This article describes a study of the static friction and wear of coated microelectromechanical systems (MEMS) surfaces using thermally actuated friction microdevices. In order to characterize static friction and wear, a tribological deep reactive ion etched silicon test microstructure is developed. Reproducibility of the data is proven by testing multiple devices in parallel. Conformal coatings consisting of atomic layer deposited (ALD) TiO2 or ZrO2 and successive ionic layer adsorption and reaction (SILAR) deposited MoS2 or ZrO2 films are applied on the MEMS silicon test devices. The effect of film roughness and humidity on friction and wear is studied by exposing the coated MEMS devices to a relative humidity varying between 5% and 100%. The coatings were found to behave differently, ZrO2 and MoS2 decreasing the coefficient of friction compared to uncoated devices, while TiO2 presented a decrease in the coefficient of friction only at higher humidity. The wear data for the ALD coated devices, quantified from the point of view of "debris creation" and stability of the friction coefficient, indicate much improvement over native oxide coated silicon devices, while the SILAR coatings showed high wear. (c) 2005 American Vacuum Society.