How tough is a sensor?

[rpcrowe]

This is not exactly scientific but, The results are surprising...

https://www.youtube.com/watch?v=xLzrS3aSJWE&t=433s

[Manfred M]

Not at all surprising. assuming that the top layer is glass. Also not at all scientific

Glass is mostly silicon dioxide; i.e. sand that has been melted. Glass is hard; it takes an even harder material like silicon carbide or diamond to cut it, so yes, a cheap knife blade is not going to scratch glass. Take a knife at a glass surface at home; a window or mirror and your get the same result. Glass is hard to scratch; that's why (in addition to being transparent) if finds so many uses like in windows and mirrors.

The downside of hardness is that the material is quite brittle, so blast it with something small and hard and you can chip it, rather than scratch it. A chip is as bad as a scratch. Take a look at a car windshield; after a few years of use with all those pieces of grit hitting it, the surface is full of tiny pits (and perhaps a few larger ones too).

Hardness also means low ductility, so press on it too hard and it will crack.

A sensor has a number of layers that make up the stack; the silicon substrate that is the actual sensor (also brittle), the UV and IR filters, the Bayer array and anti-reflective coatings. Lets on push too hard as these areas are going to be fragile as well. With these elements break or will the resin holding them together delaminate?

Nicely said, the test in the video is suspect. The sensor assembly is a precision part and while you may not scratch it or break it with rough handling, other types of damage can result. Let's put that abused sensor back in the camera and see if it still works and if it does, how well it still works...