Wear detection of candidate MEMS/NEMS lubricant films using atomic force microscopy-based surface potential measurements

The wear of a perfluoropolyether lubricant applied on silicon was investigated using atomic force microscopy-based surface potential measurements. An increase in surface potential is attributed to the change in the work function of silicon after wear and electrostatic charge build-up of debris in the lubricant. Thermally treated coatings containing a mobile lubricant fraction (i.e. partially bonded) were better able to protect silicon from wear compared with the fully bonded and untreated coatings. This enhanced protection is attributed to lubricant replenishment. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.