4D Printed Butterfly-Inspired Hydrogel Structures: Simple Strategies for Multiform Morphing

Abstract

4D printing enables three-dimensional structures to respond dynamically to external stimuli, significantly expanding their functional potential. While most hydrogel-based 4D printing using femtosecond laser two-photon polymerization focuses on material functionalization and structural design, little attention has been given to achieving intelligent deformation by modifying the scanning strategy. Inspired by the layered architecture of butterfly wings, we introduce a novel approach to fabricate diverse convoluted deformation structures. By combining morphological and mechanical property analysis with a two-photon one-step 4D printing strategy, we demonstrate precise control over deformation behavior. Furthermore, we showcase the ability to fabricate customized deformation structures on demand employed for actuation and sensing by adjusting scanning methods. This simple and flexible one-step 4D printing method represents a significant advancement in micro- and nanoscale sensing and fabrication, offering new possibilities for responsive hydrogel systems.