The Artificial Pancreas doesn't work

[rosa52]

My daughter built an artificial pancreas for her science fair project but cannot get the pump to work. What could be the possible cause? I attached pictures of it below. Need help ASAP. Thanks in advance



[Administrator note: project directions: https://www.sciencebuddies.org/science- ... #procedure ]

[deleted-70304]

This can be a complicated project to troubleshoot. It will help if you can provide a (clear and close) photo looking down at the breadboard so that experts can clearly see the circuit your student has set up. (The photos you've attached don't give a clear look at the breadboard elements.)

Any information you can provide about what is happening (or not happening) will also help.

Amy
Science Buddies

[deleted-70304]

In addition, make sure your student has gone through the troubleshooting FAQ on the "Help" tab. The first question there is related to the pump, but the whole file contains important information.

Q: The pump will not run. What should I do?
A: If your pump is not running at all, there are several troubleshooting steps you can try:
Double-check your circuit to make sure that it matches the breadboard pictures and descriptions from the Procedure exactly (in the "Assembling the Circuit on the Breadboard" section).
Make sure all of your jumper wires and other components are pressed firmly into the holes of the breadboard.
Make sure your batteries are properly inserted into the battery pack.
One at a time, turn the potentiometer all the way clockwise and then all the way counterclockwise.
If none of the above steps work, try putting fresh batteries into the battery pack.

Amy
Science Buddies

[rosa52]

Thanks a lot. After looking at the breadboard, she realized she had the wrong potentiometers, so I purchased the correct ones. The pump is now working , however it does not turn off unless it's plugged out.

[deleted-70304]

I am glad she realized she had the wrong parts. (If you do want to post a closeup look at the breadboard, that will help experts look at the circuit.)

But has she carefully gone through the first part of the procedure under "testing"-- In that section:

In this part of the procedure, you will test your artificial pancreas model. You will do this by first normalizing it to a neutralized solution to make sure the pump will turn off once your solution is neutralized.

She needs to carefully work through those steps. Step 11 details adjustment of the potentiometers as part of this process.

The pump may start running as soon as you put the conductivity sensor in the neutralized solution, but do not worry if the pump is not running yet. (When the pump runs, vinegar should simply be pumped out of, and then back into, the "vinegar" bowl). In this step, you will normalize your artificial pancreas model so that the pump does not run in a neutralized solution, but still runs in a solution that is slightly more acidic (which will be more conductive). You will do this by adjusting the three potentiometers (the blue components with the white knob that you put in holes B12–14, B16–18, and B20–22).

(Full details are provided in that section.)

If you can let us know where she is in the process and what is happening, it will help Experts know where problems may be occurring.

Amy
Science Buddies