Study on reinforcement and repair of cracked piezoelectric materials

This study investigated the effects of strain and crack formation on the performance of piezoelectric materials as well as methods to repair damaged electrodes and reinforce the piezoelectric material. Specifically, this study investigated whether Ag paste (thickness: 0.1 mm) could restore electrical contact in damaged electrodes, and whether a coating of UV curable resin could provide reinforcement against crack formation. Experiments were conducted with a piezoelectric material on a steel cantilever substrate. The substrate was subjected to impact at various distances from the free end of the piezoelectric material to vary the applied strain. It was found that the output voltage increased with the strain (distance of impact from free end) until crack formation, which led to a large decrease in output. However, Ag paste could successfully restore electrical contact. Furthermore, before crack formation, coating with UV curable resin increased the maximum strain, and therefore, maximum electrical output, as well as cycle life.