Smart Laser-Writable Micropatterns with Multiscale Photo/Moisture Reconstructible Structure

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.

Automated summary

This research presents a dynamic, versatile, convertible, and responsive micropatterned system with the ability to reconstruct under moisture, suitable for information encryption and moisture responsive electrical switches.