# How come rough mouse pads provide less friction?

Gaming mice have very smooth bottoms, but gaming mouse pads have a very rough surface, much more than regular mouse pads.

How can it be that a smooth surface on a rough surface has less friction than a smooth surface on a smooth surface?

If the surface of the mouse pad was also very smooth, this would create a lot of intimate contact between mouse and pad. This, depending somewhat on materials used for both surfaces, could lead to quite high friction coefficients.

Of course a rough mouse surface in combination with a rough mat surface wouldn't work either, as the surfaces would interact much like $$\text{Velcro}$$ does.

The combination of smooth mouse and rough mat is ideal because the smooth mouse can 'ride' smoothly and effortlessly over the peaks of the mat's surface, with minimum surface area contact.

Choice of the right material is however as important as surface texture: low friction coefficient materials are preferred.

• That's clever! Who comes up with such ideas? – Noam Sep 18 '19 at 17:28
• Clever material development engineers! ;-) – Gert Sep 18 '19 at 17:33
• Thanks. Corrected. – Gert Sep 29 '19 at 17:29