Materials scientists are measuring the rolling friction of tiny, micrometer-sized particles. These measurements permit them to better understand everyday products such as concrete. For the first time, ...

1.1 What is friction? Take this everyday example: when a coffee mug rests on a flat table, the kinetic frictional force is zero. There is no force trying to move the mug across the table, so there is ...

For the first time, ETH Zurich Materials Scientists have measured the rolling friction of microscopic, micrometer-sized particles. These measures allow them to better understand common items like ...

Friction exists because most surfaces really look like this under a microscope. Note the hills, the crests and the valleys. These are called asperities, or material deformations. They occur on rough ...