Last summer, a good friend of mine from the Biochem department approached me for some help. He was conducting some research that involved studying the response of certain bacteria to various level of Far Red light. They needed a setup where one could embed multiple test tubes, each exposed to a different intensity of light.
The electronics I felt was the easy part, and it was the actual design of the incubator that was alluding me. I wanted to design something minimal but mass reproducible if required. At first I thought I could laser cut, glue and paint a stacked tray like arrangement. But again, this was not too elegant as it would involve forming multiple parts together. It then occurred to me that almost all University labs have access to 3D printers. Using one would also mean I could print the whole fixture in a few parts!
So I sat down and thought of a design and eventually settled with this:
The base accepts a custom PCB that hosts the various LED and circuitry. The whole incubator can be printed as 2 parts. I broke it into 3 because my printer is rather small.
The circuit was a simple string of LED controllers with 10 turn pots for simple control (i was asked to keep it simple and add the pots as opposed to some fancy digital control)
Finally after hours and hours of printing, the finished product looked rather nice: