What a week! These past couple of days have been exciting to say the least.
Dr. Wettergreen came in for a prototyping workshop and gave us great feedback on our designs and helped point us in the next direction. He brought up the true lesson of the spaghetti noodle-marshmallow challenge (a design challenge presented to ENGI 120 students) which was to build under existing constraints. For the marshmallow challenge, the trick is to test continuously throughout the building process by placing the marshmallow on the structure while creating the tower instead of waiting until the very end to test it. For us, this meant that our next iteration would need to be designed to be submersible in saline.
The day after, we had midsummer presentations where we gave an overview of our work for the past three weeks. Afterwards, we had a client interview where we had the chance to update them on our progress and our prototypes. The THI team liked the track system for the vertical motion but also directed us away from the rocking motion and suggested trying to create a motion of a sine wave inside a sine wave, with each sine wave representing the individual heart and lung motions of different amplitudes and frequencies, with the coupled waves representing the cumulative motion.
We had our work cut out for us and launched into adjusting our prototypes.
Following Dr. Wettergreen’s advice, I constructed a functional prototype out of K’nex and PVC that could be pulled up and down under saline. Kaitlyn continued to work on the Arduino code while Sam and Chris explored another possible direction using solenoid coils.
The next steps I took involved a lot of CAD in SolidWorks. I had no experience with Solidworks or any CAD software (excluding a Fusion 360 workshop presented by Magdah) so I definitely struggled initially. With plenty of help, I became more familiar with the software and by the end of Monday, I was able to 3D print a track system involving concentric tubes with a notch to prevent the “inner tube” from slipping out. Thankfully, there were no huge problems with the design, but I did have to adjust some heights and dimensions. Additionally, I had to take one of THI’s existing designs and adjust it so the entire setup would not exceed the maximum height.
Like I said, it was a jam packed week.
Thankfully, we also had some time for relaxation and even a special surprise by the TA’s – catered lunch from Tiger Noodle House <3. Some of the interns also got together for a fun game of sand volleyball which was a blast.
Until next time,
Rachel Lee