Sustainable garden planters

This sustainable garden planter was a capstone project during my senior year of high school, for the Project Lead the Way “engineering design and development” course. In this class, students worked in small groups on a year-long project of their choice. The projects were taken from the problem statement, through the entire design process all the way to a functioning prototype and presentation

I joined a group of two other students, Claire, and Leah, and we began by brainstorming the type of product we would like to develop. We eventually settled on a project that we thought would benefit the environment, as well as be feasible as our first major engineering project. the problem we were attempting to solve was that in especially cold regions, the growing season is greatly reduced for plants, which often don’t have the time they need to grow fully. In addition to this, growing large plants can be difficult inside, but if they are grown outside many are destroyed or eaten while still in infancy stages. Our solution was designing and building a new type of environmentally friendly garden pot that can be grown inside for a limited period of time, then transferred outside into a garden allowing it to be grown in a controlled environment during its infancy stages and transferred outside when the weather permits or when the planet becomes too large to continue to grow indoors.

The project began with concept generation and idea sketching. We narrowed our options to three promising designs which we then evaluated using a decision matrix. From this decision matrix, we determined that concept 3 would be the most feasible and effective design to solve our problem.

Our final design consisted of three-part product: A water collection tray made of PLA plastic, with channels for water drainage and flow, an outer protective PLA shell which would be the main part of the pot on display and would also serve to protect the inner lining. This would also be equipped with holes on the bottom for water to drain through. The last part was an inner lining made out of biodegradable mycelium, a type of pliable fungus that can be molded into virtually any shape. This would house the soil and the plant itself. This would be designed so it could be easily removed from the outer shell and would also be equipped with holes for the water to drain through

The user would keep the pot and infant plant indoors, growing it like a regular indoor plant for about a month and a half. This allows the user to begin growing their plan in winter or early spring without having to worry about the weather being too cold. it also allows plants to grow in a safe environment while they are small so they are not attacked by pests or small animals. When the plant starts getting larger and the weather gets warmer. The mycelium lining can be removed from the protective shell and placed in a garden outside where the mycelium will decompose and the plant can continue to grow as if it never left the pot. This design eliminates root shock that usually occurs when a plant is transferred from a pot to a garden and does so in a completely environmentally friendly way. This stage of the design project also involved patent research and from this research, we were able to conclude that no existing solution like the one we proposed existed.

We created our first prototype in Autodesk inventor 2018 and 3d printed both the mold that would be used to create the mycelium lining, as well and the PLA shell and water collection tray. We used the mold to cast the mycelium lining, which fit flush with the outer shell

To evaluate our prototype we created a series of tests and test-pass criteria:
The temperature range for the mycelium part of the pot- A test will be run to measure how the pot fares in different temperatures from -50°C in the freezer to 100°C in the oven.
Drop test/material strength test- To test the pot’s durability different recipe samples will be taken off the plastic and drop them from a height of 6′ and measure how many dents, cracks, etc. it suffers. This is to mimic the damage the pot would incur if it was to fall from a shelf in someone’s house The test will be successful if there are less than or equal to 3 dents and 0 cracks.
Its resistance to water – The mycelium will be soaked in water for 30 minutes and observe the water’s effect on the mycelium.
A decomposition test-The mycelium decay will be observed for up to one month, and the decay will be modeled to determine when the mycelium will completely decompose. This method must be employed, rather than waiting for full decomposition because there is not enough time to wait for full decomposition and obtain accurate results.
Two decomposition tests will be conducted. One will be inside a house, with normal temperature and humidity, the other will be in a garden (in the dirt). This will most likely be conducted inside using an artificial garden and a grow light, due to the fact that the weather prevents us from conducting tests outside. These two decomposition tests are based on the two environments that the mycelium will be in. A house for the first part of its life, and the ground for the second part of its life. To do this, the volume of the mycelium will be recorded every day for a month. It will then be put in a graph and modeled as a curve.

We took the data from our tests and used it to improve our design. Most notable, we changed the angle of the side of the pot and increased the base width which ensured that the mycelium didn’t get saturated with too much water, which would cause the bottom of the lining to deteriorate over time. We also changed the thickness of the mycelium lining to ensure the decomposition would take two months rather than three. This involved making changes to our mold and shell in Autodesk. 

Our final prototype met all of the specifications outlined in our initial design. It could effectively grow small plants indoors, and easily transfer them into gardens without making a mess or harming the environment. This pot can be used alternative to peat pots, traditional plastic pots, or corn starch linings. in addition to the prototype, we also ran a cost analysis on our prototype, as well as identified manufacturers that could produce each part.