3D Printing of Smart Structural Composites by Thermoelectric Extrusion with Molecular Precision

通过分子精度热电挤压 3D 打印智能结构复合材料

• 批准号: 1463103
• 负责人: Vishnu Baba Sundaresan
• 金额: $ 29.98万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1463103&HistoricalAwards=false
• 关键词: 3D; Printing; Smart; Structural; Composites

A smart structural composite provides structural support with built-in sensing (temperature, pressure, flow and load) functionalities. Recent advances in intelligent infrastructure and the proliferation of wearable gadgets and smart prosthetics have created a need for manufacturing affordable, customizable, and precise smart structural composites. Among current manufacturing methods, 3D printing can directly build customizable parts from computer models, but lack the ability to incorporate additives (such as piezoelectric nanoparticles) that provide sensing functionality. Most polymer-based 3D printing methods build parts by layer-by-layer deposition of a polymer extruded out of a nozzle above its melting temperature and have limited control of the polymer microstructure as it cools down. This leads to poor dimensional accuracy of 3D printed parts in comparison with parts fabricated from traditional manufacturing processes. This award supports fundamental research to create new knowledge in 3D printing and its application in healthcare, education, and engineering will foster new economic activity. This award also supports participation of women and underrepresented groups in engineering research and outreach efforts by the investigators with middle and high school students.The objective of this research is to formulate relationships between an applied electric field during the extrusion of thermoplastic ionomer/piezoelectric composite and its resulting material properties (e.g., optical clarity, strength, piezoelectric strain coefficient, and interfacial adhesion between polymer matrix and nanoparticles). In a thermoplastic ionomer, the difference in polarity between the hydrocarbon chain and ionic group creates an electrostatic driving force and results in aggregation of ions. In this context, there exists a knowledge gap on the aggregation of ions in a thermoplastic ionomer above its melting temperature under the influence of an externally applied electric field. In order to understand how an electric field (greater than the electrostatic force of aggregation) applied to a mixture of thermoplastic ionomer/piezoelectric additive affects aggregation morphology (size, distribution in the matrix and around nanoscale additives), the research team will conduct experimental research and coarse-grained molecular dynamics simulations of a representative thermoplastic ionomer with piezoelectric additives (ethylene/methacrylic acid with PZT-5H and PVDF).

智能结构复合材料提供具有内置传感(温度、压力、流量和载荷)功能的结构支撑。智能基础设施的最新进展以及可穿戴设备和智能假肢的激增，产生了对制造负担得起、可定制和精确的智能结构复合材料的需求。在目前的制造方法中，3D打印可以直接从计算机模型制造可定制的部件，但缺乏加入提供传感功能的添加剂(如压电纳米颗粒)的能力。大多数基于聚合物的3D打印方法是通过将从喷嘴挤出的高于熔化温度的聚合物逐层沉积来制造部件，并且在冷却时对聚合物微观结构的控制有限。这导致3D打印零件的尺寸精度与传统制造工艺制造的零件相比较差。该奖项支持基础研究，以创造3D打印的新知识，并将其应用于医疗保健、教育和工程，将促进新的经济活动。该奖项还支持妇女和代表不足的群体参与工程研究，并支持研究人员与初中生的外展工作。这项研究的目的是阐明热塑性离聚体/压电复合材料挤出过程中的外加电场与其产生的材料性能(例如，光学清晰度、强度、压电应变系数和聚合物基质与纳米颗粒之间的界面粘附性)之间的关系。在热塑性离聚体中，碳氢链和离子基团之间的极性差异产生静电驱动力，导致离子聚集。在这一背景下，在外加电场的影响下，热塑性离聚体中离子在熔融温度以上的聚集存在着知识鸿沟。为了了解施加到热塑性离聚体/压电添加剂混合物上的电场(大于聚集的静电力)如何影响聚集形态(尺寸、在基质中和纳米级添加剂周围的分布)，研究小组将对具有代表性的含压电添加剂的热塑性离聚体(含PZT-5H和PVDF的乙烯/甲基丙烯酸)进行实验研究和粗粒度分子动力学模拟。