pressure/force sensor

Using Arduino Sensors
1

Hi,

I am looking for a sensor in my project.
I need to make a "tile" or at least something slim that detects when someone steps on it and when someone steps off.
The tile will be on the edge of a swimming pool so it has to be waterproof. A piezo in some tile would seem nice but I believe it doesnt really detect if someone steps of (its a knock sensor right?). I have made two of these already with just two aluminium plates that touch each other when the tile is stepped on, but they both broke easily. Do you know of a better way to do this?

Thanks!

2

Google mat switch. They are made to trigger motorizes doors and such. And waterproof.

3

You can use a force sensor like this one
http://www.ebay.co.uk/itm/like/220923421815?lpid=83&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=83&ff19=0

Or some force sensitive plastic like this

4

thank you both very much, I think I will make a mat switch

5