Double Functional Piezoelectric Film Based Stretchable and Flexible Acoustic Emission Sensor with Unique Magnetic Repulsion Sensing Enhancement and Contact Force Self-Detectability

This paper presents a stretchable and flexible acoustic emission (AE) sensor composed of patterned double piezoelectric-film foils and magnets along with stereolithographic structures. The proposed device has following novelties. The piezoelectric sensing structures with magnetic repulsion for effectively AE signal coupling enhancement. The lower piezoelectric serpentine-shaped AE detection structure with stretchable and flexible characteristics allows sensing versatile curved surface. Additionally, the contact force between the sensing target and AE sensor can be evaluated via monitoring the structure characteristic change of the upper piezoelectric structure of the AE sensor. The developed AE sensor could open a new field for versatile applications.