Why do smooth, glossy surfaces feel sticky to the touch but a slightly textured surface does not?
In: Physics
Molecules of your hand are attracted by molecules of the surface. This attraction is called Adhesion and every substance exhibits it.
In a smooth surface, there is more surface for the molecule to interact, hence more attraction. This makes smooth surfaces sticky.
The ridges and peaks in a rough surface prevent the maximum number of interactions to occur, making them less sticky.
In a nutshell,
Smooth surface, more ~~surface~~ contact area, more sticky
They may or may not. but..the same surface material that is rough or dimpled will have less surface contact, and therefore the degree to which it is sticky will have less total stick because less surface is touching your skin.
“smooth” is very relative, based on what light our eyes can perceive reflecting off the surface. Glass, for instance, is full of ridges and valleys if you zoom in far enough. Our fingers are also full of these ridges, visible as finger prints.
Every two surfaces in the universe interact uniquely when in contact with one another, and we quantify this with a derived constant, called the coefficient of friction. Without zooming in too far for this explanation, your finger experiences more friction when in contact with glass or another “smooth” surface, likely because there is more contact between the tiny ridges. The stickiness you’re feeling is most likely just friction.
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