Q:

How to inflate/deflate to create artificial lungs

I'm trying to create lungs for a project I'm working on that can inflate and deflate. I'm quite new to EE and using the Arduino, so I don't have much experience to know what would be the best way to mimick lungs.
I saw this video and wanted to do something almost identical to create the lungs. (Weird video, I know.) Around 1:34 he shows how he created it. I did some searching to figure out how he did it, and I found something called "pneumatic actuated muscles". I'm not really sure how this is done though, I just saw what it looks like once it's done.
I'll be using a Lilypad Arduino to control the lungs since I'll be sewing it onto a shirt. That said, it would be great if the hardware to inflate/deflate the lungs could be light so as not to stretch the shirt when one is wearing it.
Suggestions? It could be a really small amount of air, too. I don't mind as long as it can slightly mimic a pair of lungs.

A:

You could just use a couple of servos and have them inside a bellows like structure. 
The servo movement would expand and contract the bellows.
It would look like the bellows/lungs are inflating/deflating.
No need for complex air seals.

