Vine Tendril-Inspired Cold-Programmable Shape-Memory Polymer Composites Using Sugar Beet Pulp

Stimuli-responsive morphing in natural organisms enables dynamic adaptation to environmental challenges. Inspired by this, shape-memory polymers (SMPs) can undergo controlled shape transformations under external stimuli. However, conventional SMPs, typically constructed by uniform material networks, require heat-assisted programming to secure temporary shapes, which restricts their adaptability. By contrast, cold programming, deforming materials into a temporary shape without thermal activation, offers greater versatility but demands stringent material design. In this work, inspired by vine tendrils whose specialized cells enable asymmetric deformation (manifested macroscopically as coiling) under force, and motivated by the sustainability imperative of bio-derived materials in reducing dependence on fossil-based resources, we developed cold-programmable shape-memory polymer composites (SMPCs) incorporating bio-based sugar beet pulp (SBP). Through a magnetically assisted technique, heterogeneous domains were constructed within the SMPCs: a formulated SMP-rich region serving as the shape-stabilizing phase, and an SBP-enriched domain with a rough morphology enhancing mechanical resilience. After being stretched, the SMPCs underwent asymmetric recovery, enabling controlled actuations. This work highlights the potential of cold-programmable, deployable structures to advance smart material functionality while providing a sustainable pathway via bio-based components for emerging aerospace and soft robotics applications.