Flexible display panel, flexible display device and deformation detection method thereof

A flexible display panel, comprising:

• a flexible substrate;
• a display device positioned on one side of the flexible substrate;
• and
• a piezoelectric sensor positioned on one side of the flexible substrate, wherein the piezoelectric sensor comprises a first electrode, a second electrode, and a piezoelectric layer positioned between the first electrode and the second electrode;
• and the piezoelectric sensor is configured to generate an electrical signal under an action of stress produced by bending the flexible display panel;
• wherein the first electrode is positioned on one side facing away from the display device, of the piezoelectric layer;
• and a section of the first electrode has a concave-convex shape, wherein the section is perpendicular to an extension direction of a bent axis of the flexible display panel;
• wherein the flexible display panel further comprising:
• multiple heightening layers arranged at intervals on one side facing away from the piezoelectric layer, of the first electrode;
• and the heightening layers coincide with convex areas of the first electrode towards one side of the piezoelectric layer.