Abstract: The bearing failure sensor includes a micromachined mechanical resonator h a conductive cantilevered beam mounted on a conventional insulating substrate to form a microchip. A conductive contact is mounted in close proximity to the free end of the conductive beam to form a gap. An integrated circuit is connected between the fixed end of the beam and the conductive contact. The microchip is mounted on a vibrating machine to be monitored. When vibrations having a given frequency and magnitude occur, the free end will vibrate and move sufficiently to close the gap completing a circuit and causing currents to flow that are detectable by the integrated circuit. Multiple resonators, having different gap sizes and natural resonant frequencies, may also be mounted on a single substrate to monitor vibrations at a plurality of different frequency and amplitude thresholds.