Monitoring chemical and physical changes on sub-nanogram quantities of platinum dioxide

We have measured in real-time the chemical reaction-induced weight loss and variation in physical and mechanical properties of sub-nanogram quantities of deposits utilizing the resonance response of microcantilevers. The hydr ogen reduction of sub-nanogram quantities of alpha platinum oxide deposited on micromachined silicon cantilevers and resultant weight loss, as well as the kinetics of this process, were investigated. Comparison with theory su ggests that this technique could be a powerful tool to measure physical and chemical changes occurring on sub-nanogram deposits. (C) 1999 Elsevier Sci ence B.V. All rights reserved.