Introduction: How to Make Really Cheap Pressure Sensors

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About: Hi! I'm Isaac. I'm an 18 year old maker that can't keep my hands still. I aspire to show all other young people out there that you can be a great maker, no matter how old you are.
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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.

Supplies

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

Step 1: Tape

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.

Step 2: Bars

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.

Step 3: It All Comes Together

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.

Step 4: How to Use It

Connect alligator clips to the exposed tape on either end, and if you connect an LED and a battery to it like so, if you press down on the sponge, it'll light up!

Step 5: Adjusting

All you need to make the sensor more sensitive is a bit of cardboard. If you take a piece of cardboard and glue it on like this, and THEN cover it in tape, and then glue the sponge down to the cardboard, it makes the sponge way more sensitive, sensitive enough to detect a dropping object, or even better: A drumstick! (I don't have a drumstick, so bear with me and my screwdriver).

Step 6: End

Now you have your very own pressure sensor for use in Makey Makey projects and in simple circuits, and it didn't even cost you anything!
Thanks for reading this instructable. It was lots of fun figuring out how to make everything work, but it was worth it.
Bye!