Do CCD or CMOS chips get "tired" and lose image quality?

[tscheezy]

I have a Digital Elph S330 that I have taken many thousands of great pics with. Over the past year I have noticed the pics are becomming increasingly noisy/grainy, unsharp, and perhaps contrasty. It is hard to pin down, but whereas I used to be very impressed with the results, now I am often disappointed at the shots even taken in bright light with a steady hand.

I know my way around the camera and the settings are the same as way back when (no weird ISO dialed in, I'm not in the wrong white balance setting, the lens is clean, etc). The camera functions the same otherwise, but the pics are just starting to suck.

Do the CMOS or CCD image capture chips get tired or wear out over time? Some sort of pixel death going on like in old screens? Do they have a useable lifespan?