Acoustic Emission of Tape Peeling

The screening sound of tape peeling is a common yet annoying noise. Despite years of research, the reason has been hard to pinpoint. In this study, we reveal that the acoustic emission is produced by a series of weak shock waves generated by the fine dynamic transverse fractures during the slip phase. Each acoustic pulse occurs when the fracture tip reaches the edge of the tip, which is confirmed by using two microphones synchronized with two simultaneous high-speed cameras. One captures the fracture motion in the adhesive through the transparent substrate during detachment, while the other employs Schlieren imaging to observe the weak shock waves in the air.