EAGER: Fabrication and Characterization of 3D Ceramic-Coated Polymer Scaffolds

非技术描述：这个EAGER项目利用新的沉积技术，研究沉积在聚合物结构上的陶瓷膜的形成，以更好地了解陶瓷的组成和微观结构如何取决于沉积条件。这一信息对于通过在聚合物模板上涂覆陶瓷膜来制造三维陶瓷结构是至关重要的。三维陶瓷结构具有广泛的应用，从能量转换或化学处理的催化剂支撑到医疗植入物和生物学研究。这项工作的目标应用是模拟骨的化学成分、微观结构、孔隙度和表面形态的陶瓷结构。这些结构具有与骨相似的特性，被用于进行基础研究，如肿瘤细胞迁移和侵袭的研究以及药物筛选。研究生和本科生积极参与这一多学科的工作，获得对他们未来成功至关重要的技能。技术细节：这项EAGER资助研究了控制沉积在2D和3D聚氨酯（PUR）模板上的磷酸钙（CAP）薄膜的加工/性能/性能关系的基本机制，以形成具有类似骨骼特性的结构。在大多数应用中，陶瓷的表面组成和微观结构以及结构的孔径/孔隙率显著影响多孔陶瓷结构的性能。3D打印是一种令人兴奋的新方法，可以制造具有特定孔隙度和孔径的聚合物结构。采用低温原子层沉积工艺沉积共形CAP涂层。该项目涉及的科学问题包括2012年nsf赞助的研讨会上确定的陶瓷科学的八大挑战中的两个：1)预测和控制异质微观结构，以及2)控制远离平衡的陶瓷。罗杰斯教授在硅上使用2D结构，使用与制造3D结构相同的工艺制造，以研究CAP/PUR系统的化学成分，微观结构和机械性能如何随着加工条件的变化而变化。由于合成温度较低，沉积的CAP薄膜是无定形的。采用沉积后退火的方法研究了非晶态CAP结晶与温度分布和总热负荷的关系。固有的非平衡快速热退火过程促进了CAP薄膜中相和微观结构的形成，这是通过块状材料的热力学控制处理无法实现的。该项目涉及的主题范围广泛（硬材料和软材料、加工、表征、计算机编程、反应堆设计/建造、2D与3D材料），使项目团队的研究生和本科生能够接触到学术和工业研究以及解决问题的许多方面。他们通过这个项目获得的技能将在他们的整个职业生涯中受益。

NON-TECHNICAL DESCRIPTION: This EAGER project capitalizes on new deposition technologies and investigates the formation of ceramic films deposited onto polymer structures to better understand how the composition and microstructure of the ceramic depends on the deposition conditions. This information is critical to be able to fabricate three-dimensional ceramic structures by coating a polymer template with a ceramic film. Three-dimensional ceramic structures have a wide variety of applications, from catalyst supports for energy conversion or chemical processing to medical implants and biological studies. The target application for this work is ceramic structures that mimic the chemical composition, microstructure, porosity, and surface morphology of bone. With properties similar to bone, these structures are being used to perform fundamental studies, such as investigation of tumor cell migration and invasion as well as drug screening. Graduate and undergraduate students are actively involved in this multidisciplinary work, gaining skills important to their future success.TECHNICAL DETAILS: This EAGER grant investigates fundamental mechanisms controlling the processing/property/performance relationships of calcium phosphate (CAP) films deposited onto 2D and 3D polyurethane (PUR) templates to form structures with properties similar to bone. For most applications, the surface composition and microstructure of the ceramic, and the pore size/porosity of the structure significantly impact a porous ceramic structure's performance. 3D printing is an exciting new way to fabricate polymer structures with defined porosity and pore size. The conformal CAP coatings are deposited using a low temperature atomic layer deposition process. The scientific issues involved in this project encompass two of the eight grand challenges for ceramic science that were identified during a 2012 NSF-sponsored workshop: 1) predicting and controlling heterogeneous microstructures, and 2) control of ceramics far from equilibrium. Prof. Rogers uses 2D structures on silicon, fabricated using a process identical to that used to fabricate the 3D structure, to study how the chemical composition, microstructure, and mechanical properties of the CAP/PUR system evolve as a function of processing conditions. The as-deposited CAP films are amorphous due to the low synthesis temperature. Post-deposition annealing is used to investigate how the amorphous CAP crystallizes as a function of temperature profile and overall heat duty. The inherently non-equilibrium rapid thermal annealing process facilitates the formation of phases and microstructures in the thin CAP films that are not attainable through thermodynamically-controlled processing of bulk materials. The breadth of topics involved in this project (hard and soft materials, processing, characterization, computer programming, reactor design/construction, 2D vs. 3D materials) exposes the graduate and undergraduate students on the project team to many aspects of academic and industrial research and problem solving. The skills they attain through this project will benefit them throughout their career.