Driven colloidal monolayers: Static and dynamic friction

Trapping and dragging colloidal monolayers in two-dimensional optical lattices is offering the possibility to mimic friction between crystals (or even quasicrystals) visualizing directly the intimate mechanisms of sliding friction, with the additional possibility to change parameters freely, and to compare directly experiment with theory. Realistic simulations, which we review here, make a number of predictions about static features and dynamic sliding and reproduce well recent observations. Together, they provide a first demonstration of the potential impact of colloid dynamics in nanotribology