DIY PCR: 3D Modeling and Final Design
In the first part of the DIY PCR series I had shown a proposed model for the PCR machine. Before I went ahead with that design however I needed to validate it to ensure that the machine could do it’s job properly. With my friend Kush’s help we were able to do just that.
As an engineering student, Kush was able to bring a new perspective to the project. During our brainstorming sessions he also introduced me to a program called SolidWorks. SolidWorks is a program that allows for computer-aided design/engineering software. One of it’s numerous benefits is users are able to accurately model conditions like heat or air movement on projects.
After several meetings, you can see the results on the left. The heating mechanism didn’t change — we were still using nichrome wire. You’ll see however that the fan on the bottom is connected to a funnel of sorts. As Kush described it, by forcing the air through the funnel, the air being pushed out would be colder than the air coming in. This in turn would cool down the hot side of the peltier plate and allow for the cold side to remain cold.
While air flow modeling in SolidWorks looked to be effective I wasn’t quite happy. I felt that we could definitely make the design simpler. During a weekend project where I was taking apart some old PC’s I realized the CPU cooler would be a better alternative to our current updated design.
We also realized that we could simply switch the direction of the current in order to change which side of the Peltier plate was being heated or cooled. This meant that the fan for the CPU heatsink and the peltier plate could be controlled much more effectively with the Arduino.
Based on this info, the final design was complete!
Thanks for reading. The next steps will be to design the final circuit and then test it out by wiring everything up on a bread board. Stay tuned for that!
