What sensors do I need for a teddy bear that can be pressed to play sounds?

Hi guys and girls,

My brother just got a baby girl, and I was thinking of making a teddy bear that can be pressed in various areas to play sounds that I would have pre-recorded. I live very far away from my niece, so this could be a way for her to hear my voice until I meet her hopefully sooner than later.

I was thinking I could use an Arduino with a Wave Shield. This one actually: Audio Shield for Arduino That way I can store the music on a SD card. People could change the card and put in their own stuff if they want.

What kind of sensors should I use to detect when the toy is being pressed?

These folks use plain tactile pushbuttons...
http://www.soundexpressiongreetings.com/musical-greetings/squeeze-button-sound-chips.html

But it does not seem like they would work that well.

I would try a force sensitive resistor. Round Force-Sensitive Resistor (FSR) [Interlink 402] : ID 166 : $7.00 : Adafruit Industries, Unique & fun DIY electronics and kits
The Wave shield is a good choice. I have used it before. I did a sort of similar project last year with a sheep toy. Sheep Doorbell | Electric Projects

hehe cute project. Like pauly says, force resistor would probably be a good one, though it might be a little small/take too much force for the baby to activate if you dont set its circuit right.

If your fine with going on the ghetto a bit and building your own buttons. this guide

might actually be pretty good. the buttons would be soft enough that a very young baby could definitely trigger them (just depends on how thick/thin the cloth you put between is). And you could easily customize the size of them as you need. Biggest problem I can see with making a button like this guy did though is that after a while if used a lot, the button would breka down (though ones in kids toys break like nothing anyways). Next i could see that the button might be pressed, but stay stuck down.

Thanks for the tips guys. I'm checking out your ideas.

I also thought of using a flex sensor somehow. Perhaps I could put it through the body so when the toy is deformed it triggers the sound. 404 ERROR

Another idea I just had was to place a light sensor under the arm pit in such a way that a resting bear would cover the sensor, but when the arm is raised light would trigger it.

Flex sensors could also work.

One word of caution. I almost started a project like this but droppped it due to babies putting everything in their mouth and it had lots of small parts.
I suppose the baby could use it only when "supervised".

That's a good point Pauly! I have to study baby toy history.