After a couple of gearing and sizing issues, the chalmy team was able to fix the spin of the reactor. Now, we have a functional, reliable, and sustainable rotation for the chalmy bioreactor.
A current model redesign has been uploaded to the Assignments section of the website under the name "Module 54 redesign." This has all the updated plans and diagrams for the Chlorella bioreactor.
The gaskets that we are using for the bioreactors are composed of a silicon-based material. We decided to test the material to see how much it can compress and if it ever loses its integrity. This test was fruitful as we tightened the screws extraordinarily tight and the gasket held up. This is important because we need to ensure that the gasket can form a tight, reliable seal aboard the ISS.
Above is our Chlorella bioreactor, sealed with liquid inside. The bioreactor is rested on its side to fully test the strength and durability of the motor. From this test, we learned that the bioreactor rotation is fully functional and sustainable. Also, this allowed us to test for leaks, and none were present.
Also, we apologize for the sideways picture. We are unable to rotate the file using the school's technology.
Over the past couple of weeks, we have finalized our designs and are currently putting everything together. We are finishing up the soldering for the primary and secondary NESI boards. Also, we are assembling the final bioreactors. Now, only small adjustments need to be made such as focusing the camera and loading up the bioreactors with algae.
These upcoming days are going to be intense. We are scheduled to ship the bioreactor Tuesday, April 21. By tomorrow, we are planning to have the entire bioreactor assembled, loaded up with algae, and placed in the space box. We will conduct a full test of this weekend; this will include the code, algea, lights, and everything else in the experiment. This weekend-long test will help us identify any last-minute problems and allow us to come up with swift solutions.
In our continued effort to maximize the sealing of the bioreacter, we have decided to increase the width of the walls of the quadrants. This increase in width will increase the surface area where sealant can be applied, thus increasing the sealing of the lid.
We are currently scaling down our entire Chlorella bioreactor. We are decreasing the size because we wish to minimize weight, decrease area for potential leaks, and leave room for possible last-minute additions. Also, by shrinking the bioreactor, our motor will have a stronger rotation and our camera will be able to take wider pictures. We are not decreasing the size by much - just enough to make a small difference.
We want to be able to test the strength and durability of the helicoils. Therefore, we designed a part to test the helicoil strength (below). The plan for this part is to have the X inside the lid of the bioreactor. Then. the protruding 2 cylinders will hold a 5-pound weight. This weight will apply force downwards on the bioreactor and thus testing the strength of the heliciols. We need to ensure that our helicoils are secure and reliable.
In effort to tighten the seal on the bioreactor, the hardware team has decided to increase the amount of helicoils on the bioreactor, from 4 to 8. Hopefully, this will tighten the connection between the bioreactor segments, thus increasing the seal. A better seal will prevent future leaks. Also, we learned that the hydrogen-detecting tape works in the solution. Therefore, it was unnecessary to have the inner ring compartment. Thus, we took the ring out.
The class just came back from Spring Break. During the break, we conducted a couple experiments to test the bioreactor models. We put both strains of algae in their respective bioreactors and simulated the experiment over a week-long span.
One immediate observation we noticed is that once the solution was added to the bioreactor, it was much heavier than anticipate. It was so heavy that the bioreactor was unable to spin. After much effort, we were unable to fix the problem before break. Therefore, for the experiment, we manually spun the bioreactor to simulate the motor spin.
The first couple of days were successful, however, the algae soon began to leak out of the bioreactor. First, only one quadrant would fail until eventually the whole bioreactor leaked. We are currently devising solutions to improve the spin of the bioreactor and the sealant.