Brainstorming
At first, I tried to create a switch that works via static electricity. Attach a conductive tape to a piece of plastic bag and make it connect each end of wires when static electricity is applied to the switch. However, I soon realized that there are two major problems:
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- I need a lot of static electricity to effectively lift the plastic bag.
- A bit of wind can mess up the result.
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To resolve these issues, I could have tried a balloon with lots of physical/spatial constraints (such as a box) that limit the position and rotation of the balloon, but since large, delicate systems often lead to lots of errors, I decided build something smaller and simpler: a water sensor.
Overview
OverviewThe idea here is very simple. I arranged so that each end of wire is placed very close to each other but not touching. With the fact that tap water is conductive, I can activate the switch with a drop of water.
Operation
Of course, if the water is removed manually or through evaporation, the switch disconnects and the light turns off.
Possible Application
Because the circuit completes at the presence of water, it may be able to tell whether you should water the plant.