My original goal of creating a robot that inflates and deflates so it can float and sink in water has unfortunately failed. I got my Arduino Uno to work, but my Arduino Pro Mini inexplicably doesn’t run despite being connected in the same way, my soft mold got stuck to the the rubber, & I found out too late that I was using the wrong type of over the air signal. That being said, I experimented with a different idea, and I’m posting it here in case any future team wants to give it a shot.
Creating a robot that floats using compressed air seems very easy. I bought compressed air, the type that’s used to clean keyboards, & inserted it into a big balloon.
With just that, the balloon floats very easily without air, so I wouldn’t worry about any robotics components being too heavy :
I put a bunch of weight into the balloon to make it sink:
Here you can see that a minimal amount of air gets the balloon to float again:
To automate this, you need to some Arduino that can squeeze the pump when it receives a radio signal. I used infrared for my project and later found out that it doesn’t work well in water.
The difficult part would be figuring out how to remove the air without letting water back in.