Multifunctional shape memory polymer composites: laboratory to reality via additive manufacturing

形状记忆聚合物（SMP）可以存储临时形状，并且在施加外部刺激（例如热）时恢复其原始形状。SMP提供优于其它形状记忆材料（例如形状记忆合金）的重要优点。这些优点中的一些是重量轻、相对较高的应变恢复能力、更容易定制的性质和可制造性。它们具有巨大的应用潜力，例如无人驾驶飞行器（UAV），变形飞机部件和生物医学支架等。在其更广泛的应用的瓶颈是其固有的低机械性能和形状恢复力（SRF），以及在实际的“现场应用”作为一个功能的湿度，温度等，这些重要的方面需要加以解决和详细记录的关键应用程序，这是我们的研究计划的建议背后的主要动机。 大多数SMP受湿度的影响;因此，我们进行了详细的研究，以确定其对SMP的影响。此外，我们研究了打印参数对使用基于挤出的增材制造（EBAM）技术打印的SMP的性质的影响。SMP复合材料（SMPC）是SMP的增强体，与SMP相比具有更高的力学性能和SRF。我的团队多年来一直致力于EBAM技术生产的多功能SMPC的生产和表征。根据我们积累的知识和专门知识，本提案旨在解决上述不足之处。 拟议的研究计划的主要目标是：（a）生产和表征纤维增强SMPC使用EBAM;（B）开发一个模型来预测SMPC的性能;（c）生产SMPC集成加热元件，以促进现场激活，并调查电阻的加热元件的结构健康监测（SHM）能力。 所提出的计划的新奇和意义源于它的承诺，提供了一个强大的分析和实验的理解SMPC。这将提供一个大型的实验数据库，不仅为这个计划，而且为研究人员和工程师，与SMPC的工作在未来几年。该分析模型将是一个简单而准确的模型，不幸的是，目前在文献中缺失，并打算在该领域的开拓性工作。所提出的活化技术和SHM能力将使这些新材料成为真正的多功能SMPC。因此，该提案将提供一种前进的方式，通过促进SMPC在上述战略关键应用中基于科学知识的使用，将这些材料从实验室带到实际的现场应用。该计划将为加拿大和世界各地的知识进步做出重大贡献。

Shape memory polymers (SMP) can store a temporary shape and restore their original shape upon application of an external stimulus, such as heat. SMP offer important advantages over other shape memory materials, such as shape memory alloys. Some of these advantages are lightweight, relatively higher strain recover-ability, easier tailorable properties, and manufacturability. They have the great potential to be utilized in applications, such as unmanned air vehicles (UAV), morphing aircraft components, and biomedical stents, to name a few. The bottleneck in their broader utilization is their inherently low mechanical properties and shape recovery forces (SRF), and a fundamental understanding of their properties in actual “field applications” as a function of humidity, temperature, etc. These important aspects need to be addressed and documented in detail for critical applications, and this is the main motivation behind this proposal for our research program. Most SMP are affected by humidity; therefore, we conducted detailed studies to identify its effects on SMP. Additionally, we studied the effect of print parameters on the properties of the SMP printed using extrusion based additive manufacturing (EBAM) technique. SMP-composites (SMPC) are reinforced SMP and have higher mechanical properties and SRF compared to SMP. My group has been working towards production and characterization of multifunctional SMPC produced by EBAM technique for a number of years. Building on to the knowledge and expertise we have developed, this proposal is prepared to address the aforementioned shortcomings. The main objectives of the proposed research program are: (a) to produce and characterize fiber reinforced SMPC using EBAM; (b) to develop a model to predict the properties of SMPC; (c) to produce SMPC with integrated heating elements to facilitate field activations, and to investigate the resistance of the heating elements for structural health monitoring (SHM) capability. The novelty and significance of the proposed program originate from its promise to provide a strong analytical and experimental understanding of the SMPC. This will provide a large experimental database not only for this program but also for the researchers and engineers that work with SMPC for years to come. The analytical model will be a simple yet accurate model that is unfortunately currently missing in the literature and intended to be a pioneering work in the field. The proposed activation technique and SHM capabilities will make these novel materials true multifunctional SMPC. Consequently, the proposal will provide a way forward to take these materials out of the laboratories to actual field applications by promoting scientific knowledge based use of SMPC in the aforementioned strategically critical applications. The program will make significant contributions to the advancement of knowledge in Canada and around the world.