Science Buddies: "Ask an Expert"

Hello! I have created the project, dealing with diabetes, road to building an artificial pancreas. I ask that you can help me figure out if I can program or make the pump automatically put the right amount of vinegar to the baking soda. For example, when I was turning the knobs, nothing happened . This caused the first test unsuccessful for I put too much vinegar in the baking soda which (in real life) is very dangerous which can lead to a hypo. I need to know what I did wrong so it will be a improvement for the project. Please respond quickly because the next science fair is in 3 week.

Thank you

Hi sciencenerd4,
Based on your description, I would suggest that you try adding a step where you first take a pH measurement of the baking soda, then dial in an approximate starting amount for the vinegar before turning on the "experiment." (You will need to probably do a different set of experiment to generate this "starting amount" table)

This method is a simplified version of transferring the initial condition to a PID (Proportional, Integral, Derivative) control loop. (Please google the term " Control Theory PID." I know there's a lot of math involved but it boils down to this:
When you do something, there's an error, you read the error, and then you adjust what you do.)

I hope this make sense. Please let us know if there's anything else we can do to help.
Good Luck!
Willey

Thank you so much!