Friction is one of the fundamental limiting factors in the design of MEMs devices.
It is instead, a dynamic phenomenon dependent on multiple parameters and exhibiting a range of physical behaviour. For example, there are molecular and polymere interactions including chain entaglements, electric charge buildups, temperature dependences, surface scratching, plastic deformations of crystals, stick and superkinetic sliding of lubricants and many other effects. Some of these effects have already been shown to exhibit classical dynamical systems behaviour such as bifurcations, loss of symmetry, and hysterisis. Currently, there are two techniques which address this inherint complexity. First, there is the emergence of experimental techniques which can measure friction on small length and time scales.