Laser-Direct-Writing Reversible Aligned Wrinkling on Arbitrary Films Assisted by a Detachable Assembly Strategy

Dynamic oriented wrinkling especially on arbitrary film materials is highly desirable yet remains a great challenge. Here, fabrication of programmable aligned wrinkling patterns on different film/substrate systems via a laser-direct-writing (LDW) method is reported, regardless of photofunctionality and transparence of the target films. The key is related to smart introduction of photothermal materials (PTMs) into compliant substrates and even as an independent attachable/detachable layer assembled underneath the film/substrate systems. Experiments and theoretical modeling reveal that with the help of the photothermal effect of PTMs, in situ LDW-induced localized dynamic anisotropic stress field is responsible for the intriguing LDW path-parallel aligned wrinkling. Furthermore, dimensional analysis is carried out and explicit solutions quantifying the connection of wrinkling morphology parameters with the LDW conditions are derived for the first time, which enables theoretical pattern designing. It is highlighted that the attachable/detachable assembly strategy for the independent PTMs layer endows arbitrary film/substrate systems with on-demand photosensitivity when needed, which has been inaccessible previously. As demonstrated, these dynamic oriented wrinkling systems have found broad applications especially in smart soft photonics, e.g., information storage, anticounterfeiting, and responsive optical devices.