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Presentation Video
Sea Turtle Incubator
A cooling device that can be inserted around sea turtle nests to rectify the sex ratio imbalance caused by rising global temperatures.
Product Contract
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Storyboard
CAD Images
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Additional Links
Contributors
Kaili: (insulation subteam) Insulation material research, CAD, presentation
Kenan: (insulation subteam) Insulation material research, CAD, Collected images
Katana: (insulation subteam) Insulation material research, CAD
Natalie: (insulation subteam) Insulation material research, product contract, storyboard
Bryan: (cooling subteam) Active and passive cooling research, product sourcing, CAD
Viviana: (cooling subteam) Passive cooling and material research, storyboard
Sophia: (cooling subteam) Active and passive cooling research, material research
Emma: (cooling subteam) Passive cooling, material research, CAD, rendering
Rafa: (cooling subteam) CAD, active cooling research
Hanqi: (cooling subteam) Active and passive cooling research, battery research
Kevin: (cooling subteam) Vapor compression and active cooling research, Peltier CAD
Victor: (power analysis subteam) Analytical Calcs and materials research, initial thermal model brainstorming
Laura: (power analysis subteam) Matlab modeling,initial thermal model brainstorming
Oliver: (power analysis subteam) User Storyboard , materials research, initial thermal model brainstorming
Andrew: (power analysis subteam) Matlab Modeling, initial thermal model brainstorming
Nine: (power analysis subteam) Presentation planning, initial thermal model brainstorming
Reviewer Feedback
Georgia Van de Zande
Feedback
- Do the eggs need to have sand, or breathability? Is it dangerous for humans to move the eggs this much? - Do you need a backup? What are the chances your passive cooling won’t function as predicted? The electromechanical backup might have more reliability issues than passive (battery issues, corrosion, etc.) - What material are you using for the pouch part of the product? What are the insulating and breathability specs of it? - After a question from John, you mentioned that you were planning to raise the eggs up closer to the surface. But you had also said that the eggs were deep enough to not experience day/night temperature fluctuations. If you raise them up, is this still a concern?
April Anlage
Feedback
Is there any danger in handling the eggs (multiple times)? I know you mentioned the conservationists monitor the nests, wasn't clear on if handling the eggs is considered normal and safe. The passive cooling seems promising and if it's as reliable and powerful as you say, it would be wise to consider if you truly need the active cooling. Additionally, if the passive cooling is able to cool more than 3 times as much as you need, is there such a thing as too cold? Will the eggs fail to thrive at too low a temperature? I was unclear on how the temperature inside the device is being measured or if it is being monitored in any way. Is there sand within the device or just the eggs? This may affect insulation, etc. You mentioned the lid being level - why does it need to be level? How critical is this? Have you given any thought to cost? A quick google shows a huge range of prices for hydrogel and aerogel, although I'm familiar with both of those materials in more of a research setting. It's also good to start thinking about making the various components sand and water proof. Finally, on your product contract, you have a user need that is "easy to deploy" but the spec is about foam insulation - this seems unrelated. A better metric for deployment might be time to set up or level of complexity.
Tom Dillon
Feedback
Sounds like the team has done great user research and thought a lot about modeling the system - everything was backed up well in the Q&A. I think its great the team is looking into simulation, though sometimes it can be difficult to model all forms of heat transfer using this approach and its pretty time consuming. It sounds like you need to be pretty precise in capturing the various forms that might be at play (conduction in the incubator, sand, convection from the cooling source etc) and keeping the temperature at exactly 27C. Thermal resistance networks might be a quick way of estimating temperature at each point in your system (inside the incubator, in the sand, within the cooling system). This approach would allow you to spec your design and give you a sense of what thickness insulation / amount of active cooling you need before you start prototyping (google "thermal resistance network"/ "conduction in spherical coordinates" as a start, or feel free to reach out!)
James Penn
Feedback
Good progress so far. I agree with you that it would be great to eliminate 1) the need to remove the eggs from the device prior to hatching and 2) the need for an external power source for cooling. For 1), would it be possible, instead of having your cooling lid directly in contact with the sand, to have an air gap between the lid and the sand large enough to accommodate the hatched baby turtles? If the sides and bottom of the device are made of a thermally conductive material, it seems that the cooling lid could still effectively cool the eggs even without being in contact with the sand itself. To allow escape of the turtles from the device and to protect the eggs from predators, perhaps the device could have one-way doors/flaps built into the portion of its sides that is aboveground? For 2), the hydrogel/aerogel approach seems promising, but in case it proves infeasible, could you incorporate a thermally insulated cold chamber into your device (for example, a compartment filled with ice) that is normally separated from the eggs compartment, and could you use temperature sensors and a microcontroller to connect the cold and eggs compartments when the temperature of the eggs compartment rises above a given threshold? Also, in case you haven't seen the study referenced in this article (https://www.wwf.org.au/news/news/2021/new-research-shows-seawater-irrigation-could-help-reverse-male-sea-turtle-drought), it might provide some additional inspiration.
Kamala Grasso
Feedback
I think this is a very cool concept. But it is one where the adage "first do no harm" could come into play. Have you talked to any turtle experts about your approach? Your original design was something went around the nest. But the new design seems to be a container in which the eggs are actually placed. This requires handling of the turtle eggs at least once if not twice. Does this have any adverse effect on the eggs? From https://seaworld.org/animals/all-about/sea-turtles/care-of-young/ it looks like it can - "For most sea turtle species, undisturbed nests can have more than 90% of the clutch successfully hatch. Nests disturbed by humans or animal predators tend to have a 25% or even much lower success rate." For your product contract, you have a spec to cool the sand to 27 degrees. It would be good to specify at what depth.