Introduction: Cylindrical Aeroponics Growth System
For the Grow Beyond Earth contest, I wanted to design a gardening system that had functionality and efficiency at the forefront of it’s features. This system is enclosed by a plexiglass cube but unlike other traditional bottom-up enclosures this has a floating cylinder center serving as the plant bed. The cylindrical design maximizes plantable surface area and free outward growth in two directions. The hallow cylinder's center serves as the housing for the plant's root systems and the hydroponic mist system. The system is completely sealed unless ventilated to recover unused fluids. For use in gravity, a suction device must be placed on the bottom to drain excess fluids. In space however, a suction pump can be placed opposite of the water lines and feed back into the space stations water recovery system. The watering system is Arduino based and completely automatic to ensure plants only receive the water they need to thrive. I opted for the aeroponics system because they have been known to increase growth speed and yields for vegetative and flowering plants while conserving an incredible amount of water in the process. Aeroponics has a wide range of other benefits including improved disease control, nutrient feeding, and overall usability. This Aeroponics system can be used throughout the entire lifecycle of plants from seed to harvest.
This design can be scaled for larger operations with multiple cubes. For example, there can be a cube with multiple cylinders with LEDs in between for germination and early plant life. Then a model like this one can be used up until harvest.
This model does not contain any consumable items like soil and other grow mediums to enhance efficiency and sustainability.
1x 5m LED strip https://amzn.to/2GQ37WZ
1x Arduino Uno R3 https://amzn.to/2GKPuZu
1x Two channel relay https://amzn.to/36KxSat
1x 12VDC Waterpump https://amzn.to/2vHb4M5
5x acrylic plexiglass sheets https://amzn.to/31eZe7D
16x 90 degree brackets https://amzn.to/3b4Q5CT
2x small hinges https://amzn.to/2SdZkIm
1x 100% clear silicon https://amzn.to/2tYVURX
4x mister nozzles https://amzn.to/2RQxkvI
1x roll of 1/4in misting hose https://amzn.to/2RNe9CL (cheaper in store)
1x two port irrigation manifold https://amzn.to/2RRqGoZ (Cheaper in store)
1x roll 3/8" hose https://amzn.to/36K50zj
1x 1/2" female to male hose adapter https://amzn.to/2GOagHi (Much cheaper in store use link as reference)
30x 2" Net pots
30x 2" foam cloning collars
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Step 1: Building the Housing Cube
Adhere to the volumetric constraints (a 50cm cube).
1. Using the plexiglass sheets from the supply list, draw a 50cm by 50cm square. Ensure that all angles are equal otherwise the cube will not fit together.
2. Use a plastic cutting tool like the one listed in tools or a dremel with a cutting bit (Plastic tool works much better) and cut out your first square face. This square will act as a template for the next 5 faces for the cube.
3. Once cut, clean up the edges and use this square as a template and create 5 more faces.
4. To assemble the cube you must do half at a time. Before assembly Two 1/2" holes, one on the top and one on the bottom need to be drilled in the center for the cylinder supports. I laid out 3 squares in an "L" shape and connected the edges temporarily with clear tape. Once the bottoms are secure with tape lift the two sides and secure them with tape as well (shown in the picture).
5. Repeat step 4 for the other half of the square faces then place on half on top of the other and use tape to secure them together.
6. Once secure, start attaching brackets to edges, first drilling, then placing screws. DO NOT bracket every edge! One face should be left completely detachable. This face will become the door.
7.Using hinges of your choice place them on the remaining cube face.
8. I used 100% clear silicon to seal edges, however, this is optional. REMEMBER, DO NOT silicon the door closed.
9. Set aside for later use.
Step 2: Building the Lighting and Waterpump Circuit
This circuit is very simple to minimize overall footprint and decrease potential malfunction. Using an Arduino Uno R3 (or other off brand) microprocessor we will control the LED and waterpump function. They will both be on individual schedules. While in space water must be rationed therefore we need to build a system capable of releasing only the required amount of water for each plant.
Arduino Board ---> Two Channel Relay
5v to VCC
GND to GND
Pin 12 to IN2
Pin 13 to IN1
Since there are so many available pins this project could incorporate more sensors to enhance functionality of the growth system. Some things I may add are temp/humidity sensor and LCD to display remaining run times for lights and water. These features will be useful for ventilation.
Step 3: Code
First, declare all of the pins and constants. This time schedule can be refined to optimize plant growth.
const int LED = 12;
const int WATERPUMP = 13;
const long onDurationLED = 43200000; //On time for LEDs
const long offDurationLED = 28800000; //Off time for LED
const long onDurationWATER = 20000;//On time for waterpump
const long offDurationWATER = 36000000;//Off time for waterpump
int LEDstate =LOW;//initial state for LED is ON
int WATERstate =LOW;//initial state for waterpump is ON
The setup and void sections establishes the rules for the timed events. It doesn't need to be adjusted if you want to change ON/OFF durations, use the constants above. If you hook up the relay in normally open you will need to change the HIGH and LOW values accordingly. Download the code to view it.
Step 4: LED Setup
I cut the LED into strips because it didn't lay flat in a serpentine shape.
1. Cut the strip on the markings at roughly 8-12".
2. Solder the pads and connect each series.
3. I used extra jumper cables I had laying around to save money but any combination of pins and wires will work.
4. Periodically test the strip to ensure each section is connected properly and in series.
5. Evenly space 8 strips on the bottom and top of the cube ensuring the power connector is on the bottom near an edge.
Step 5: Irrigation Setup
1. Connect a single strip of tubing long enough to loop around to the second port. Approx. 15"
2. Using misting nozzles and t-barb splitters, connect 5 misters evenly around the loop I alternated spray direction.
3. Connect male to hose connection to the port manifold and attach 19" of 3/8" tubing to the hose connection.
4. Set aside
Step 6: Building the Cylinder
Be very careful when drilling acrylic it is very fragile and prone to cracking. I used a 2" forster bit to drill holes for the net pots.
1. Using a plastic knife or dremel cut out two circles with a diameter of 16".
2. Start to drill holes for the pots. I drilled as many holes as possible with at least 1 inch spacing. Drill as many as you would like.
3. Drill a 1/2" center hole in each circle.
4. You can start to glue pots in. I use a plastic bonder, super glue didn't work that well.
5. Cut a piece of the landscape edging equal to the circumference for your cylinder. formula is 2*pi*r (or just google it)
6. I did one side at a time using plastic bonder. Applying liberally to the edges of the edges. Once full coated I laid the circular piece on top and weighed it down. (don't use too much weight)
7. After about 15 minutes you should be able to repeat for the otherside. However, REMEMBER to insert the misting nozzle inside with the hose protruding the centered hole.
Step 7: Final Asssembly
1. I used a variety of 1/2" diameter PVC and male to male attachments to support the cylinder. The same effect can be obtained by cutting two lengths of PVC for the top and bottom of the cylinder. Since my cylinder was roughly 5 inches I cut my pvc to about 6.5 inches to compensate for attachments. All of these parts can be found at the local hardware store. The main idea is to have two main support pieces secured to the top of the cube and top of the cylinder then the bottom of the cube and cylinder.
2. The bottom support must be hollow so the tubing from the irrigation can run through the bottom of the cube.
3. The top support I used is also hollow. This is not necessary for earth operations, but provides access for a suction pump in space. This pump can be used to pull out unused moisture and return it to the ships reclamation system.
4.After assembled the cylinder should spin freely. This allows for easy access to tend to or harvest plants.
5. I attached all of the electrical equipment to the outer cube side closest to the LED power connector.
6. The pump on the bottom attached to a water source. Ideally on the space station this could be hooked into the onboard plumbing.
7. I also used some extra net pots as feet to prevent obstruction of the irrigation.
8. To actually grow something you need 2" foam clone collars (found on amazon or other hydroponics stores)
9. Add clone to collar and insert into net pot
10. Seeding is possible with clone collars as well I was able to germinate basil
Step 8: Conclusion
This grow system has really came to life. The aeroponics system has great potentiaI. Using 3-dimensional geometric figures may solve the problem on the space station. This is only one example of over 6 million different geometric shapes. By utilizing geometry we can scale this system to benefit the different stages of plant development from seed to harvest with minimal effort. This cube is also very easy to disassemble and assemble through the use of brackets as opposed to a frame. This can be quickly disassembled and stacked for shipment.
I had an amazing time building this project and learned so much. I have really opened up to indoor growing as a hobby and decor. The combination of nature and technology is amazing and has no limitations.
If you have any questions let me know.
Second Prize in the
Growing Beyond Earth Maker Contest