Friction in MEMS-scale devices is troublesome because it can result in lateral stiction of two sliding surfaces. We have investigated the effect of modulation of the normal force on the friction between two sliding MEMS surfaces, using a fully MEMS-based tribometer. We have found that the friction is reduced significantly when the modulation is large enough. A simple model is presented that describes the friction reduction as a function of modulation frequency as well. Using this technique, lateral stiction-related seizure of microscopic sliding components can be mitigated. (C) Koninklijke Brill NV, Leiden, 2010