Smart Laser‐Writable Micropatterns with Multiscale Photo/Moisture Reconstructible Structure
Songshan Zeng, Yin Liu, Shuliang Li, Kuangyu Shen, Zaili Hou, Aimee P. Chooi, Andrew T. Smith, Zi Chen, Luyi Sun
Abstract
Abstract The design of a dynamic, versatile, convertible, and responsive micropatterned system is realized by a photo/moisture reconstructible multiscale film‐substrate bilayer structure. Specifically, a hydrophilic polyvinyl alcohol (PVA)/laponite (LP) thin film is covalently bonded to a photothermally active polydimethylsiloxane (PDMS)/carbon black (CB) soft substrate. A laser engraver can inscribe programmable aligned micro‐wrinkles by manipulating laser power and spatiotemporal control. These wrinkles can be modulated into three distinct systems 1) moisture erasable and laser re‐writable wrinkles; 2) moisture driven reversible wrinkles; 3) moisture resistant wrinkles, which are achieved by controlling a) the moisture resistance of PVA; b) the dimensional stability of PVA/LP film regulated by the LP nanostructure, which can be adjusted by the laser power and the LP ratio. This programmable system can be applied in information encryption/recording and as a moisture responsive electrical switch, offering new routes for the modulations and applications of next generation smart materials.