Analysis of shape-memory polymer composites with embedded microvascular system for fast thermal response

The microvascular strategy demonstrates unique advantages in shape-memory polymer applications as it can achieve both rapid thermal activation and deactivation during a typical shape-memory cycle. In addition, localized overheating can be avoided in comparison with other heating methods, such as the magnetic and electric heating. In this paper, a finite-element-based computational analysis was performed to study the rapid thermal response of shape-memory polymer composites with an embedded microvascular system. We show that the polymer shape-fixing speed, the shape fixity after a given cooling time, and the shape-recovery rate are significantly enhanced due to the rapid cooling and heating effect of internal microvasculature. The effect of the composite dimensions and microvascular channel arrangement on the activation and deactivation was studied. Typically, reducing the composite thickness and tube spacing increases the shape-recovery speed of the shape-memory polymer composite by effectively reducing the length of the thermal conduction pathways. Strategies for achieving an optimized tube arrangement were also discussed based on the considerations of the system mass and thermal boundary conditions. The results in this paper provide a guideline for further designs and applications of shape-memory polymer composites with embedded microvasculature.