A test system has been assembled to examine factors controlling the reliability of microdevice switching. The system consists of a spherically tipped sputter-coated post driven by a piezoresistive actuator into a sputter-coated micromechanical membrane. Contact forces are calculated based upon the measured deflection of the micromechanical membrane, which is induced by post actuation. Membrane deflection is measured using white light interferometry. The known geometry of the membrane and probe tip permits the estimation of contact area and, hence, contact pressure. Preliminary testing of sputtered gold contacts resulted in localized melting, material transport to the membrane and failure of contact surfaces at relatively low contact pressures and current densities. Further testing will examine the factors governing the reliability of microdevice contacts, such as material properties, contact pressure and current density.