Irregularities present on a surface are often described as surface roughness or texture. These surface textures such as grooves and dimples impart friction, which is the force between two sliding ...

With the help of a magnetic fluid, researchers have designed surfaces with tunable friction, allowing them to control the movement of liquid droplets and other particles. Such surfaces could enable ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Friction is a force that exists when two surfaces rub up against each other. For example, this cup on ...