Recently, a new cantilever-type vibration-based electrostatic MEMS energy harvester using potassium ion electrets was developed and fabricated. In order to investigate the sensitivity of the features generated by this energy harvester to specific bridge damage, three cases were studied herein: one numerical study on pier scouring, one laboratory experimental study on girder damage and support malfunction of a steel model bridge, and one rarely seen and highly valuable field experimental study on an incrementally damaged steel truss bridge.