Designing an affordable, low-power solution to provide ventilation within a black soldier fly cultivation machine.
MIT D-Lab class
D-Lab: Design (2.722J / EC.720) - Spring 2025
Country
Taiwan
Team
- Olivia Rivera ‘26 - Undergraduate mechanical engineering major at MIT concentrating in product design
- Emma Scott ‘26 - Undergraduate mechanical engineering major at MIT
- Joel Santiago-Baretti ‘26 - Undergraduate mechanical engineering major at MIT concentrating in product design
Community partner
Stonbo Creative, Professor Stone
Problem
Our project is focused on designing a mechanism to add to Professor Stone’s existing bug cultivation machine that will provide consistent ventilation for the bugs throughout their growth cycle. Professor Stone made this device as a way to promote wasted reduction by feeding animal waste to the bugs as they grow and then in turn, using the larvae as feed for the animals. Professor Stone currently relies on manual hand mixing to ventilate the bugs and stop them from overheating during their growth cycle. Because the target demographic for this machine is farmers, users of this machine won’t have time to manually mix the thousands of bugs that are growing each day multiple times a day. Additionally, the bug cultivation machine is designed as a tower consisting of 15 circular trays in which each tray is divided into 10 grids. The large volume of grids meant that we needed a simple solution that wouldn’t dramatically increase the cost of the machine.
Design process
After speaking with Professor Stone and interviewing others, including an entomologist, to gather more information on bug rearing and the exact issues with ventilation, we recognized that the best solution would be something inexpensive, low-power, and adaptable to the current design of the machine. We researched ploughs and other geometric shapes that might initiate a rotating mixture when pushing the bugs. However, after testing numerous passive attachments, we came to the conclusion that landing on something passive wouldn’t work, given our analysis and testing. This was mostly due to the constraints in which parts of the machine were moving relative to other parts. Switching to an electromechanical solution, we modeled our prototypes after a water wheel. The best-performing prototype turned out to be a 5-spoke water wheel with spokes shaped like curved fingers to simulate the motion of hand mixing.
Proposed solution
Our design includes three components: a high-torque and low speed motor, a 5-spoke water wheel, and a piece of wood that attaches the assembly to the cultivation machine. With this solution, every other grid in each tray of the machine will be mixed. This means there would be a total of 5 motorized mixers per tray in the machine. Because we don’t have access to black soldier fly larvae, the next steps would be for Professor Stone to test this design in his machine and choose an appropriate motor for the torque needed to mix the bugs. We recognize that the volume of motorized mixers necessary for the number of grids in his machine is less than ideal and other paths can be explored to reduce the volume of attachments needed for mixing in the future.
Contact
Ankita Singh or Eliza Squibb, Co-Instructors D-Lab: Design
