into the tank, and mixed by a submergible liquid agitator.
Nutrient Distribution
After being mixed, the nutrient is fed into the interconnected sheaths, resulting in the water level to rise simultaneously. The first sheath always first to be filled, resulting in a slightly higher water level than the rest while being filled. For this reason, an initial “dummy sheath” was placed before the sheaths. This “dummy sheath” houses a float sensor at the correct top fill height of the sheaths. When triggered, the sensor temporarily pauses the pumping of the nutrient water, allowing the water level to even out. After a few seconds, the pumping continues, and this process is repeated until the time between the sensor triggers are negligible.
