How to Make Really Cheap Pressure Sensors

I've been hooked on making switches from common household items lately, and I decided to make my own pressure sensor on a budget from a few sponges I had lying around. The reason this is different than other versions of budget pressure sensors is that this one can be used more roughly and is nice and soft, because most of it is a sponge (meaning you can step on it and such)! This design is also easy to alter to make it more or less sensitive, and I'll show how that can be useful later on in the instructable.

You'll need:
- Conductive Maker Tape I got from Brown Dog Gadgets - It sticks to the sponge really well, and is more responsive than other materials I tested, but you could use copper tape if you wanted.

- A sponge
- Cardboard
- A hot glue gun
- Alligator clips
- LEDs

Cover the shown areas of the sponge and cardboard as shown. Note that the sponge has 3 strips of tape instead of two! This will make sure that the tape makes contact easier, and help the pressure switch work better.

Now, take 2 pieces of cardboard and lay them across the sponge at the top and bottom, like this. This is the material that will keep the pieces of tape from constantly making contact with each other.

Now, you can take your 2 pieces and glue them together! Make sure the tape lines up like in the picture. Then, glue the 2 bars of cardboard to the big rectangle, and it should look something like the second image. Note that you can see a slight gap separating the 2 chunks of conductive tape.