EAGER: Direct Ink Writing of Molecularly Patterned Polyionic Actuators

EARLY概念探索性研究（EAGER）奖支持的研究将展示聚合物材料的3D打印，这些材料通过其体积传输电荷，同时作为人造肌肉发挥作用，将热能转化为机械功。这项研究设想的一个关键突破是能够在聚合物网络内对齐离子物质，在打印过程中可以决定它们的组织，但在打印后仍然容易受到刺激的重新配置。实现这一点可以使多功能部件的制造能够影响一系列技术部门。具有可变的机械、电子和离子特性的可打印材料可以实现结构的新颖设计，如a）用于自由形式电池的可调电解质，B）用于软机器人的传感材料，其可以自我报告其致动状态，以及c）响应性生物材料，其可以主动调节其与微生物/生物制剂的相互作用。为了实现这一目标，关于工艺参数如何影响聚合物网络内带电物质的配置的基本问题仍有待回答。本研究将使用材料合成、制造工艺优化、表征技术和机械设计来解决这些问题。 这项研究将探索支撑3D打印离子液晶弹性体（LCE）可逆驱动的结构-性质-性能映射。将检查在由介晶丙烯酸酯和离子扩链剂组成的LCE的直接墨水书写（DIW）期间施加的挤出参数的影响。努力将集中在测量的剪切应力施加在打印过程中的分子排列的均匀性的影响，表征的分子结构对所得性能的作用，并利用这些表征在自由形式的人造肌肉，响应刺激。的LCE的分子有序状态的稳定性的骨干中的离子基团的效果将被探索作为一个功能的组合物，分子结构，和处理的历史。与典型液晶单体相容的离子单体将被合成以创建3D可打印墨水。将研究油墨的组成和DIW印刷参数以测量液晶有序性、相稳定性和结构的赋予。由此产生的样品将根据其对刺激的响应、其感知变形/应变的能力以及其与自由形式的软机器人架构的集成进行表征。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This EArly-concept Grant for Exploratory Research (EAGER) award supports research which will demonstrate 3D printing of polymeric materials that transport charges through their bulk, while simultaneously functioning as artificial muscles, which convert thermal energy into mechanical work. A key breakthrough envisioned by this research is the ability to align ionic species within a polymer network, where their organization can be dictated during the printing process but remain susceptible to reconfiguration using stimuli thereafter. Accomplishing this can enable the manufacturing of multifunctional components that could impact an array of technological sectors. Printable materials with mutable mechanical, electronic, and ionic properties may enable novel designs of structures like a) tunable electrolytes for freeform batteries, b) sensory materials for soft robots that can self-report their actuation state, and c) responsive biomaterials that can actively modulate their interaction with microbial/biological agents. To achieve this goal, fundamental questions on how process parameters affect the configuration of charged species within a polymer network remain to be answered. This research will address these issues using material synthesis, optimization of manufacturing processes, characterization techniques, and mechanical design. This research will explore the structure-property-performance mappings that underpin reversible actuation in 3D-printed, ionic liquid crystalline elastomers (LCE). The effect of extrusion parameters applied during direct ink writing (DIW) of LCE composed of mesogenic acrylates and ionic chain extenders will be examined. Efforts will focus on measuring the influence of the shear stresses imposed during the printing process on the homogeneity of the molecular alignment, characterizing the role of the molecular structure on the resulting properties, and harnessing these characterizations in freeform artificial muscles that respond to stimuli. The effect of the ionic groups in the backbone of the LCE on the stability of the molecularly ordered state will be explored as a function of the composition, molecular structure, and the processing history. Ionic monomers compatible with canonical liquid crystalline monomers will be synthesized to create 3D printable inks. The composition of the inks and the DIW printing parameters will be studied to measure the endowment of the liquid crystalline order, phase stability and structure. The resulting samples will be characterized for their actuation in response to stimuli, their ability to sense deformation/strain, and their integration into freeform soft robotic architectures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.