Shape Memory Effect of Four-Dimensional Printed Polylactic Acid-Based Scaffold with Nature-Inspired Structure.

The four-dimensional (4D) printing is an evolving technology that has immense scope in various fields of science and technology owing to ever-challenging needs of human. It is an innovative upgradation of 3D printing procedure, which instills smart capabilities into materials such that they respond to external stimulus. This article aims to investigate the feasibility of 4D printing of polylactic acid (PLA)-based composite scaffolds fabricated by incorporating four different nature-inspired architectures (honeycomb, giant water lily, spiderweb, and nautilus shell). The composites were developed by adding 1, 3, and 5 wt.% of Calcium Phosphate (CaP) into PLA. Various thermomechanical tests were accomplished to evaluate the properties of developed material. Furthermore, the shape memory characteristics of these scaffolds were examined using thermally controlled conditions. The characterization tests displayed favorable outcomes in terms of thermal stability and hydrophilic nature of the PLA and PLA/CaP composite materials. It was found that the honeycomb structure showed the best shape memory and mechanical behavior among the four designs. Furthermore, the introduction of CaP was found to enhance mechanical strength and shape memory property, whereas the surface integrity was adversely affected. This study can play a vital role in developing self-fitting high-shape recovery biomedical scaffolds for bone-repair applications.