Flexible Shape Memory Structures with Low Activation Temperatures Through Investigation of the Plasticizing Effect

This study developed thermoplastic polyurethane (TPU)–polylactic acid (PLA)–polyethylene oxide (PEO) shape memory polymer (SMP) composites with tunable activation temperatures suitable for biomedical and smart structural applications. Adding PEO as a biocompatible plasticizer decreased the glass transition temperature (Tg) of the TPU/PLA blend from 62.4 °C to 34.6 °C, enabling shape recovery at near-physiological temperatures (37 °C). Bowtie honeycomb geometries fabricated from the blends achieved 86.5% shape recovery at 37 °C with 30 wt% PEO, only 5% below recovery at 50 °C, while preserving structural integrity. The study highlights the potential of PEO-plasticized SMPs for biomedical implants, deployable devices, and self-sensing structures.