Hi YaduSharon, For the parametric file on fusion, I have it linked on my online streaming version. I have not been able to download a desktop version of Fusion to install on my computer, only a stream version which saves my files online. Here is a link you can download the files at: Fab Academy Week 20




Week 20

Final Project




Project

Design and prototype a chamber that can maintain the conditions needed to germinate microsopic seeds and spores in any climate.



Controls
Temperature - increase or decrease from 60-85 degerees
Light - artificial on a timer scheduled to simulate growth cycles
Hermeticity - initially 100% to isolate the fragile seeds, then reduce in increments of 10% to gradually expose the seeds to the outdoors
Puncturable - in case of emergency to drain or add ingredients or water
Humidity monitor - to more precisely test and measure growing environment


Introduction

The conditions required for orchids to grow in the wild exist because of symbiotic relationships with other organisms. In order to reproduce epiphytes in laboratory conditions, equipment such as autoclaves and laminar flow hoods are used to create sterile growing environments.

My mentor suggested that I look into some of the equipment that is built for the Bio Academy to see if there were any relevant examples already in use. I checked out:

Open Culture Technology

I couldn't find a device that would fulfill the function I needed so I continued by searching past student projects. I found one project :
Biosphere - by murasaki at Fab Lab Kitakagaya
A device to keep and log a closed ecosystem



The project is a very good example of a chamber with similar controls. The main difference will be the hermetic control needed for epiphyte type plants to grow.


Initial Design

I began by laying out the process of orchid fertilization in the wild to consider all the factors that needed to be considered for germination to occur.








Background

I first tried growing orchids from seed in 2014. I collected 36 different species of seed pods of varying sizes and species to have a large sample group.


I built some homemade laboratory equipment (like this homemade sterile chamber) to use to transfer the seeds to their pre-prepared growing environment.


I prepared the seeds using sterilized tongs and scalpels. Some of the seeds were not ready even though the seed pod appeared to be ready.




Without any way to check if the seeds were viable, I proceeded to document them.


And many other seed pods, carefully gathering the seeds in coffee filters.










Using syringes and a solution of 0.1% bleach and water, I rinsed the seeds by filtering them through a cotton swab twice and rinsing with distilled water the last time.




Following online tutorials and using local materials, 32 weeks later I was able to successfuly create protocorms, even though I only had a success rate of 1/16.









Failures

- lighting conditions
timer unplugged, bulb went out, uneven distribution of light to different chambers

- inconsistent temperature
Heat accumulation from direct sunlight

- humidity
inconsistent quantities in different samples

- growing medium
agar formula for nutrients was inconsistent

- seed viability
some seed pods had not formed correctly or had been harvested prematurely




Input / Output

1) Temperature
Input: Maintain 85 degrees fahrenheit

Output: Read colder temperature heat copper wires Read warmer temperature turn off copper wires 2) Humidity
Input: 100% humidity no LED
Output: Variance turn on red LED

3) Light (constant timer)
Input: Set schedule for species
Output: Consistent lighting schedule, variance turn on red LED




Case Design Considerations

Drainage
I used Fusion360 to model a platform to be situated inside of an acrylic dome.

The shape of this style agar container doesn't allow water to pool. This is important to prevent seeds and spores from floating off of the surface of the agar medium.



Vessel shape
I chose a bell shaped container for condensation to ciculate without dripping into the agar container.


I was able to source this from a local acrylic provider as they had a mold that could make the dome.

The base will contain all of the components with heating coils located beneath the water collection point. The plan is for this to condense excess water if necessary.




Research

Peltier
http://www.penguinslab.com/peltier.htm
operating temp 6.8degrees celcius
12v DC 150 watts
test switching circuit for pwm control by using 2 stage oscillator to control both loads separately

suitably insulated mounting screws required (stop the heat conducting to the cold side through the screws) and the cold heatsink mounted on the cold plate (unless your cold heatsink has mounting holes outside the tec size that can take a bit of force)

thermal grease is used between hot heatsink and tec, cold plate and tec, cold heatsink and cold plate, the type used for CPU coolers.

if the cold sink is to be colder than ambient condenstation will arise

http://www.instructables.com/topics/Question-on-using-a-PeltierTEC-device-for-air-tem/

'Peltier Junctions' (aka Thermoelectric Modules) are, as you've already figured out, nothing more than solid state heat-pumps.

circuit ocilator 2 stage = 100hz tec 1= hz1, tec2 = hz2, tec 1 = hz3, tec 2 = hz4, this is a way of switching two tesc with 2 stage ocilator using the power fet irfp054. AN SUPER POWERFULL FET.

temp monitor software https://www.meerstetter.ch/products/systems-software-accessories/tec-service-software seebeck generators

Is it possible to use the peltier module to switch between the heating and cooling effect, with the help of some device like a temperature controller? What I mean is, I want to create a box that will keep the ambirnt temperature inside at 65 - 70 degrees constantly. So if the temp. drops below 65, the hot side can kick in to heat it....or if the temp. goes above 70, the cooling side will kick in with the help of a heat sink and fan. ...is this at all possible? I don't fully understand how TEGs work.

you can do this with TEC's (thermal electric cooler) but not with TEG's (thermal electric genorators). the wires on a TEG are soldered to one side that is supposed to be used as the cold side. This is so the wires don't become unsoldered when extreme heat is put on the hot side. TEG's are rated up to 400 Celsius. TEC's will never have this problem because they will never get hot enough to unsolder them selves unless you stack more than a few on top of each other to increase your cooling and heating capacity. you should be able to build your devise easily with no problem.

best example - https://www.youtube.com/watch?v=PUGFwfLHP4M