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Dechorionator

The dechorionator is a device that removes the protective chorions from embryos, namely Zebrafish embryos. The process for dechorionataion, without going into too much detail, is to add a protein to a dish of embryos, move them in a circular jerking pattern (carefully tuned), and then rinse the protein out of the dish. This whole process is very carefully done as the embryos are very fragile. Previously at SARL, the researchers had commissioned an engineer to design a device that could perform this function in a way that was more repeatable and with a lower mortality rate than having them do it by hand. The result was a device that worked, but was very expensive and bulky. Thus, the engineering group was tasked with redesigning the unit to be more cost effective and to have a smaller footprint.

To accomplish this, I found a much cheaper scientific shaker unit by the company ELMI and designed a replacement controller to allow it to perform the functions we needed. The very first revision of the PCB worked, which was a rare occurrence, and I assembled it in house using hot air reflow tools. To perform all the necessary functions, a liquid pump was added to the unit and my coworker Dylan designed and had cnc’d a plate for the top of the unit to hold the dishes as well as a distribution plate to get water to each dish. As I had many other projects to work on, most of the embedded programming went to my other coworker, Aaron, though I spent many hours helping him design and debug what became the final firmware.

In the end, we ended up with the product you see above, which easily cost a fifth of what the previous generation did. After many many hours of tuning it now matches the efficiency they were looking for, and takes up so little space in comparison that we can fit two units in the first generation’s place.