Extended Data Fig. 5: Proposed mechanism of the irremovable wrinkles by ICP post-treatment.

Schematic illustrations of evolution in wrinkles by ICP treatment. a, Wrinkles formed to release the high fstrain, along with the strong fcoupling. b, Partly released wrinkles when heated to 650 °C, with weak fstrain and strong fcoupling. c, Retained wrinkles after ICP treatment at 650 °C, with weak fstrain and weak fcoupling. d, Partly released wrinkles when cooling down, with stronger fstrain and weak fcoupling.