Self Destructing Drive

Okay I recently managed to get a few hard drives, what I really have been wanting to do is make a self dustructing drive. I have done some thinking about it, and I would perfef if the ammount of damage done was limited to the drive its self, so no gun powder or thermite. I was condering somthing like a electro mag that I could put inside the drive case to wipe the bastard.

So anyone have any suggestions?

Put something REALLY important and irreplaceable on the hard drive. Even better if it is school related. Sit back and watch meltdown.

That always seems to destroy my hard drives.